text: Unlike other radiometric dating techniques, those using the uranium decay series (except for those using the stable final isotopes Pb and Pb) compare the ratios of two radioactive unstable isotopes.  This complicates calculations as both the parent and daughter isotopes decay over time into other isotopes.

text: Unlike other radiometric dating techniques, those using the uranium decay series (except for those using the stable final isotopes Pb and Pb) compare the ratios of two

entity_name: Radioactive decay

text: radioactive

text: unstable isotopes.  This complicates calculations as both the parent and daughter isotopes decay over time into other isotopes.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Pb and Pb

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: uranium decay series

answers: NDQ_005715

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: the ratios of two radioactive unstable isotopes

answers: NDQ_005718

answers: complicates calculations

answers: NDQ_005719

answers: NDQ_005720

answers: no

answer_match: lowercase, stopped, stemmed, removed trailing period, fuzz > 0.8 / true-false special handling

orig_prompt_class: QuestionPromptWithChoices

prompt_style: context: question:

answers: NDQ_005711

answers: compare the ratios of two radioactive unstable isotopes.

answers: NDQ_005712

answers: uranium decay series

answers: NDQ_005713

answers: uranium decay series

answers: NDQ_005714

answers: compare the ratios of two radioactive unstable isotopes.

answers: NDQ_005715

answers: uranium decay series

answers: NDQ_005716

answers: uranium decay series

answers: NDQ_005717

answers: compare the ratios of two radioactive unstable isotopes.

answers: NDQ_005718

answers: complicates calculations

answers: NDQ_005719

answers: those using the uranium decay series

answers: NDQ_005720

answers: uranium decay series

answer_match: lowercase, stemmed, fuzz > 0.8

text: This technique allows the errors involved in K-Ar dating to be checked. Argon–argon dating has the advantage of not requiring determinations of potassium.  Modern methods of analysis allow individual regions of crystals to be investigated.  This method is important as it allows crystals forming and cooling during different events to be identified.

text: This technique allows the errors involved in K-Ar dating to be checked. Argon–argon dating has the advantage of not requiring determinations of potassium.  Modern methods of analysis allow individual regions of crystals to be investigated.  This method is important as it allows crystals forming and cooling during different events to be identified.

method: dangnt-nlp

answers: NDQ_005711

answers: K-Ar

answers: NDQ_005712

answers: K-Ar

answers: NDQ_005713

answers: NDQ_005714

answers: Argon–argon dating

answers: NDQ_005715

answers: K-Ar dating

answers: NDQ_005716

answers: K-Ar dating

answers: NDQ_005717

answers: argon–argon dating

answers: NDQ_005718

answers: K-Ar dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: Argon–argon

answers: NDQ_005712

answers: Argon–argon

answers: NDQ_005713

answers: Argon–argon dating

answers: NDQ_005714

answers: This technique allows the errors involved in K-Ar dating to be checked.

answers: NDQ_005715

answers: Argon–argon dating

answers: NDQ_005716

answers: K-Ar dating

answers: NDQ_005717

answers: not requiring determinations of potassium.

answers: NDQ_005718

answers: determinations of potassium.

answers: NDQ_005719

answers: Argon–argon dating

answers: NDQ_005720

answers: Argon–argon dating

text: Employers must update or reverify certain ID documents at or prior to their expiration date. This does not apply to already presented and accepted non-expired US Passports or Permanent Resident Cards when they reach their expiration date, nor to any List B documents, e.g. state driver's licenses and state ID's. The USCIS website, in the Employer section, Employer Bulletins, lists the limited requirements and allowed instances for reverification.

text: Employers must update or reverify certain ID documents at or prior to their expiration date. This does not apply to already presented and accepted non-expired US Passports or Permanent Resident Cards when they reach their expiration date, nor to any List B documents, e.g. state driver's licenses and state ID's. The USCIS website, in the Employer section, Employer Bulletins, lists the limited requirements and allowed instances for reverification.

method: Bert-ConvKNRM

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: List B documents

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: What does the USCIS website list the limited requirements and allowed instances for reverification

answers: NDQ_005718

answers: limited requirements and allowed instances for reverification

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: expiration date.

answers: NDQ_005712

answers: non-expired

answers: NDQ_005713

answers: List B documents,

answers: NDQ_005714

answers: expiration date.

answers: NDQ_005715

answers: List B

answers: NDQ_005716

answers: expiration date.

answers: NDQ_005717

answers: non-expired US Passports or Permanent Resident Cards

answers: NDQ_005718

answers: allowed instances for reverification.

answers: NDQ_005719

answers: non-expired US Passports or Permanent Resident Cards

answers: NDQ_005720

answers: Employers must update or reverify certain ID documents

text: Ten countries participated. It was France's first win. Sweden made its debut while the United Kingdom did not enter the contest for the second and last time to date, having missed the first contest two years earlier. As in 1956, it is the only contest that has not featured a single song in the English language. The 1958 contest continued with the policy implemented the year before where each country was limited to one song entry. This policy has been retained to date.

text: Ten countries participated. It was

entity_name: France in the Eurovision Song Contest

text: France's first win

entity_name: Sweden in the Eurovision Song Contest

text: Sweden

text: made its debut while the

entity_name: United Kingdom in the Eurovision Song Contest

text: United Kingdom

text: did not enter the contest for the second and last time to date, having missed the first contest two years earlier. As in 1956, it is the only contest that has not featured a single song in the English language. The 1958 contest continued with the policy implemented the year before where each country was limited to one song entry. This policy has been retained to date.

method: ICT-DRMMTKS

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: How many countries participated in the contest

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Ten countries

answers: NDQ_005712

answers: 1956,

answers: NDQ_005713

answers: France's first win. Sweden made its debut while the United Kingdom

answers: NDQ_005714

answers: Ten

answers: NDQ_005715

answers: France's first win. Sweden made its debut while the United Kingdom

answers: NDQ_005716

answers: Ten countries participated. It was France's first win.

answers: NDQ_005717

answers: 1956,

answers: NDQ_005718

answers: one song entry.

answers: NDQ_005719

answers: France's first win. Sweden made its debut while the United Kingdom

answers: NDQ_005720

answers: Ten countries participated. It was France's first win.

text: In 1958, de Vries showed that baffling anomalies in the carbon-14 dates, observed by Willard Frank Libby for Egyptological samples, were in fact systematic anomalies on a global scale, represented in the carbon-14 dates of tree rings. This phenomenon has been called the "de Vries effect". The correspondence with tree rings, which can be counted (one ring for each year), led to a recalibration of radiocarbon dating that was a large improvement in the accuracy.

text: In 1958, de Vries showed that baffling anomalies in the

text: dates, observed by

entity_name: Willard Libby

text: Willard Frank Libby

text: for

entity_name: Egyptology

text: Egyptological

text: samples, were in fact systematic anomalies on a global scale, represented in the carbon-14 dates of

entity_name: Dendrochronology

entity_section: Growth rings

text: tree ring

text: s. This phenomenon has been called the "de Vries effect". The correspondence with tree rings, which can be counted (one ring for each year), led to a recalibration of radiocarbon dating that was a large improvement in the accuracy.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: carbon-14

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: de Vries effect

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: carbon-14

answers: NDQ_005718

answers: accuracy

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: carbon-14 dates,

answers: NDQ_005712

answers: (one ring for each year),

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: accuracy.

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: carbon-14 dates,

answers: NDQ_005717

answers: (one ring for each year),

answers: NDQ_005718

answers: systematic anomalies on a global scale,

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: Archaeological evidence, based on the established chronology of Bronze Age Mediterranean cultures, dates the eruption to around 1500 BC. These dates, however, conflict with radiocarbon dating which indicates that the eruption occurred at about 1645–1600 BC. Around the time of the radiocarbon-indicated date of the eruption, there is evidence for a significant climatic event in the Northern Hemisphere.  The evidence includes failure of crops in China, as well as evidence from tree rings, and an ice core from Greenland. The tree rings date the climatic event to 1628 BC.

text: Archaeological evidence, based on the established chronology of Bronze Age Mediterranean cultures, dates the eruption to around 1500 BC. These dates, however, conflict with

entity_name: Radiocarbon dating

text: radiocarbon dating

text: which indicates that the eruption occurred at about 1645–1600 BC. Around the time of the radiocarbon-indicated date of the eruption, there is evidence for a significant climatic event in the Northern Hemisphere.  The evidence includes failure of crops in China, as well as evidence from

text: tree rings

text: , and an ice core from Greenland. The tree rings date the climatic event to 1628 BC.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: radiocarbon-indicated date

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: The tree rings date the climatic event to 1628 BC

answers: NDQ_005718

answers: conflict with radiocarbon dating

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 1645–1600 BC.

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 1645–1600 BC.

answers: NDQ_005718

answers: conflict with radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating

text: There was unusual stratigraphic and radiometric control at Border Cave, and these data indicate that Border Cave was not always inhabited. Border cave was occupied at different points in time, and each occupancy modified the sediment at Border Cave. One particular sedimentary sequence of interest was the early age of the Middle Stone Age at about 95,000 B.P., which was originally believed to align with the Upper Paleolithic. Instead, the Middle Stone Age at Border Cave was found to extend to the beginning of the Late Interglacial. A number of sedimentary sequences on the interior and the coast, including the Klasies River Mouth site in the southern Cape, the Bushman Rock Shelter, and Florisbad, support this sedimentary pattern presented at Border Cave. Additionally, a late Middle Pleistocene age for the earliest Middle Stone Age follows the uranium-series date of 174,000 B.P.

text: There was unusual stratigraphic and radiometric control at Border Cave, and these data indicate that Border Cave was not always inhabited. Border cave was occupied at different points in time, and each occupancy modified the sediment at Border Cave. One particular sedimentary sequence of interest was the early age of the Middle Stone Age at about 95,000 B.P., which was originally believed to align with the Upper Paleolithic. Instead, the Middle Stone Age at Border Cave was found to extend to the beginning of the Late Interglacial. A number of sedimentary sequences on the interior and the coast, including the

entity_name: Klasies River Caves

text: Klasies River Mouth

text: site in the southern Cape, the Bushman Rock Shelter, and

entity_name: Florisbad

text: Florisbad

text: , support this sedimentary pattern presented at Border Cave. Additionally, a late Middle Pleistocene age for the earliest Middle Stone Age follows the uranium-series date of 174,000 B.P.

answers: NDQ_005711

answers: radiometric control

answers: NDQ_005712

answers: Middle Stone Age

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: uranium-series

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: uranium

answers: NDQ_005717

answers: 174,000 B.P.

answers: NDQ_005718

answers: uranium-series date

answers: NDQ_005719

answers: How old is the Middle Stone Age at Border Cave?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: uranium-series

answers: NDQ_005712

answers: uranium-series

answers: NDQ_005713

answers: 95,000 B.P.,

answers: NDQ_005714

answers: uranium-series

answers: NDQ_005715

answers: 95,000 B.P.,

answers: NDQ_005716

answers: uranium-series

answers: NDQ_005717

answers: 174,000 B.P.

answers: NDQ_005718

answers: Border Cave was not always inhabited.

answers: NDQ_005719

answers: uranium-series date of 174,000 B.P.

answers: NDQ_005720

answers: uranium-series date of 174,000 B.P.

text: Radiometric dating or radioactive dating is a technique used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were  formed. The method compares the abundance of a naturally occurring radioactive isotope within the material to the abundance of its decay products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by Bertram Boltwood and is now the principal source of information about the absolute age of rocks and other geological features, including the age of fossilized life forms or the age of the Earth itself, and can also be used to date a wide range of natural and man-made materials.

text: Radiometric dating or radioactive dating is a technique used to

entity_name: Chronological dating

text: date

text: materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were  formed. The method compares the abundance of a naturally occurring radioactive

entity_name: Isotope

text: isotope

text: within the material to the abundance of its

text: decay

text: products, which form at a known constant rate of decay. The use of radiometric dating was first published in 1907 by

entity_name: Bertram Boltwood

text: Bertram Boltwood

text: and is now the principal source of information about the

entity_name: Absolute dating

text: absolute age

text: of rocks and other

entity_name: Geology

text: geological features

text: , including the age of

entity_name: Paleontology

text: fossilized life forms

text: or the

entity_name: Age of the Earth

text: age of the Earth

text: itself, and can also be used to date a wide range of natural and

entity_name: Artifact (archaeology)

text: man-made materials

method: UvABottomUpChangeOrder

method: UNH-qee

answers: NDQ_005711

answers: the abundance of a naturally occurring radioactive isotope

answers: NDQ_005712

answers: natural and man-made materials

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating was first published in 1907

answers: NDQ_005715

answers: NDQ_005716

answers: decay products form

answers: NDQ_005717

answers: radioactive impurities were selectively incorporated when they were formed

answers: NDQ_005718

answers: constant rate of decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: compares the abundance of a naturally occurring radioactive isotope

answers: NDQ_005712

answers: absolute age

answers: NDQ_005713

answers: a known constant rate of decay.

answers: NDQ_005714

answers: fossilized life forms

answers: NDQ_005715

answers: Radiometric dating

answers: NDQ_005716

answers: form at a known constant rate of decay.

answers: NDQ_005717

answers: form at a known constant rate of decay.

answers: NDQ_005718

answers: form at a known constant rate of decay.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: The only known specimens of Teratophoneus were recovered at the Kaiparowits Formation, in southern Utah. Argon-argon radiometric dating indicates that the fossils were buried during the Campanian stage of the Late Cretaceous period. During the Late Cretaceous period, the site within the Kaiparowits Formation was located on Laramidia near its eastern shore on the Western Interior Seaway, a large inland sea that split North America into two landmasses, the other being Appalachia to the east. The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and an abundance of wetland peat swamps, ponds and lakes, and was bordered by highlands. The climate was wet and humid, and supported an array of different and diverse groups of organisms. This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world.

text: The only known specimens of Teratophoneus were recovered at the Kaiparowits Formation, in southern Utah.

entity_name: Argon–argon dating

text: Argon-argon radiometric dating

text: indicates that the fossils were buried during the Campanian stage of the Late

entity_name: Cretaceous

text: Cretaceous

text: period. During the Late Cretaceous period, the site within the Kaiparowits Formation was located on

entity_name: Laramidia

text: Laramidia

text: near its eastern shore on the

entity_name: Western Interior Seaway

text: Western Interior Seaway

text: , a large inland sea that split North America into two landmasses, the other being

entity_name: Appalachia

text: Appalachia

text: to the east. The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and an abundance of wetland

entity_name: Peat

text: peat

text: swamps, ponds and lakes, and was bordered by highlands. The climate was wet and humid, and supported an array of different and diverse groups of organisms. This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Argon-argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Argon-argon radiometric dating

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the fossils were buried during the Campanian stage of the Late Cretaceous period

answers: NDQ_005718

answers: Argon-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Argon-argon

answers: NDQ_005712

answers: Argon-argon

answers: NDQ_005713

answers: Argon-argon

answers: NDQ_005714

answers: Argon-argon radiometric

answers: NDQ_005715

answers: Argon-argon

answers: NDQ_005716

answers: buried

answers: NDQ_005717

answers: Campanian stage of the Late Cretaceous period.

answers: NDQ_005718

answers: Argon-argon radiometric dating

answers: NDQ_005719

answers: Argon-argon radiometric dating

answers: NDQ_005720

answers: Argon-argon radiometric dating

text: Many geologists felt these new discoveries made radiometric dating so complicated as to be worthless. Holmes felt that they gave him tools to improve his techniques, and he plodded ahead with his research, publishing before and after the First World War. His work was generally ignored until the 1920s, though in 1917 Joseph Barrell, a professor of geology at Yale, redrew geological history as it was understood at the time to conform to Holmes's findings in radiometric dating. Barrell's research determined that the layers of strata had not all been laid down at the same rate, and so current rates of geological change could not be used to provide accurate timelines of the history of Earth.

text: Many geologists felt these new discoveries made radiometric dating so complicated as to be worthless. Holmes felt that they gave him tools to improve his techniques, and he plodded ahead with his research, publishing before and after the First World War. His work was generally ignored until the 1920s, though in 1917

entity_name: Joseph Barrell

text: Joseph Barrell

text: , a professor of geology at Yale, redrew geological history as it was understood at the time to conform to Holmes's findings in radiometric dating. Barrell's research determined that the layers of strata had not all been laid down at the same rate, and so current rates of geological change could not be used to provide accurate timelines of the history of Earth.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: current rates of geological change

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Joseph Barrell, a professor of geology at Yale, redrew geological history as it was understood at the time to conform to Holmes's findings

answers: NDQ_005718

answers: layers of strata had not all been laid down at the same rate

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: the layers of strata had not all been laid down at the same rate,

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: Joseph Barrell,

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the layers of strata had not all been laid down at the same rate,

answers: NDQ_005718

answers: complicated

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Recent radiometric age data indicates that there are four crystalline rock complexes 3,400 million years old in the Lake Superior region. The best-known units are the Morton Gneiss and the Montevideo Gneiss complexes, along the Minnesota River Valley in southwest Minnesota. Rocks exposed in the Minnesota River Valley include a complex of migmatitic granitic gneisses, schistose to gneissic amphibolite, metagabbro and paragneisses. The complex of ancient gneisses is intruded by a younger, weakly deformed granite body, the Sacred Heart granite.

text: Recent

entity_name: Radiometric dating

text: radiometric

text: age data indicates that there are four crystalline rock complexes 3,400 million years old in the Lake Superior region. The best-known units are the Morton Gneiss and the Montevideo Gneiss complexes, along the Minnesota River Valley in southwest Minnesota. Rocks exposed in the Minnesota River Valley include a complex of migmatitic granitic gneisses, schistose to gneissic

entity_name: Amphibolite

text: amphibolite

text: , metagabbro and paragneisses. The complex of ancient gneisses is intruded by a younger, weakly deformed granite body, the Sacred Heart granite.

answers: NDQ_005711

answers: radiometric age

answers: NDQ_005712

answers: crystalline rock complexes

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric age

answers: NDQ_005717

answers: radiometric age data indicates that there are four crystalline rock complexes 3,400 million years old in the Lake Superior region

answers: NDQ_005718

answers: weakly deformed granite body

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 3,400 million years old

answers: NDQ_005712

answers: 3,400 million years old

answers: NDQ_005713

answers: 3,400 million years old

answers: NDQ_005714

answers: radiometric age

answers: NDQ_005715

answers: Sacred Heart granite.

answers: NDQ_005716

answers: radiometric age

answers: NDQ_005717

answers: 3,400 million years old

answers: NDQ_005718

answers: weakly deformed

answers: NDQ_005719

answers: weakly deformed granite body, the Sacred Heart granite.

answers: NDQ_005720

answers: 3,400 million years old in the Lake Superior region.

text: The American Scientific Affiliation (ASA) was founded in 1941 as a less confrontational forum for evangelical scientists, led by F. Alton Everest. Deluge geologists including Lammerts and Price urged close cooperation with the DGS, but Everest began to see their views as presenting an "insurmountable problem" for the ASA. In 1948 he requested J. Laurence Kulp, a geologist in fellowship with the Plymouth Brethren, to explore the issue. At the convention that year, Kulp examined hominid antiquity demonstrated by radiocarbon dating. At the 1949 convention a paper by Kulp was presented, giving a detailed critique of Deluge Geology, which he said had "grown and infiltrated the greater portion of fundamental Christianity in America primarily due to the absence of trained Christian geologists". He demonstrated that "major propositions of the theory are contraindicated by established physical and chemical laws". Kulp focused on "four basic errors" commonly made by flood geologists – saying that geology was the same as evolution; assuming "that life has been on the earth only for a few thousand years, [and] therefore the flood must account for geological strata"; misunderstanding "the physical and chemical conditions under which rocks are formed"; and ignoring recent discoveries such as radiometric dating that undermined their assumptions. He accused Price of ignorance and deception, and concluded that "this unscientific theory of flood geology has done and will do considerable harm to the strong propagation of the gospel among educated people." Price said nothing during the presentation and discussion. When invited to speak, he "said something very brief which missed what everyone was waiting for". Further publications made the ASA's opposition to flood geology clear.

text: The

entity_name: American Scientific Affiliation

text: American Scientific Affiliation

text: (ASA) was founded in 1941 as a less confrontational forum for

entity_name: Evangelicalism

text: evangelical

text: scientists, led by

entity_name: F. Alton Everest

text: F. Alton Everest

text: . Deluge geologists including Lammerts and Price urged close cooperation with the DGS, but Everest began to see their views as presenting an "insurmountable problem" for the ASA. In 1948 he requested

entity_name: J. Laurence Kulp

text: J. Laurence Kulp

text: , a geologist in fellowship with the

entity_name: Plymouth Brethren

text: Plymouth Brethren

text: , to explore the issue. At the convention that year, Kulp examined

entity_name: Hominidae

text: hominid

text: antiquity demonstrated by

text: radiocarbon dating

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: radiometric dating that undermined their assumptions

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiometric dating that undermined their assumptions

answers: NDQ_005718

answers: ignoring recent discoveries

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: radiocarbon dating.

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: ignoring recent discoveries

answers: NDQ_005714

answers: radiocarbon dating.

answers: NDQ_005715

answers: J. Laurence Kulp,

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: ignoring recent discoveries such as radiometric dating

answers: NDQ_005718

answers: undermined their assumptions.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Discrepancies between dates obtained by surface exposure dating and potassium-argon dating on some rocks have been interpreted as being due to lava flows being covered by snow and ice in the past. From this it has been inferred that the Ashikule field was covered by glaciers during the Last Glacial Maximum, when temperatures decreased by .

text: Discrepancies between dates obtained by

entity_name: Surface exposure dating

text: surface exposure dating

text: and

entity_name: K–Ar dating

text: potassium-argon dating

text: on some rocks have been interpreted as being due to lava flows being covered by snow and ice in the past. From this it has been inferred that the Ashikule field was covered by

entity_name: Glacier

text: glacier

text: s during the

entity_name: Last Glacial Maximum

text: Last Glacial Maximum

text: , when temperatures decreased by .

answers: NDQ_005711

answers: surface exposure dating

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: surface exposure dating

answers: NDQ_005718

answers: discrepancies

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: surface exposure dating

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: surface exposure dating and potassium-argon

answers: NDQ_005717

answers: lava flows being covered by snow and ice

answers: NDQ_005718

answers: Discrepancies between dates

answers: NDQ_005719

answers: surface exposure dating

answers: NDQ_005720

answers: potassium-argon dating

text: Receiving his doctorate engineering in 1972, Khan joined the senior staff of the Physics Dynamics Research Laboratory in Amsterdam from a recommendation by his mentor, Martin J. Brabers. His initial studies were on the high-strength metals used in the development of centrifuges. Gas centrifuges were first conceived by American physicist Jesse Beams as part of the Manhattan Project but the studies were discontinued in 1944. The Physics Laboratory was a subcontractor for Urenco Group which was operating a uranium-enrichment plant in Almelo, Netherlands. Established in 1970, Urenco employed the centrifuge method to assure a supply of enriched uranium for nuclear power plants in the Netherlands. When Urenco offered him to join the senior scientific staff there, Khan left the Physics Laboratory where he performed physics experiments on uranium metallurgy, to produce reactor-grade uranium usable for light water reactors. Urenco used the Zippe-type gas centrifuges— a method invented by German mechanical engineer Gernot Zippe in the Soviet Union's program. Enrichment of uranium is an extremely difficult physical process, as U exists in natural uranium at a concentration of only 0.7%; Urenco used the Zippe method to separate the fissile isotopes U from non-fissile U by spinning UF gas at up to ~100,000RPM. His pioneering research led to the improvement of the Zippe method, which at that time, was an emerging technology whose publications were classified by the Soviet Union. Khan's leading-edge research in metallurgy brought laurels to Urenco, which had him as one of the most senior scientists at the facility where he researched and studied. His pioneering research greatly improved the technological efficiency of the Zippe method; eventually, Urenco gave Khan access to the blueprints for the Zippe centrifuge to find mathematical solutions for the physics problems in the gas centrifuges.

text: Receiving his

entity_name: Doctor of Engineering

text: doctorate engineering

text: in 1972, Khan joined the senior staff of the Physics Dynamics Research Laboratory in

entity_name: Amsterdam

text: Amsterdam

text: from a recommendation by his mentor, Martin J. Brabers. His initial studies were on the

entity_name: High-strength low-alloy steel

text: high-strength metals

text: used in the development of

entity_name: Gas centrifuge

text: centrifuges

text: Gas centrifuges

text: were first conceived by

entity_name: United States

text: American

entity_name: Physicist

text: physicist

text: Jesse Beams

text: as part of the

text: Manhattan Project

text: but the studies were discontinued in 1944. The Physics Laboratory was a subcontractor for

text: Urenco Group

text: which was operating a

text: uranium-enrichment

text: plant in

text: Almelo

text: Netherlands

text: . Established in 1970,

text: Urenco

text: employed the centrifuge method to assure a supply of

text: enriched uranium

text: for

text: nuclear power plants in the Netherlands

text: . When

text: Urenco

text: offered him to join the senior scientific staff there, Khan left the Physics Laboratory where he performed physics experiments on

text: uranium metallurgy

text: , to produce

text: reactor-grade

text: uranium

text: usable for

text: light water

text: reactors.

text: Urenco

text: used the

text: Zippe-type

text: gas centrifuges

text: — a

entity_name: Forced labor of Germans in the Soviet Union

text: method invented

text: by

text: German

text: mechanical engineer

text: Gernot Zippe

text: in the

text: Soviet Union

text: 's

text: program

text: Enrichment

text: of

text: uranium

text: is an extremely difficult

text: physical process

text: , as

text: U

text: exists in

text: natural uranium

text: at a concentration of only 0.7%;

text: Urenco

text: used the

text: Zippe method

text: to separate the

text: fissile

text: isotope

text: s

text: U

text: from non-fissile

text: U

text: by spinning

text: UF

text: gas at up to ~100,000

text: RPM

text: . His pioneering research led to the improvement of the

text: Zippe method

text: , which at that time, was an

text: emerging technology

text: whose publications were

text: classified

text: by the

text: Soviet Union

text: . Khan's leading-edge research in

text: metallurgy

text: brought laurels to

text: Urenco

text: , which had him as one of the most senior scientists at the facility where he researched and studied. His pioneering research greatly improved the technological

text: efficiency

text: of the

text: Zippe method

text: ; eventually,

text: Urenco

text: gave Khan access to the

text: blueprint

text: s for the

text: Zippe centrifuge

text: to find mathematical solutions for the physics problems in the

text: gas centrifuge

text: s.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: natural uranium

answers: NDQ_005713

answers: What is the Zippe method?

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: gas centrifuges— a method invented by German mechanical engineer Gernot Zippe in the Soviet Union's program

answers: NDQ_005718

answers: Enrichment of uranium

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: Gernot Zippe

answers: NDQ_005712

answers: Enrichment of uranium

answers: NDQ_005713

answers: Zippe-type gas centrifuges—

answers: NDQ_005714

answers: Gernot Zippe in the Soviet Union's program.

answers: NDQ_005715

answers: gas centrifuges.

answers: NDQ_005716

answers: Enrichment of uranium

answers: NDQ_005717

answers: Urenco used the Zippe method

answers: NDQ_005718

answers: Enrichment of uranium is an extremely difficult physical process,

answers: NDQ_005719

answers: gas centrifuges.

answers: NDQ_005720

answers: Zippe-type gas centrifuges—

text: Since the Tumblagooda sandstone comprises a sedimentary succession with no volcanic layers (which could be dated radiometrically) and with virtually no body fossils, its age is very difficult to constrain. It was first thought to have formed around , during the Cretaceous period, on the basis of stratigraphy; current estimates place it far earlier, in the lower Ordovician, . It is hoped that a new technique based on the uranium-thorium dating of diagenetic monazite crystals may produce a more precise estimate of the age, but initial attempts have failed to extract sufficient monazite from the unit.

text: Since the Tumblagooda sandstone comprises a sedimentary succession with no volcanic layers (which could be

text: dated radiometrically

text: ) and with virtually no body fossils, its age is very difficult to constrain. It was first thought to have formed around , during the

text: Cretaceous

text: period, on the basis of stratigraphy; current estimates place it far earlier, in the lower

text: Ordovician

text: , . It is hoped that a new technique based on the

text: uranium-thorium dating

text: of

text: diagenetic

text: monazite

text: crystals may produce a more precise estimate of the age, but initial attempts have failed to extract sufficient monazite from the unit.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: volcanic layers

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: initial attempts have failed to extract sufficient monazite from the unit

answers: NDQ_005718

answers: no volcanic layers

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: volcanic layers

answers: NDQ_005712

answers: volcanic layers

answers: NDQ_005713

answers: radiometrically)

answers: NDQ_005714

answers: radiometrically)

answers: NDQ_005715

answers: uranium-thorium

answers: NDQ_005716

answers: fossils,

answers: NDQ_005717

answers: diagenetic monazite crystals

answers: NDQ_005718

answers: no volcanic layers

answers: NDQ_005719

answers: uranium-thorium

answers: NDQ_005720

answers: uranium-thorium

text: Steep contacts between the thick basal breccia of Mount Silverthrone and older crystalline rocks of adjacent peaks suggest that the breccia is part of a caldera-fill succession. The presence of irregular subvolcanic intrusions and a profusion of dikes within the breccia—but not in adjacent country rock—provide further evidence of the Silverthrone Caldera. Potassium-argon dates of 750,000 and 400,000 years on rhyolitic lava domes above the basal breccia are consistent with the high rates of uplift and erosion recorded elsewhere in the Coast Mountains.

text: Steep contacts between the thick basal

text: breccia

text: of Mount Silverthrone and older crystalline rocks of adjacent peaks suggest that the breccia is part of a caldera-fill succession. The presence of irregular subvolcanic intrusions and a profusion of

text: dike

text: s within the breccia—but not in adjacent country rock—provide further evidence of the Silverthrone Caldera.

text: Potassium-argon dates

text: of 750,000 and 400,000 years on

text: rhyolitic

text: lava dome

text: s above the basal breccia are consistent with the high rates of uplift and

text: erosion

text: recorded elsewhere in the Coast Mountains.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: Potassium-argon

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: Potassium-argon

answers: NDQ_005715

answers: NDQ_005716

answers: argon

answers: NDQ_005717

answers: 750,000 and 400,000 years

answers: NDQ_005718

answers: Potassium-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: Potassium-argon dates of 750,000 and 400,000 years

answers: NDQ_005713

answers: Potassium-argon

answers: NDQ_005714

answers: Potassium-argon

answers: NDQ_005715

answers: Potassium-argon

answers: NDQ_005716

answers: Potassium-argon

answers: NDQ_005717

answers: 750,000 and 400,000 years

answers: NDQ_005718

answers: high rates of uplift and erosion

answers: NDQ_005719

answers: Potassium-argon dates of 750,000 and 400,000 years

answers: NDQ_005720

answers: Potassium-argon

text: Radiocarbon dating measurements produce ages in "radiocarbon years", which must be converted to calendar ages by a process called calibration.  Calibration is needed because the atmospheric / ratio, which is a key element in calculating radiocarbon ages, has not been constant historically. Although Willard Libby, the inventor of radiocarbon dating, had pointed out as early as 1955 the possibility that the / ratio might have varied over time, it was not until discrepancies began to accumulate between measured ages and known historical dates for artefacts that it became clear that a correction would need to be applied to radiocarbon ages to obtain calendar dates. Radiocarbon years ago may be abbreviated ya (years ago). A general term used reflecting evidence from any method is Before Present (BP).

text: Radiocarbon dating

text: measurements produce ages in "radiocarbon years", which must be converted to calendar ages by a process called calibration.  Calibration is needed because the atmospheric / ratio, which is a key element in calculating radiocarbon ages, has not been constant historically. Although

text: Willard Libby

text: , the inventor of radiocarbon dating, had pointed out as early as 1955 the possibility that the / ratio might have varied over time, it was not until discrepancies began to accumulate between measured ages and known historical dates for artefacts that it became clear that a correction would need to be applied to radiocarbon ages to obtain calendar dates. Radiocarbon years ago may be abbreviated ya (years ago). A general term used reflecting evidence from any method is

text: Before Present

text: (BP).

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: the atmospheric / ratio has not been constant historically

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radiocarbon years

answers: NDQ_005717

answers: Calibration is needed

answers: NDQ_005718

answers: Calibration is needed

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon dating measurements produce ages in "radiocarbon years",

answers: NDQ_005712

answers: "radiocarbon years",

answers: NDQ_005713

answers: Radiocarbon dating measurements produce ages in "radiocarbon years",

answers: NDQ_005714

answers: Calibration is needed because the atmospheric / ratio,

answers: NDQ_005715

answers: Radiocarbon dating measurements produce ages in "radiocarbon years",

answers: NDQ_005716

answers: ages in "radiocarbon years",

answers: NDQ_005717

answers: calibration. Calibration is needed because the atmospheric / ratio,

answers: NDQ_005718

answers: has not been constant historically.

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: calibration.

text: The only known specimen of Hagryphus was recovered at the Kaiparowits Formation, in southern Utah.  Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous period.  During the Late Cretaceous period, the  site of the Kaiparowits Formation was located near the western shore of the Western Interior Seaway,  a large inland sea that split North America into two landmasses, Laramidia to the west and Appalachia to the east.  The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and abundant wetland peat swamps, ponds and lakes, and was bordered by highlands.  The climate was wet and humid, and supported an abundant and diverse range of organisms.  This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world.

text: The only known specimen of Hagryphus was recovered at the

text: Kaiparowits Formation

text: , in southern Utah.

text: Argon-argon radiometric dating

text: indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late

text: Cretaceous

text: period.  During the Late Cretaceous period, the  site of the Kaiparowits Formation was located near the western shore of the

text: Western Interior Seaway

text: ,  a large inland sea that split North America into two landmasses,

text: Laramidia

text: to the west and

text: Appalachia

text: to the east.  The plateau where dinosaurs lived was an ancient floodplain dominated by large channels and abundant wetland

text: peat

text: swamps, ponds and lakes, and was bordered by highlands.  The climate was wet and humid, and supported an abundant and diverse range of organisms.  This formation contains one of the best and most continuous records of Late Cretaceous terrestrial life in the world.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Argon-argon

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: Argon-argon radiometric dating

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating measures when the organism died

answers: NDQ_005717

answers: the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago

answers: NDQ_005718

answers: continuous records

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Argon-argon

answers: NDQ_005712

answers: between 76.1 and 74.0 million years ago,

answers: NDQ_005713

answers: Argon-argon

answers: NDQ_005714

answers: Argon-argon radiometric dating

answers: NDQ_005715

answers: Argon-argon

answers: NDQ_005716

answers: Argon-argon radiometric dating

answers: NDQ_005717

answers: between 76.1 and 74.0 million years ago,

answers: NDQ_005718

answers: Argon-argon

answers: NDQ_005719

answers: Argon-argon radiometric dating

answers: NDQ_005720

answers: Argon-argon radiometric dating

text: Radiocarbon dating conducted by the Lawrence Livermore National Laboratory in June 2002 established that the anthrax was cultured no more than two years before the mailings.

text: Radiocarbon dating

text: conducted by the

text: Lawrence Livermore National Laboratory

text: in June 2002 established that the anthrax was

text: cultured

text: no more than two years before the mailings.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon dating

answers: NDQ_005718

answers: no more than two years

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon

answers: NDQ_005715

answers: Radiocarbon dating conducted by the Lawrence Livermore National Laboratory

answers: NDQ_005716

answers: Radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon

answers: NDQ_005718

answers: no more than two years before the mailings.

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: In October 1996, Hanlin, Beikthano, and Sri Kestra were proposed to be inscribed on the UNESCO World Heritage List. This proposal was approved by UNESCO in the 38th session of the World Heritage Committee held in May 2014 in Doha, Qatar. According to the UNESCO report, the Pyu Kingdom prospered for over 1,000 years between 200 BC and 900 AD. All three sites are inscribed under Criterion (ii), (iii), and (iv) covering an area of  with a buffer zone of . The integrity assessment by UNESCO of the three sites is: "The completeness and reliability of dated archaeological sequences from the site, with the radiocarbon dates derived from intact architectural features dating back to 190 BCE, provide scientific proof of the entire one-thousand year period of occupation of the cities, and reinforces palaeographic dates provided by inscriptions in Pyu script on artifacts excavated at the site"

text: In October 1996, Hanlin, Beikthano, and Sri Kestra were proposed to be inscribed on the

text: UNESCO World Heritage List

text: . This proposal was approved by

text: UNESCO

text: in the 38th session of the World Heritage Committee held in May 2014 in Doha, Qatar. According to the UNESCO report, the Pyu Kingdom prospered for over 1,000 years between 200 BC and 900 AD. All three sites are inscribed under Criterion (ii), (iii), and (iv) covering an area of  with a buffer zone of . The integrity assessment by UNESCO of the three sites is: "The completeness and reliability of dated archaeological sequences from the site, with the radiocarbon dates derived from intact architectural features dating back to 190 BCE, provide scientific proof of the entire one-thousand year period of occupation of the cities, and reinforces

text: palaeographic

text: dates provided by inscriptions in Pyu script on artifacts excavated at the site"

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon dates derived from intact architectural features dating back to 190 BCE

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon dates derived from intact architectural features

answers: NDQ_005712

answers: intact architectural features dating back to 190 BCE,

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: provide scientific proof

answers: NDQ_005715

answers: 190 BCE,

answers: NDQ_005716

answers: intact architectural features dating back to 190 BCE,

answers: NDQ_005717

answers: 190 BCE,

answers: NDQ_005718

answers: intact architectural features

answers: NDQ_005719

answers: 190 BCE,

answers: NDQ_005720

answers: radiocarbon

text: For many geologic applications, isotope ratios of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular closure temperature, the point at which different radiometric isotopes stop diffusing into and out of the crystal lattice. These are used in geochronologic and thermochronologic studies. Common methods include uranium-lead dating, potassium-argon dating, argon-argon dating and uranium-thorium dating. These methods are used for a variety of applications. Dating of lava and volcanic ash layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units which do not contain radioactive isotopes and calibrate relative dating techniques. These methods can also be used to determine ages of pluton emplacement. Thermochemical techniques can be used to determine temperature profiles within the crust, the uplift of mountain ranges, and paleotopography.

text: For many geologic applications,

text: isotope ratio

text: s of radioactive elements are measured in minerals that give the amount of time that has passed since a rock passed through its particular

text: closure temperature

text: , the point at which different radiometric isotopes stop diffusing into and out of the

text: crystal lattice

text: . These are used in

text: geochronologic

text: and

text: thermochronologic

text: studies. Common methods include

text: uranium-lead dating

text: potassium-argon dating

text: argon-argon dating

text: and

text: uranium-thorium dating

text: . These methods are used for a variety of applications. Dating of

text: lava

text: and

text: volcanic ash

text: layers found within a stratigraphic sequence can provide absolute age data for sedimentary rock units which do not contain radioactive isotopes and calibrate relative dating techniques. These methods can also be used to determine ages of

text: pluton

text: emplacement. Thermochemical techniques can be used to determine temperature profiles within the crust, the uplift of mountain ranges, and paleotopography.

answers: NDQ_005711

answers: isotope ratios

answers: NDQ_005712

answers: uranium-lead

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: isotope ratios of radioactive elements are measured in minerals

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: uranium-lead dating

answers: NDQ_005717

answers: argon-argon dating and uranium-thorium dating

answers: NDQ_005718

answers: isotope ratios

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: since a rock passed through its particular closure temperature,

answers: NDQ_005712

answers: do not contain radioactive isotopes

answers: NDQ_005713

answers: closure temperature,

answers: NDQ_005714

answers: calibrate relative dating techniques.

answers: NDQ_005715

answers: geochronologic and thermochronologic studies.

answers: NDQ_005716

answers: different radiometric isotopes stop diffusing

answers: NDQ_005717

answers: potassium-argon dating,

answers: NDQ_005718

answers: stop diffusing into and out of the crystal lattice.

answers: NDQ_005719

answers: argon-argon dating

answers: NDQ_005720

answers: uranium-lead dating,

text: On June 6, 2011, at E3 2011, Sony announced that the device's official name would be the PlayStation Vita, with the word "vita" being Latin for "life". Despite reports of the 2011 earthquakes in Japan delaying the release of the device, Sony reconfirmed that it was on track for a late 2011 release in Japan and a February 2012 release date for other major regions of the world. The release date was later narrowed down to a December 17, 2011, release in Japan, and a February 22, 2012 release date for America and Europe, although a limited edition was released a week earlier in North America on February 15, 2012, which included the 3G/WiFi model of the device, the game Little Deviants, a limited-edition carry case, and a 4 GB memory card. The Vita launched with 26 titles in Japan, with Sony announcing that there were over 100 titles in development prior to the system's release overall. The Vita launched in the west with 25 titles, including original titles such as Uncharted: Golden Abyss and Wipeout 2048, and ports of games such as FIFA 12 and Rayman Origins.

text: On June 6, 2011, at

text: E3 2011

text: , Sony announced that the device's official name would be the PlayStation Vita, with the word "vita" being Latin for "life". Despite reports of the

text: 2011 earthquakes in Japan

text: delaying the release of the device, Sony reconfirmed that it was on track for a late 2011 release in Japan and a February 2012 release date for other major regions of the world. The release date was later narrowed down to a December 17, 2011, release in Japan, and a February 22, 2012 release date for America and Europe, although a limited edition was released a week earlier in North America on February 15, 2012, which included the 3G/WiFi model of the device, the game

text: Little Deviants

text: , a limited-edition carry case, and a 4 GB memory card. The Vita launched with 26 titles in Japan, with Sony announcing that there were over 100 titles in development prior to the system's release overall. The Vita launched in the west with 25 titles, including original titles such as

text: Uncharted: Golden Abyss

text: and

text: Wipeout 2048

text: , and ports of games such as

text: FIFA 12

text: and

text: Rayman Origins

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: materials of these ages

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: in potassium-argon dating

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 26

answers: NDQ_005712

answers: "life".

answers: NDQ_005713

answers: 25 titles,

answers: NDQ_005714

answers: PlayStation Vita,

answers: NDQ_005715

answers: 25

answers: NDQ_005716

answers: "life".

answers: NDQ_005717

answers: 25

answers: NDQ_005718

answers: "life".

answers: NDQ_005719

answers: 25

answers: NDQ_005720

answers: 25

text: The analysis of 27 radiocarbon dates indicates that the site was initially occupied around 4000 BCE during the Middle Archaic period. Mound construction began at approximately 3500 BCE, and continued for approximately 500 years.  During that time period, the mounds were enlarged in several stages. Excavations indicate that there was sufficient time between building episodes for midden deposits of residents to accumulate on top of the mounds and ridges. In addition, teams from the University of Texas at Austin and the University of Washington dated the site by using sand grains and organic acids in the soils.

text: The analysis of 27

text: radiocarbon dates

text: indicates that the site was initially occupied around 4000 BCE during the Middle

text: Archaic period

text: . Mound construction began at approximately 3500 BCE, and continued for approximately 500 years.  During that time period, the mounds were enlarged in several stages. Excavations indicate that there was sufficient time between building episodes for

text: midden

text: deposits of residents to accumulate on top of the mounds and ridges. In addition, teams from the University of Texas at Austin and the University of Washington dated the site by using sand grains and organic acids in the soils.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: sand grains and organic acids

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: sand grains and organic acids in the soils.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: sand grains and organic acids in the soils.

answers: NDQ_005715

answers: 4000 BCE

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: sand grains and organic acids in the soils.

answers: NDQ_005718

answers: sand grains and organic acids in the soils.

answers: NDQ_005719

answers: sand grains and organic acids in the soils.

answers: NDQ_005720

answers: sand grains and organic acids in the soils.

text: The basic equation of radiometric dating requires that neither the parent nuclide nor the daughter product can enter or leave the material after its formation. The possible confounding effects of contamination of parent and daughter isotopes have to be considered, as do the effects of any loss or gain of such isotopes since the sample was created. It is therefore essential to have as much information as possible about the material being dated and to check for possible signs of alteration. Precision is enhanced if measurements are taken on multiple samples from different locations of the rock body. Alternatively, if several different minerals can be dated from the same sample and are assumed to be formed by the same event and were in equilibrium with the reservoir when they formed, they should form an isochron. This can reduce the problem of contamination. In uranium-lead dating, the concordia diagram is used which also decreases the problem of nuclide loss. Finally, correlation between different isotopic dating methods may be required to confirm the age of a sample. For example, the age of the Amitsoq gneisses from western Greenland was determined to be  using uranium-lead dating and  using lead-lead dating, results that are consistent with each other.

text: The basic equation of radiometric dating requires that neither the parent nuclide nor the daughter product can enter or leave the material after its formation. The possible confounding effects of contamination of parent and daughter isotopes have to be considered, as do the effects of any loss or gain of such isotopes since the sample was created. It is therefore essential to have as much information as possible about the material being dated and to check for possible signs of

text: alteration

text: . Precision is enhanced if measurements are taken on multiple samples from different locations of the rock body. Alternatively, if several different minerals can be dated from the same sample and are assumed to be formed by the same event and were in equilibrium with the reservoir when they formed, they should form an

text: isochron

text: . This can reduce the problem of

text: contamination

text: . In

text: uranium-lead dating

text: , the

text: concordia diagram

text: is used which also decreases the problem of nuclide loss. Finally, correlation between different isotopic dating methods may be required to confirm the age of a sample. For example, the age of the Amitsoq

text: gneiss

text: es from western

text: Greenland

text: was determined to be  using uranium-lead dating and  using lead-lead dating, results that are consistent with each other.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: uranium-lead dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the concordia diagram is used which also decreases the problem of nuclide loss

answers: NDQ_005718

answers: contamination of parent and daughter isotopes

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: multiple samples from different locations of the rock body.

answers: NDQ_005712

answers: neither the parent nuclide nor the daughter product

answers: NDQ_005713

answers: The basic equation of radiometric dating

answers: NDQ_005714

answers: contamination of parent and daughter isotopes

answers: NDQ_005715

answers: The basic equation of radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the concordia diagram

answers: NDQ_005718

answers: contamination of parent and daughter isotopes

answers: NDQ_005719

answers: lead-lead dating,

answers: NDQ_005720

answers: lead-lead dating,

text: Direct photophoresis is caused by the transfer of photon momentum to a particle by refraction and reflection. Movement of particles in the forward direction occurs when the particle is transparent and has an index of refraction larger compared to its surrounding medium. Indirect photophoresis occurs as a result of an increase in the kinetic energy of molecules when particles absorb incident light only on the irradiated side, thus creating a temperature gradient within the particle. In this situation the surrounding gas layer reaches temperature equilibrium with the surface of the particle. Molecules with higher kinetic energy in the region of higher gas temperature impinge on the particle with greater momenta than molecules in the cold region; this causes a migration of particles in a direction opposite to the surface temperature gradient. The component of the photophoretic force responsible for this phenomenon is called the radiometric force. This comes as a result of uneven distribution of radiant energy (source function within a particle).Indirect photophoretic force depends on the physical properties of the particle and the surrounding medium.

text: Direct photophoresis is caused by the transfer of photon momentum to a particle by refraction and reflection. Movement of particles in the forward direction occurs when the particle is transparent and has an

text: index of refraction

text: larger compared to its surrounding medium. Indirect photophoresis occurs as a result of an increase in the kinetic energy of molecules when particles absorb incident light only on the irradiated side, thus creating a temperature gradient within the particle. In this situation the surrounding gas layer reaches temperature equilibrium with the surface of the particle. Molecules with higher kinetic energy in the region of higher gas temperature impinge on the particle with greater momenta than molecules in the cold region; this causes a migration of particles in a direction opposite to the surface temperature gradient. The component of the photophoretic force responsible for this phenomenon is called the radiometric force. This comes as a result of uneven distribution of radiant energy (source function within a particle).Indirect photophoretic force depends on the physical properties of the particle and the surrounding medium.

answers: NDQ_005711

answers: radiometric force

answers: NDQ_005712

answers: indirect photophoresis

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: direct photophoresis

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: Indirect photophoresis

answers: NDQ_005717

answers: Indirect photophoresis occurs as a result of an increase in the kinetic energy of molecules

answers: NDQ_005718

answers: uneven distribution of radiant energy

answers: NDQ_005719

answers: are useful for very young materials

answers: NDQ_005720

answers: NDQ_005711

answers: uneven distribution of radiant energy

answers: NDQ_005712

answers: uneven distribution of radiant energy

answers: NDQ_005713

answers: radiometric force.

answers: NDQ_005714

answers: radiometric force.

answers: NDQ_005715

answers: Indirect photophoresis

answers: NDQ_005716

answers: Direct photophoresis

answers: NDQ_005717

answers: particles absorb incident light only on the irradiated side,

answers: NDQ_005718

answers: uneven distribution of radiant energy

answers: NDQ_005719

answers: Direct photophoresis

answers: NDQ_005720

answers: index of refraction larger compared to its surrounding medium.

text: Any material sample contains elements and compounds that are subject to decay into other elements and compounds. In cases where the rate of decay is predictable and the proportions of initial and end products can be known exactly, consistent dates of the artifact can be calculated. Due to the problem of sample contamination and variability of the natural proportions of the materials in the media, sample analysis in the case where verification can be checked by grand layering systems has often been found to be widely inaccurate. Chemical dates therefore are only considered reliable used in conjunction with other methods. They are collected in groups of data points that form a pattern when graphed. Isolated dates are not considered reliable.

text: Any material sample contains elements and compounds that are subject to decay into other elements and compounds. In cases where the rate of decay is predictable and the proportions of initial and end products can be known exactly, consistent dates of the artifact can be calculated. Due to the problem of sample contamination and variability of the natural proportions of the materials in the media, sample analysis in the case where verification can be checked by grand layering systems has often been found to be widely inaccurate. Chemical dates therefore are only considered reliable used in conjunction with other methods. They are collected in groups of data points that form a pattern when graphed. Isolated dates are not considered reliable.

answers: NDQ_005711

answers: decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: isolated dates are not considered reliable

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: it decay

answers: NDQ_005717

answers: chemical dates therefore are only considered reliable used in conjunction with other methods

answers: NDQ_005718

answers: chemical dates therefore are only considered reliable used in conjunction with other methods

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: the rate of decay

answers: NDQ_005712

answers: the rate of decay is predictable

answers: NDQ_005713

answers: consistent dates of the artifact can be calculated.

answers: NDQ_005714

answers: Chemical dates therefore are only considered reliable used in conjunction with other methods.

answers: NDQ_005715

answers: Isolated dates

answers: NDQ_005716

answers: Chemical dates

answers: NDQ_005717

answers: Chemical dates therefore are only considered reliable used in conjunction with other methods.

answers: NDQ_005718

answers: sample contamination and variability of the natural proportions of the materials in the media,

answers: NDQ_005719

answers: Chemical dates

answers: NDQ_005720

answers: Chemical dates

text: A number of radiocarbon dates have been published:

text: A number of

text: radiocarbon dates

text: have been published:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon is present

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: radiocarbon is a non-radioactive element

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon dates

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dates

text: Dating a specific sample of fossilized carbonaceous material is more complicated. Such deposits often contain trace amounts of carbon-14. These amounts can vary significantly between samples, ranging up to 1% of the ratio found in living organisms, a concentration comparable to an apparent age of 40,000. This may indicate possible contamination by small amounts of bacteria, underground sources of radiation causing the N(n,p) C reaction, direct uranium decay (although reported measured ratios of C/U in uranium-bearing ores would imply roughly 1 uranium atom for every two carbon atoms in order to cause the C/C ratio, measured to be on the order of 10), or other unknown secondary sources of carbon-14 production. The presence of carbon-14 in the isotopic signature of a sample of carbonaceous material possibly indicates its contamination by biogenic sources or the decay of radioactive material in surrounding geologic strata. In connection with building the Borexino solar neutrino observatory, petroleum feedstock (for synthesizing the primary scintillant) was obtained with low C content. In the Borexino Counting Test Facility, a C/C ratio of 1.94×10 was determined; probable reactions responsible for varied levels of C in different petroleum reservoirs, and the lower C levels in methane, have been discussed by Bonvicini et al.

text: Dating a specific sample of fossilized carbonaceous material is more complicated. Such deposits often contain trace amounts of carbon-14. These amounts can vary significantly between samples, ranging up to 1% of the ratio found in living organisms, a concentration comparable to an apparent age of 40,000. This may indicate possible contamination by small amounts of bacteria, underground sources of radiation causing the N(n,p) C reaction, direct uranium decay (although reported measured ratios of C/U in uranium-bearing ores would imply roughly 1 uranium atom for every two carbon atoms in order to cause the C/C ratio, measured to be on the order of 10), or other unknown secondary sources of carbon-14 production. The presence of carbon-14 in the

text: isotopic signature

text: of a sample of carbonaceous material possibly indicates its contamination by biogenic sources or the decay of radioactive material in surrounding geologic strata. In connection with building the

text: Borexino

text: solar neutrino observatory, petroleum feedstock (for synthesizing the primary scintillant) was obtained with low C content. In the Borexino Counting Test Facility, a C/C ratio of 1.94×10 was determined; probable reactions responsible for varied levels of C in different

text: petroleum reservoir

text: s, and the lower C levels in methane, have been discussed by Bonvicini et al.

answers: NDQ_005711

answers: carbon-14

answers: NDQ_005712

answers: carbon-14

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains and artifacts because

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14

answers: NDQ_005717

answers: Carbon-14 in the isotopic signature

answers: NDQ_005718

answers: These amounts can vary significantly between samples

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: carbon-14.

answers: NDQ_005712

answers: 40,000.

answers: NDQ_005713

answers: 40,000.

answers: NDQ_005714

answers: Such deposits often contain trace amounts of carbon-14.

answers: NDQ_005715

answers: 40,000.

answers: NDQ_005716

answers: 1% of the ratio found in living organisms,

answers: NDQ_005717

answers: carbon-14.

answers: NDQ_005718

answers: These amounts can vary significantly between samples,

answers: NDQ_005719

answers: 40,000.

answers: NDQ_005720

answers: 40,000.

text: An historically established date in the common calendar which corresponds to the occurrence of a key biblical event known to history is required as a starting point, drawn from reliable sources outside the Bible. (See extra-biblical sources.) Then an exhaustive knowledge of the numbers of years explicitly stated in the Scriptures and a calculator provide the detailed data. With 587 BCE as an historically established base date and counting back, a chronology of the dates of the reigns of the kings and the judges, of the date of the Exodus, the dates of all the patriarchs back to the Flood, the dates of the antediluvian patriarchs and the date of the formation of Adam in the Garden of Eden, can be stated as a literal interpretation.

text: An historically established date in the

text: common calendar

text: which

text: corresponds

text: to the occurrence of a key biblical event

text: known to history

text: is required as a starting point, drawn from

text: reliable sources

text: outside the Bible. (See

entity_name: List of biblical figures identified in extra-biblical sources

text: extra-biblical sources

text: .) Then an exhaustive knowledge of the numbers of years explicitly stated in the Scriptures and a calculator provide the detailed data. With

text: BCE

text: as an historically established base date and counting back, a chronology of the dates of the reigns of the

text: kings

text: and the

text: judges

text: , of the date of the

text: Exodus

text: , the dates of all the

text: patriarchs

text: back to the

text: Flood

text: , the dates of the

text: antediluvian

text: patriarchs and the date of the formation of

text: Adam

text: in the

text: Garden of Eden

text: , can be stated as a literal interpretation.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 587 BCE

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: 5.730

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 587 BCE as an historically established base date

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: reliable sources outside the Bible.

answers: NDQ_005712

answers: 587 BCE

answers: NDQ_005713

answers: 587 BCE

answers: NDQ_005714

answers: reliable sources outside the Bible.

answers: NDQ_005715

answers: 587 BCE

answers: NDQ_005716

answers: An historically established date in the common calendar

answers: NDQ_005717

answers: 587 BCE

answers: NDQ_005718

answers: reliable sources outside the Bible.

answers: NDQ_005719

answers: 587 BCE

answers: NDQ_005720

answers: 587 BCE

text: All experts agree that stone circles are of pre-Christian date, but beyond that stone circles have proven difficult to date accurately. Radiocarbon dating has produced a wide range of dates at different sites. This is at least partly due to an inadequacy of materials suitable for radiocarbon dating that can be reliably obtained from the sites. The diversity of radiocarbon evidence may also suggest that stone circles were constructed over a very long period, or were sometimes reconstructed at later dates. It is often not clear when building started. A further obstacle to dating is that there are generally no other archaeological artifacts associated with the stone circles. Traditional archaeological artifacts, such as pottery sherds, bones, etc., are not often found at the sites, and when found are frequently of a later date than the associated stone circle.

text: All experts agree that stone circles are of pre-Christian date, but beyond that stone circles have proven difficult to date accurately.

text: Radiocarbon dating

text: has produced a wide range of dates at different sites. This is at least partly due to an inadequacy of materials suitable for radiocarbon dating that can be reliably obtained from the sites. The diversity of radiocarbon evidence may also suggest that stone circles were constructed over a very long period, or were sometimes reconstructed at later dates. It is often not clear when building started. A further obstacle to dating is that there are generally no other archaeological artifacts associated with the stone circles. Traditional archaeological artifacts, such as pottery

text: sherd

text: s, bones, etc., are not often found at the sites, and when found are frequently of a later date than the associated stone circle.

answers: NDQ_005711

answers: Radiocarbon dating

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: inadequacy of materials

answers: NDQ_005715

answers: how long does carbon-14 decay?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon dating has produced a wide range of dates

answers: NDQ_005718

answers: there are generally no other archaeological artifacts associated with the stone circles

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: inadequacy of materials suitable for radiocarbon dating

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: inadequacy of materials suitable for radiocarbon dating

answers: NDQ_005715

answers: Radiocarbon dating

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating that can be reliably obtained from the sites.

answers: NDQ_005718

answers: there are generally no other archaeological artifacts associated with the stone circles.

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: Adventists believe that inorganic matter was created prior to the creation week and was altered into its present form during the creation week. Therefore, the computed radiometric dates of standard geology are largely irrelevant to dating the creation of life on Earth; ratios of isotopic elements reflect an ancient universe. Clyde Webster calls radiometric dating an "interpretive science" with uncertainties. He stated that "it would seem logical, almost compelling to seriously consider other sources of data for determining the time of Creation" concluding that for a Christian scientist "such a primary source is the Holy Scripture."

text: Adventists believe that inorganic matter was created prior to the creation week and was altered into its present form during the creation week. Therefore, the computed radiometric dates of standard geology are largely irrelevant to dating the creation of life on Earth; ratios of isotopic elements reflect an ancient universe. Clyde Webster calls radiometric dating an "interpretive science" with uncertainties. He stated that "it would seem logical, almost compelling to seriously consider other sources of data for determining the time of Creation" concluding that for a Christian scientist "such a primary source is the Holy Scripture."

answers: NDQ_005711

answers: isotopic elements

answers: NDQ_005712

answers: ratios of isotopic elements

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: ratios of isotopic elements reflect an ancient universe

answers: NDQ_005718

answers: uncertainties

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: ratios of isotopic elements

answers: NDQ_005712

answers: ratios of isotopic elements reflect an ancient universe.

answers: NDQ_005713

answers: Clyde Webster calls radiometric dating

answers: NDQ_005714

answers: ratios of isotopic elements reflect an ancient universe.

answers: NDQ_005715

answers: Clyde Webster calls radiometric dating

answers: NDQ_005716

answers: ratios of isotopic elements

answers: NDQ_005717

answers: ratios of isotopic elements reflect an ancient universe.

answers: NDQ_005718

answers: uncertainties.

answers: NDQ_005719

answers: ratios of isotopic elements

answers: NDQ_005720

answers: radiometric dates

text: Crookes put a tiny vaned turbine or paddlewheel in the path of the cathode rays, and found that it rotated when the rays hit it. The paddlewheel turned in a direction away from the cathode side of the tube, suggesting that the rays were coming from the cathode. Crookes concluded at the time that this showed that cathode rays had momentum, so the rays were likely matter particles.  However, later it was concluded that the paddle wheel turned not due to the momentum of the particles (or electrons) hitting the paddle wheel but due to the radiometric effect.  When the rays hit the paddle surface they heated it, and the heat caused the gas next to it to expand, pushing the paddle.  This was proven in 1903 by J. J. Thomson who calculated that the momentum of the electrons hitting the paddle wheel would only be sufficient to turn the wheel one revolution per minute.  All this experiment really showed was that cathode rays were able to heat surfaces.

text: Crookes put a tiny vaned

text: turbine

text: or

text: paddlewheel

text: in the path of the cathode rays, and found that it rotated when the rays hit it. The paddlewheel turned in a direction away from the cathode side of the tube, suggesting that the rays were coming from the cathode. Crookes concluded at the time that this showed that cathode rays had

text: momentum

text: , so the rays were likely

text: matter

text: particles.  However, later it was concluded that the paddle wheel turned not due to the momentum of the particles (or electrons) hitting the paddle wheel but due to the

text: radiometric effect

text: .  When the rays hit the paddle surface they heated it, and the heat caused the gas next to it to expand, pushing the paddle.  This was proven in 1903 by

text: J. J. Thomson

text: who calculated that the momentum of the electrons hitting the paddle wheel would only be sufficient to turn the wheel one revolution per minute.  All this experiment really showed was that cathode rays were able to heat surfaces.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: cathode

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric effect

answers: NDQ_005717

answers: When the rays hit the paddle surface they heated it

answers: NDQ_005718

answers: cathode rays were able to heat surfaces

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: cathode rays,

answers: NDQ_005712

answers: cathode rays,

answers: NDQ_005713

answers: radiometric effect.

answers: NDQ_005714

answers: cathode rays,

answers: NDQ_005715

answers: radiometric effect.

answers: NDQ_005716

answers: cathode rays,

answers: NDQ_005717

answers: cathode rays,

answers: NDQ_005718

answers: one revolution per minute.

answers: NDQ_005719

answers: cathode rays,

answers: NDQ_005720

answers: radiometric effect.

text: Based on calculations of Earth's cooling rate, which assumed constant conductivity in the Earth's interior, in 1862 Lord Kelvin (William Thomson) estimated the age of the Earth at 98 million years, in contrast to the age of 4.5 billion years obtained by radiometric dating. As pointed out by John Perry in 1895 a variable conductivity in the Earth's interior could expand the computed age of the Earth to billions of years, as later confirmed by radiometric dating. Contrary to the usual representation of Kelvin's argument, the observed thermal gradient of the Earth's crust would not be explained by the addition of radioactivity as a heat source. More significantly, mantle convection alters how heat is transported within the Earth, invalidating Kelvin's assumption of purely conductive cooling.

text: Based on calculations of Earth's cooling rate, which assumed constant conductivity in the Earth's interior, in 1862

text: Lord Kelvin

text: (William Thomson) estimated the age of the Earth at 98 million years, in contrast to the age of 4.5 billion years obtained by

text: radiometric dating

text: . As pointed out by John Perry in 1895 a variable conductivity in the Earth's interior could expand the computed age of the Earth to billions of years, as later confirmed by radiometric dating. Contrary to the usual representation of Kelvin's argument, the observed thermal gradient of the Earth's crust would not be explained by the addition of radioactivity as a heat source. More significantly,

text: mantle convection

text: alters how heat is transported within the Earth, invalidating Kelvin's assumption of purely conductive cooling.

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: variable conductivity

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the age of 4.5 billion years

answers: NDQ_005718

answers: variable conductivity in the Earth's interior

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiometric dating.

answers: NDQ_005712

answers: variable conductivity

answers: NDQ_005713

answers: 4.5 billion years obtained by radiometric dating.

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: 98 million years,

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: a variable conductivity

answers: NDQ_005718

answers: mantle convection alters how heat is transported within the Earth,

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: Radiometric dating (Rb-Sr) indicates the Guilford Quartz Monzonite is 425 Ma (Silurian). However, A. A. Drake argued that the Guilford is of Ordovician age because it is probably comagmatic with the Woodstock Quartz Monzonite dated at 444 Ma.  One other source gives the date of 420 +/-50 Ma.

text: Radiometric dating (

text: Rb-Sr

text: ) indicates the Guilford Quartz Monzonite is 425 Ma (

text: Silurian

text: ). However, A. A. Drake argued that the Guilford is of

text: Ordovician

text: age because it is probably comagmatic with the

text: Woodstock Quartz Monzonite

text: dated at 444 Ma.  One other source gives the date of 420 +/-50 Ma.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Ordovician

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Rb-Sr

answers: NDQ_005718

answers: date of 420 +/-50 Ma

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: (Rb-Sr)

answers: NDQ_005712

answers: (Silurian).

answers: NDQ_005713

answers: 420 +/-50 Ma.

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: 420

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: 420 +/-50 Ma.

answers: NDQ_005718

answers: comagmatic

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: In refutation of young Earth claims of inconstant decay-rates affecting the reliability of radiometric dating, Roger C. Wiens, a physicist specialising in isotope dating states:

text: In refutation of young Earth claims of inconstant decay-rates affecting the reliability of radiometric dating, Roger C. Wiens, a physicist specialising in isotope dating states:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: decay-rates are constant

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays at a constant rate

answers: NDQ_005715

answers: isotope dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: isotope

answers: NDQ_005718

answers: constant decay-rates

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: decay-rates

answers: NDQ_005712

answers: young Earth claims of inconstant decay-rates

answers: NDQ_005713

answers: inconstant decay-rates

answers: NDQ_005714

answers: inconstant decay-rates affecting the reliability of radiometric dating,

answers: NDQ_005715

answers: inconstant decay-rates

answers: NDQ_005716

answers: radiometric dating,

answers: NDQ_005717

answers: inconstant decay-rates

answers: NDQ_005718

answers: inconstant decay-rates

answers: NDQ_005719

answers: inconstant decay-rates affecting the reliability of radiometric dating,

answers: NDQ_005720

answers: radiometric dating,

text: If a material that selectively rejects the daughter nuclide is heated, any daughter nuclides that have been accumulated over time will be lost through diffusion, setting the isotopic "clock" to zero. The temperature at which this happens is known as the closure temperature or blocking temperature and is specific to a particular material and isotopic system. These temperatures are experimentally determined in the lab by artificially resetting sample minerals using a high-temperature furnace. As the mineral cools, the crystal structure begins to form and diffusion of isotopes is less easy. At a certain temperature, the crystal structure has formed sufficiently to prevent diffusion of isotopes. This temperature is what is known as closure temperature and represents the temperature below which the mineral is a closed system to isotopes. Thus an igneous or metamorphic rock or melt, which is slowly cooling, does not begin to exhibit measurable radioactive decay until it cools below the closure temperature. The age that can be calculated by radiometric dating is thus the time at which the rock or mineral cooled to closure temperature. Dating of different minerals and/or isotope systems (with differing closure temperatures) within the same rock can therefore enable the tracking of the thermal history of the rock in question with time, and thus the history of metamorphic events may become known in detail. This field is known as thermochronology or thermochronometry.

text: If a material that selectively rejects the daughter nuclide is heated, any daughter nuclides that have been accumulated over time will be lost through

text: diffusion

text: , setting the isotopic "clock" to zero. The temperature at which this happens is known as the

text: closure temperature

text: or blocking temperature and is specific to a particular material and isotopic system. These temperatures are experimentally determined in the lab by

text: artificially resetting sample minerals

text: using a high-temperature furnace. As the mineral cools, the crystal structure begins to form and diffusion of isotopes is less easy. At a certain temperature, the crystal structure has formed sufficiently to prevent diffusion of isotopes. This temperature is what is known as closure temperature and represents the temperature below which the mineral is a closed system to isotopes. Thus an igneous or metamorphic rock or melt, which is slowly cooling, does not begin to exhibit measurable radioactive decay until it cools below the closure temperature. The age that can be calculated by radiometric dating is thus the time at which the rock or mineral cooled to closure temperature. Dating of different minerals and/or isotope systems (with differing closure temperatures) within the same rock can therefore enable the tracking of the thermal history of the rock in question with time, and thus the history of metamorphic events may become known in detail. This field is known as

text: thermochronology

text: or thermochronometry.

answers: NDQ_005711

answers: time at which the rock or mineral cooled

answers: NDQ_005712

answers: the rock or mineral cooled to closure temperature

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating is thus the time

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radioactive decay occur

answers: NDQ_005717

answers: the crystal structure has formed sufficiently to prevent diffusion of isotopes

answers: NDQ_005718

answers: does not begin to exhibit measurable radioactive decay until it cools below the closure temperature

answers: NDQ_005719

answers: What field is thermochronology or thermochronology?

answers: NDQ_005720

answers: NDQ_005711

answers: the time at which the rock or mineral cooled to closure temperature.

answers: NDQ_005712

answers: the time at which the rock or mineral cooled to closure temperature.

answers: NDQ_005713

answers: the time at which the rock or mineral cooled to closure temperature.

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: closure temperature

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: measurable radioactive decay until it cools below the closure temperature.

answers: NDQ_005718

answers: diffusion of isotopes is less easy.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Raytheon has patented a number of weapon designs which allow for the use of depleted uranium. For instance there is the patent "Missile warhead design" (1997) which suggests the use of tungsten but adds that "In addition, other ballast sizes and other materials such as lead or depleted uranium may be used without departing from the scope of the present invention". There is also the patent "Guided kinetic penetrator" (2005) which patents "9. The projectile guidance system of claim 1, wherein the kinetic penetrator body comprises at least one of tungsten, carbide steel, and depleted uranium". The patent "Improved missile warhead design" (1998) which patents "2. The invention of Claim 1 wherein the ballast mechanism (16) includes tungsten, lead and/or depleted uranium material(s)", the "Cluster explosively-formed penetrator warheads" patent (2011) which patents "The spherically-shaped explosive device of claim 1, wherein each of the plurality of liners comprises a material selected from a group consisting of copper, molybdenum, tungsten, aluminum, tantalum, depleted uranium, lead, tin, cadmium, cobalt, magnesium, titanium, zinc, zirconium, beryllium, nickel, silver, and combinations thereof", and the "Low-collateral damage directed fragmentation munition" patent (2014) which uses a tungsten or uranium ring ("The ring 44 may be made of tungsten or depleted uranium, to give non-limiting examples") to direct the energy of the weapon.

text: Raytheon has patented a number of weapon designs which allow for the use of

text: depleted uranium

text: Low-collateral damage directed fragmentation

text: munition" patent (2014) which uses a tungsten or uranium ring ("The ring 44 may be made of tungsten or depleted uranium, to give non-limiting examples") to direct the energy of the weapon.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: depleted uranium

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: depleted uranium

answers: NDQ_005718

answers: non-limiting examples

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: depleted uranium,

answers: NDQ_005712

answers: depleted uranium,

answers: NDQ_005713

answers: depleted uranium,

answers: NDQ_005714

answers: depleted uranium,

answers: NDQ_005715

answers: depleted uranium,

answers: NDQ_005716

answers: depleted uranium,

answers: NDQ_005717

answers: depleted uranium,

answers: NDQ_005718

answers: depleted uranium,

answers: NDQ_005719

answers: depleted uranium,

answers: NDQ_005720

answers: depleted uranium,

text: The calculations given above produce dates in radiocarbon years: i.e. dates that represent the age the sample would be if the / ratio had been constant historically. Although Libby had pointed out as early as 1955 the possibility that this assumption was incorrect, it was not until discrepancies began to accumulate between measured ages and known historical dates for artefacts that it became clear that a correction would need to be applied to radiocarbon ages to obtain calendar dates.

text: The calculations given above produce dates in radiocarbon years: i.e. dates that represent the age the sample would be if the / ratio had been constant historically. Although Libby had pointed out as early as 1955 the possibility that this assumption was incorrect, it was not until discrepancies began to accumulate between measured ages and known historical dates for artefacts that it became clear that a correction would need to be applied to radiocarbon ages to obtain calendar dates.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: 5,730 years

answers: NDQ_005716

answers: radiocarbon years

answers: NDQ_005717

answers: radiocarbon years

answers: NDQ_005718

answers: correction would need to be applied to radiocarbon ages

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: if the / ratio had been constant historically.

answers: NDQ_005712

answers: radiocarbon years:

answers: NDQ_005713

answers: radiocarbon years:

answers: NDQ_005714

answers: radiocarbon years:

answers: NDQ_005715

answers: radiocarbon years:

answers: NDQ_005716

answers: radiocarbon years:

answers: NDQ_005717

answers: radiocarbon years:

answers: NDQ_005718

answers: discrepancies began to accumulate between measured ages and known historical dates

answers: NDQ_005719

answers: radiocarbon years:

answers: NDQ_005720

answers: radiocarbon years:

text: According to controversial radiocarbon dates, Corded Ware ceramic forms in single graves develop earlier in the area that is now Poland than in western and southern Central Europe. The earliest radiocarbon dates for Corded Ware indeed come from Kujawy and Lesser Poland in central and southern Poland and point to the period around 3000 BCE. However, subsequent  review has challenged this perspective, instead pointing out that the wide variation in dating of the Corded Ware, especially the dating of the culture's beginning, is based on individual outlier graves, is not particularly in line with other archaeological data and runs afoul of plateaus in the radiocarbon calibration curve; in the one case where the dating can be clarified with dendrochronology, in Switzerland, Corded Ware is found for only a short period from 2750 BCE to 2400 BCE.Furthermore, because the short period in Switzerland seems to represent examples of artifacts from all the major sub-periods of the Corded Ware culture elsewhere, some researchers conclude that Corded Ware occurred more or less simultaneously throughout North Central Europe in the early 2900 BCE, in a number of "centers" which subsequently formed their own local networks. Carbon-14 dating of the remaining central European regions shows that Corded Ware appeared after 2880 BCE According to this theory, it spread to the Lüneburg Heath and then further to the North European Plain, Rhineland, Switzerland, Scandinavia, the Baltic region and Russia to Moscow, where the culture met with the pastoralists considered indigenous to the steppes. However, the theories that hypothesize an origin of the Corded Ware phenomenon based on continuity with preceding cultures of Western or Central Europe run afoul of newer palaeogenomic data showing that the Corded Ware population had an ancestry derived at least 75% from the Yamnaya population of the steppes.

text: According to controversial radiocarbon dates, Corded Ware ceramic forms in single graves develop earlier in the area that is now Poland than in western and southern Central Europe. The earliest radiocarbon dates for Corded Ware indeed come from

text: Kujawy

text: and

text: Lesser Poland

text: in central and southern Poland and point to the period around 3000 BCE. However, subsequent  review has challenged this perspective, instead pointing out that the wide variation in dating of the Corded Ware, especially the dating of the culture's beginning, is based on individual outlier graves, is not particularly in line with other archaeological data and runs afoul of plateaus in the

text: radiocarbon calibration curve

text: ; in the one case where the dating can be clarified with dendrochronology, in Switzerland, Corded Ware is found for only a short period from 2750 BCE to 2400 BCE.Furthermore, because the short period in Switzerland seems to represent examples of artifacts from all the major sub-periods of the Corded Ware culture elsewhere, some researchers conclude that Corded Ware occurred more or less simultaneously throughout North Central Europe in the early 2900 BCE, in a number of "centers" which subsequently formed their own local networks. Carbon-14 dating of the remaining central European regions shows that Corded Ware appeared after 2880 BCE According to this theory, it spread to the

text: Lüneburg Heath

text: and then further to the North European Plain, Rhineland, Switzerland, Scandinavia, the Baltic region and Russia to Moscow, where the culture met with the pastoralists considered indigenous to the steppes. However, the theories that hypothesize an origin of the Corded Ware phenomenon based on continuity with preceding cultures of Western or Central Europe run afoul of newer

text: palaeogenomic data

text: showing that the Corded Ware population had an ancestry derived at least 75% from the

text: Yamnaya

text: population of the steppes.

answers: NDQ_005711

answers: Carbon-14

answers: NDQ_005712

answers: Carbon-14 dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: NDQ_005716

answers: Carbon-14 dating

answers: NDQ_005717

answers: Carbon-14

answers: NDQ_005718

answers: plateaus in the radiocarbon calibration curve

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Carbon-14

answers: NDQ_005712

answers: Carbon-14

answers: NDQ_005713

answers: Carbon-14 dating

answers: NDQ_005714

answers: Carbon-14 dating

answers: NDQ_005715

answers: Carbon-14

answers: NDQ_005716

answers: Carbon-14 dating

answers: NDQ_005717

answers: Corded Ware appeared after 2880 BCE

answers: NDQ_005718

answers: newer palaeogenomic data

answers: NDQ_005719

answers: Carbon-14 dating

answers: NDQ_005720

answers: Carbon-14 dating

text: Uranium-lead radiometric dating involves using Uranium-235 or Uranium-238 to date a substance's absolute age. This scheme has been refined to the point that the error margin in dates of rocks can be as low as less than two million years in two-and-a-half billion years. An error margin of 2–5% has been achieved on younger Mesozoic rocks.

text: Uranium-lead radiometric dating

text: involves using Uranium-235 or Uranium-238 to date a substance's absolute age. This scheme has been refined to the point that the error margin in dates of rocks can be as low as less than two million years in two-and-a-half billion years. An error margin of 2–5% has been achieved on younger

text: Mesozoic

text: rocks.

answers: NDQ_005711

answers: Uranium

answers: NDQ_005712

answers: An error margin of 2–5% has been achieved on younger Mesozoic rocks

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Uranium-lead radiometric dating involves using Uranium-235 or Uranium-238

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: An error margin of 2–5% has been achieved on younger Mesozoic rocks.

answers: NDQ_005718

answers: error margin

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: absolute age.

answers: NDQ_005712

answers: absolute age.

answers: NDQ_005713

answers: Uranium-235 or Uranium-238

answers: NDQ_005714

answers: Uranium-lead radiometric dating

answers: NDQ_005715

answers: Uranium-lead radiometric dating

answers: NDQ_005716

answers: Uranium-lead radiometric dating

answers: NDQ_005717

answers: Uranium-235 or Uranium-238

answers: NDQ_005718

answers: error margin

answers: NDQ_005719

answers: An error margin of 2–5%

answers: NDQ_005720

answers: two million years in two-and-a-half billion years.

text: Radiometric methods can be used to date different stages of the history of a meteorite. Condensation from the solar nebula is recorded by calcium-aluminium-rich inclusions and chondrules. These can be dated by using radionuclides that were present in the solar nebula (e.g. Al/Mg, Mn/Cr, U/Pb, I/Xe). After the condensed material accretes to planetesimals of sufficient size melting and differentiation take place. These processes can be dated with the U/Pb, Rb/Sr, Sm/Nd and  Lu/Hf methods. Metallic core formation and cooling can be dated by applying the Re/Os method to iron meteorites. Large scale impact events or even the destruction of the parent body can be dated using the Ar/Ar method and the Pu fission track method. After breakup of the parent body meteoroids are exposed to cosmic radiation. The length of this exposure can be dated using the H/He method, Na/Ne, Kr/Kr. After impact on earth (or any other planet with sufficient cosmic ray shielding) cosmogenic radionuclides decay and can be used to date the time since the meteorite fell. Methods to date this terrestrial exposure are Cl, C, Kr.

text: Radiometric methods can be used to date different stages of the history of a meteorite. Condensation from the

entity_name: Formation and evolution of the Solar System

text: solar nebula

text: is recorded by

text: calcium-aluminium-rich inclusion

text: s and

text: chondrules

text: . These can be dated by using radionuclides that were present in the solar nebula (e.g.

text: Al/Mg

text: , Mn/Cr,

text: U/Pb

text: I/Xe

text: ). After the condensed material accretes to

text: planetesimal

text: s of sufficient size melting and differentiation take place. These processes can be dated with the

text: U/Pb

text: Rb/Sr

text: Sm/Nd

text: and

text: Lu/Hf

text: methods. Metallic core formation and cooling can be dated by applying the

text: Re/Os method

text: to

text: iron meteorite

text: s. Large scale impact events or even the destruction of the parent body can be dated using the

text: Ar/Ar method

text: and the

text: Pu fission track method

text: . After breakup of the parent body meteoroids are exposed to cosmic radiation. The length of this exposure can be dated using the

text: H/He method

text: , Na/Ne, Kr/Kr. After impact on earth (or any other planet with sufficient cosmic ray shielding) cosmogenic radionuclides decay and can be used to date the time since the meteorite fell. Methods to date this terrestrial exposure are

text: Cl

text: C

text: , Kr.

answers: NDQ_005711

answers: using radionuclides

answers: NDQ_005712

answers: meteorites

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: nuclear decay

answers: NDQ_005717

answers: the Pu fission track method

answers: NDQ_005718

answers: time since the meteorite fell

answers: NDQ_005719

answers: How old is a meteorite?

answers: NDQ_005720

answers: NDQ_005711

answers: radionuclides

answers: NDQ_005712

answers: sufficient size

answers: NDQ_005713

answers: radionuclides

answers: NDQ_005714

answers: radionuclides

answers: NDQ_005715

answers: cosmogenic radionuclides

answers: NDQ_005716

answers: cosmogenic radionuclides decay

answers: NDQ_005717

answers: H/He method, Na/Ne, Kr/Kr.

answers: NDQ_005718

answers: radionuclides

answers: NDQ_005719

answers: radionuclides

answers: NDQ_005720

answers: radionuclides

text: Magmas erupted from the Erebus hotspot are similar to those erupted from hotspots at the active East African Rift in eastern Africa. Mount Bird at the northernmost end of Ross Island and Mount Terror at its eastern end are large basaltic shield volcanoes that have been potassium-argon dated to be 3.8–4.8 and 0.8–1.8 million years old.

text: Magma

text: s erupted from the Erebus hotspot are similar to those erupted from hotspots at the active

text: East African Rift

text: in eastern

text: Africa

text: Mount Bird

text: at the northernmost end of Ross Island and

text: Mount Terror

text: at its eastern end are large

text: basalt

text: ic

text: shield volcano

text: es that have been

text: potassium-argon dated

text: to be 3.8–4.8 and 0.8–1.8 million years old.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 3.8–4.8

answers: NDQ_005718

answers: potassium-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 3.8–4.8 and 0.8–1.8 million years old.

answers: NDQ_005713

answers: 3.8–4.8 and 0.8–1.8 million years old.

answers: NDQ_005714

answers: 3.8–4.8 and 0.8–1.8 million years old.

answers: NDQ_005715

answers: 3.8–4.8

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 3.8–4.8 and 0.8–1.8 million years old.

answers: NDQ_005718

answers: 0.8–1.8 million years old.

answers: NDQ_005719

answers: 0.8–1.8 million years old.

answers: NDQ_005720

answers: 3.8–4.8

text: Stage 10 of the Cambrian is the still unnamed third and final stage of the Furongian Series. It follows the Jiangshanian and precedes the Ordovician Tremadocian Stage. The proposed lower boundary is the first appearance of the trilobite Lotagnostus americanus around  million years ago, but other fossils are also being discussed (see below). The upper boundary is defined as the appearance of the conodont Iapetognathus fluctivagus which marks the beginning of the Tremadocian and is radiometrically dated as  million years ago.

text: Stage 10 of the Cambrian is the still unnamed third and final stage of the

text: Furongian

text: Series. It follows the

text: Jiangshanian

text: and precedes the Ordovician

text: Tremadocian

text: Stage. The proposed lower boundary is the first appearance of the trilobite

text: Lotagnostus americanus

text: around  million years ago, but other fossils are also being discussed (

text: see below

text: ). The upper boundary is defined as the appearance of the

text: conodont

text: Iapetognathus fluctivagus

text: which marks the beginning of the

text: Tremadocian

text: and is radiometrically dated as  million years ago.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Tremadocian

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating is used

answers: NDQ_005715

answers: radiometrically dated as million years ago

answers: NDQ_005716

answers: radiometrically date

answers: NDQ_005717

answers: is radiometrically dated as million years ago

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: What is the upper boundary defined as

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: million years ago.

answers: NDQ_005712

answers: million years ago.

answers: NDQ_005713

answers: million years ago.

answers: NDQ_005714

answers: radiometrically dated

answers: NDQ_005715

answers: Stage 10 of the Cambrian

answers: NDQ_005716

answers: radiometrically dated

answers: NDQ_005717

answers: radiometrically dated as million years ago.

answers: NDQ_005718

answers: fossils

answers: NDQ_005719

answers: radiometrically dated as million years ago.

answers: NDQ_005720

answers: radiometrically dated

text: Argon, a noble gas, is not commonly incorporated into such samples except when produced in situ through radioactive decay. The date measured reveals the last time that the object was heated past the closure temperature at which the trapped argon can escape the lattice. K-Ar dating was used to calibrate the geomagnetic polarity time scale.

text: Argon

text: , a noble gas, is not commonly incorporated into such samples except when produced in situ through radioactive decay. The date measured reveals the last time that the object was heated past the

text: closure temperature

text: at which the trapped argon can escape the lattice. K-Ar dating was used to calibrate the

text: geomagnetic polarity time scale

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: K-Ar dating

answers: NDQ_005715

answers: NDQ_005716

answers: K-Ar dating

answers: NDQ_005717

answers: K-Ar dating was used to calibrate the geomagnetic polarity time scale.

answers: NDQ_005718

answers: Argon, a noble gas, is not commonly incorporated into such samples

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactive decay.

answers: NDQ_005712

answers: produced in situ through radioactive decay.

answers: NDQ_005713

answers: radioactive decay.

answers: NDQ_005714

answers: reveals the last time that the object was heated past the closure temperature

answers: NDQ_005715

answers: K-Ar dating

answers: NDQ_005716

answers: the trapped argon can escape the lattice.

answers: NDQ_005717

answers: to calibrate the geomagnetic polarity time scale.

answers: NDQ_005718

answers: reveals the last time that the object was heated past the closure temperature

answers: NDQ_005719

answers: K-Ar dating

answers: NDQ_005720

answers: K-Ar dating

text: Holmes was a pioneer of geochronology, and performed the first accurate uranium-lead radiometric dating (specifically designed to measure the age of a rock) while an undergraduate in London, assigning an age of 370 Ma to a Devonian rock from Norway, improving on the work of Boltwood who published nothing more on the subject. This result was published in 1911, after his graduation in 1910.

text: Holmes was a pioneer of

text: geochronology

text: , and performed the first accurate

text: uranium-lead

text: radiometric dating

text: (specifically designed to measure the age of a rock) while an undergraduate in London, assigning an age of 370

text: Ma

text: to a

text: Devonian

text: rock from

text: Norway

text: , improving on the work of

text: Boltwood

text: who published nothing more on the subject. This result was published in 1911, after his graduation in 1910.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Devonian

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: isotope

answers: NDQ_005718

answers: the age of a rock

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead

answers: NDQ_005712

answers: (specifically designed to measure the age of a rock)

answers: NDQ_005713

answers: uranium-lead radiometric dating

answers: NDQ_005714

answers: uranium-lead radiometric dating

answers: NDQ_005715

answers: 1911,

answers: NDQ_005716

answers: age of a rock)

answers: NDQ_005717

answers: uranium-lead radiometric dating

answers: NDQ_005718

answers: published nothing more on the subject.

answers: NDQ_005719

answers: uranium-lead radiometric dating

answers: NDQ_005720

answers: 370

text: Thorium is not soluble in natural waters under conditions found at or near the surface of the earth, so materials grown in or from these waters do not usually contain thorium.  In contrast, uranium is soluble to some extent in all natural waters, so any material that precipitates or is grown from such waters also contains trace uranium, typically at levels of between a few parts per billion and few parts per million by weight.  As time passes after the formation of such a material, uranium-234 in the sample, with a half-life of 245,000 years, decays to thorium-230.  Thorium-230 is itself radioactive with a half-life of 75,000 years, so instead of accumulating indefinitely (as for instance is the case for the uranium-lead system), thorium-230 instead approaches secular equilibrium with its radioactive parent uranium-234.  At secular equilibrium, the number of thorium-230 decays per year within a sample is equal to the number of thorium-230 produced, which also equals the number of uranium-234 decays per year in the same sample.

text: Thorium

text: is not soluble in natural waters under conditions found at or near the surface of the earth, so materials grown in or from these waters do not usually contain thorium.  In contrast,

text: uranium

text: is soluble to some extent in all

text: natural

text: water

text: s, so any material that

text: precipitates

text: or is grown from such waters also contains trace uranium, typically at levels of between a few parts per billion and few

text: parts per million

text: by weight.  As time passes after the formation of such a material, uranium-234 in the sample, with a

text: half-life

text: of 245,000 years, decays to thorium-230.  Thorium-230 is itself radioactive with a

text: half-life

text: of 75,000 years, so instead of accumulating indefinitely (as for instance is the case for the

text: uranium-lead

text: system), thorium-230 instead approaches

text: secular equilibrium

text: with its radioactive parent uranium-234.  At

text: secular equilibrium

text: , the number of thorium-230 decays per year within a sample is equal to the number of thorium-230 produced, which also equals the number of uranium-234 decays per year in the same sample.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: NDQ_005714

answers: half-life of 245,000 years

answers: NDQ_005715

answers: NDQ_005716

answers: uranium-234

answers: NDQ_005717

answers: At secular equilibrium, the number of thorium-230 decays per year within a sample is equal to the number of thorium-230 produced

answers: NDQ_005718

answers: half-life of 245,000 years

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: half-life of 245,000 years,

answers: NDQ_005712

answers: 75,000 years,

answers: NDQ_005713

answers: thorium-230.

answers: NDQ_005714

answers: Thorium is not soluble in natural waters

answers: NDQ_005715

answers: thorium-230.

answers: NDQ_005716

answers: decays to thorium-230.

answers: NDQ_005717

answers: thorium-230.

answers: NDQ_005718

answers: accumulating indefinitely

answers: NDQ_005719

answers: thorium-230.

answers: NDQ_005720

answers: thorium-230.

text: Camelomecia is known from three total adult fossils, the holotype, specimen number "AMNH Bu-TJ003", and two additional fragmentary adults not designated as paratypes.  At the time of the genus description, the three specimens were residing in the American Museum of Natural History, in New York City.  The described specimens are of queen and drone caste adults which have been preserved as inclusions in transparent chunks of Burmese amber.  The amber specimens were recovered from deposits in Kachin State, in Myanmar.  Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the Aptian – Cenomanian boundary, in the earliest Cenomanian.

text: Camelomecia is known from three total adult fossils, the

text: holotype

text: , specimen number "AMNH Bu-TJ003", and two additional fragmentary adults not designated as paratypes.  At the time of the genus description, the three specimens were residing in the

text: American Museum of Natural History

text: , in

text: New York City

text: .  The described specimens are of

text: queen and drone caste

text: adults which have been preserved as

text: inclusions

text: in transparent chunks of

text: Burmese amber

text: .  The

text: amber

text: specimens were recovered from deposits in

text: Kachin State

text: , in Myanmar.  Burmese amber has been

text: radiometrically dated

text: using

text: U

text: Pb

text: isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the

text: Aptian

text: Cenomanian

text: boundary, in the earliest Cenomanian.

answers: NDQ_005711

answers: using U-Pb isotopes

answers: NDQ_005712

answers: U-Pb isotopes

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: U-Pb isotopes

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: radiometrically dated using U-Pb isotopes

answers: NDQ_005718

answers: U-Pb isotopes

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: U-Pb isotopes,

answers: NDQ_005712

answers: U-Pb isotopes,

answers: NDQ_005713

answers: U-Pb isotopes,

answers: NDQ_005714

answers: U-Pb isotopes,

answers: NDQ_005715

answers: U-Pb isotopes,

answers: NDQ_005716

answers: radiometrically dated using U-Pb isotopes,

answers: NDQ_005717

answers: U-Pb isotopes,

answers: NDQ_005718

answers: U-Pb isotopes,

answers: NDQ_005719

answers: U-Pb isotopes,

answers: NDQ_005720

answers: U-Pb isotopes,

text: Lead-lead dating is a method for dating geological samples, normally based on 'whole-rock' samples of material such as granite. For most dating requirements it has been superseded by uranium-lead dating (U-Pb dating), but in certain specialized situations (such as dating meteorites and the age of the Earth) it is more important than U-Pb dating.

text: Lead-lead dating is a

text: method for dating

text: geological samples, normally based on 'whole-rock' samples of material such as granite. For most dating requirements it has been superseded by

text: uranium-lead dating

text: (U-Pb dating), but in certain specialized situations (such as dating meteorites and the

text: age of the Earth

text: ) it is more important than U-Pb dating.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: lead-lead

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: lead-lead dating

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: lead-lead

answers: NDQ_005718

answers: lead-lead dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 'whole-rock' samples

answers: NDQ_005712

answers: meteorites and the age of the Earth)

answers: NDQ_005713

answers: uranium-lead dating (U-Pb dating),

answers: NDQ_005714

answers: it is more important than U-Pb dating.

answers: NDQ_005715

answers: Lead-lead dating

answers: NDQ_005716

answers: Lead-lead dating is a method for dating geological samples,

answers: NDQ_005717

answers: U-Pb dating.

answers: NDQ_005718

answers: 'whole-rock' samples

answers: NDQ_005719

answers: Lead-lead dating

answers: NDQ_005720

answers: (U-Pb dating),

text: This is based on the beta decay of rubidium-87 to strontium-87, with a half-life of 50 billion years. This scheme is used to date old igneous and metamorphic rocks, and has also been used to date lunar samples. Closure temperatures are so high that they are not a concern. Rubidium-strontium dating is not as precise as the uranium-lead method, with errors of 30 to 50 million years for a 3-billion-year-old sample.

text: This is based on the beta decay of

text: rubidium

text: -87 to

text: strontium

text: -87, with a half-life of 50 billion years. This scheme is used to date old

text: igneous

text: and

text: metamorphic rocks

text: , and has also been used to date

text: lunar samples

text: . Closure temperatures are so high that they are not a concern. Rubidium-strontium dating is not as precise as the uranium-lead method, with errors of 30 to 50 million years for a 3-billion-year-old sample.

answers: NDQ_005711

answers: beta decay

answers: NDQ_005712

answers: uranium-lead

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: rubidium-strontium dating

answers: NDQ_005715

answers: NDQ_005716

answers: beta decay

answers: NDQ_005717

answers: rubidium-87 to strontium-87, with a half-life of 50 billion years

answers: NDQ_005718

answers: errors of 30 to 50 million years for a 3-billion-year-old sample

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: beta decay of rubidium-87 to strontium-87,

answers: NDQ_005712

answers: old igneous and metamorphic rocks,

answers: NDQ_005713

answers: rubidium-87 to strontium-87,

answers: NDQ_005714

answers: rubidium-87 to strontium-87,

answers: NDQ_005715

answers: rubidium-87 to strontium-87,

answers: NDQ_005716

answers: beta decay of rubidium-87 to strontium-87,

answers: NDQ_005717

answers: beta decay of rubidium-87 to strontium-87,

answers: NDQ_005718

answers: not as precise as the uranium-lead method,

answers: NDQ_005719

answers: Rubidium-strontium

answers: NDQ_005720

answers: Rubidium-strontium

text: Radioactive decay accounts for about  of the Earth's internal heat, powering the geodynamo and plate tectonics. The main heat-producing isotopes are potassium-40, uranium-238, uranium-235, and thorium-232.Radioactive elements are used for radiometric dating, the primary method for establishing an absolute time scale in geochronology.Unstable isotopes decay at predictable rates, and the decay rates of different isotopes cover several orders of magnitude, so radioactive decay can be used to accurately date both recent events and events in past geologic eras. Radiometric mapping using ground and airborne gamma spectrometry can be used to map the concentration and distribution of radioisotopes near the Earth's surface, which is useful for mapping lithology and alteration.

text: Radioactive decay

text: accounts for about  of the Earth's

text: internal heat

text: , powering the

text: geodynamo

text: and

text: plate tectonics

text: . The main heat-producing

text: isotopes

text: are

text: , uranium-235, and

text: .Radioactive elements are used for

text: radiometric dating

text: , the primary method for establishing an absolute time scale in

text: geochronology

text: .Unstable

text: isotopes

text: decay at predictable rates, and the decay rates of different isotopes cover several orders of magnitude, so radioactive decay can be used to accurately date both recent events and events in past

text: geologic eras

text: . Radiometric mapping using ground and airborne

text: gamma spectrometry

text: can be used to map the concentration and distribution of radioisotopes near the Earth's surface, which is useful for mapping lithology and alteration.

answers: NDQ_005711

answers: Radioactive elements

answers: NDQ_005712

answers: unstable isotopes decay at predictable rates

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays at predictable rates

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: Radioactive elements are used for radiometric dating

answers: NDQ_005718

answers: unstable isotopes decay at predictable rates

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: thorium-232.Radioactive elements

answers: NDQ_005712

answers: past geologic eras.

answers: NDQ_005713

answers: geochronology.Unstable isotopes decay at predictable rates,

answers: NDQ_005714

answers: geochronology.Unstable isotopes decay at predictable rates,

answers: NDQ_005715

answers: Radioactive decay accounts for about of the Earth's internal heat,

answers: NDQ_005716

answers: Radioactive decay

answers: NDQ_005717

answers: potassium-40,

answers: NDQ_005718

answers: geochronology.Unstable isotopes decay at predictable rates,

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: radiometric dating,

text: The radiometric age for the quartz diorite at Cerro Paine is 12 ± 2 million years by the rubidium-strontium method and 13 ± 1 million years by the potassium-argon method. More precise ages of 12.59 ± 0.02 and 12.50 ± 0.02 million years for the earliest and latest identified phases of the intrusion, respectively, were achieved using U/Pb methods on single zircon crystals. Basal gabbro and diorite were dated by a similar technique to 12.472 ± 0.009 to 12.431 ± 0.006 million years. Thus, magma was intruded and crystallized over 162 ± 11 thousand years. High resolution dating and excellent 3-D exposure of the laccolith and its vertical feeding system allow detailed reconstruction of the Torres del Paine fossil magma chamber history.

text: The radiometric age for the quartz diorite at Cerro Paine is 12 ± 2 million years by the rubidium-strontium method and 13 ± 1 million years by the potassium-argon method. More precise ages of 12.59 ± 0.02 and 12.50 ± 0.02 million years for the earliest and latest identified phases of the intrusion, respectively, were achieved using U/Pb methods on single zircon crystals. Basal gabbro and diorite were dated by a similar technique to 12.472 ± 0.009 to 12.431 ± 0.006 million years. Thus, magma was intruded and crystallized over 162 ± 11 thousand years. High resolution dating and excellent 3-D exposure of the

text: laccolith

text: and its vertical feeding system allow detailed reconstruction of the Torres del Paine fossil

text: magma chamber

text: history.

answers: NDQ_005711

answers: rubidium-strontium

answers: NDQ_005712

answers: rubidium-strontium method

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: rubidium-strontium

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric age

answers: NDQ_005717

answers: 13  1 million years

answers: NDQ_005718

answers: High resolution dating

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: rubidium-strontium method

answers: NDQ_005712

answers: 12 <unk> 2 million years

answers: NDQ_005713

answers: rubidium-strontium method

answers: NDQ_005714

answers: The radiometric age

answers: NDQ_005715

answers: 12 <unk> 2 million years

answers: NDQ_005716

answers: The radiometric age

answers: NDQ_005717

answers: 13 <unk> 1 million years

answers: NDQ_005718

answers: High resolution

answers: NDQ_005719

answers: U/Pb methods on single zircon crystals.

answers: NDQ_005720

answers: U/Pb

text: The three known Deinocheirus specimens were recovered from the Nemegt Formation in the Gobi Desert of southern Mongolia. This geologic formation has never been dated radiometrically, but the fauna present in the fossil record indicate it was probably deposited during the early Maastrichtian stage, at the end of the Late Cretaceous about 70 million years ago. The rock facies of the Nemegt Formation suggest the presence of stream and river channels, mudflats, and shallow lakes. Such large river channels and soil deposits are evidence of a far more humid climate than those found in the older Barun Goyot and Djadochta formations. However, caliche deposits indicate at least periodic droughts occurred. Sediment was deposited in the channels and floodplains of large rivers.

text: The three known Deinocheirus specimens were recovered from the

text: Nemegt Formation

text: in the Gobi Desert of southern Mongolia. This

text: geologic formation

text: has never been

text: dated radiometrically

text: , but the

text: fauna

text: present in the fossil record indicate it was probably deposited during the early

text: Maastrichtian

text: stage, at the end of the

text: Late Cretaceous

text: about 70 million years ago. The rock

text: facies

text: of the Nemegt Formation suggest the presence of stream and river channels, mudflats, and shallow lakes. Such large river channels and soil deposits are evidence of a far more humid climate than those found in the older

text: Barun Goyot

text: and

text: Djadochta

text: formations. However,

text: caliche

text: deposits indicate at least periodic droughts occurred. Sediment was deposited in the channels and floodplains of large rivers.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: radiometric dating works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: has never been dated radiometrically

answers: NDQ_005718

answers: never been dated radiometrically

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: fauna present in the fossil record

answers: NDQ_005712

answers: Late Cretaceous about 70 million years ago.

answers: NDQ_005713

answers: 70 million years ago.

answers: NDQ_005714

answers: radiometrically,

answers: NDQ_005715

answers: 70 million years ago.

answers: NDQ_005716

answers: radiometrically,

answers: NDQ_005717

answers: This geologic formation has never been dated radiometrically,

answers: NDQ_005718

answers: This geologic formation has never been dated radiometrically,

answers: NDQ_005719

answers: radiometrically,

answers: NDQ_005720

answers: radiometrically,

text: 2009 - date     Corvette Marine (HK) Limited, built by Tung Hwa, Taiwan

text: 2009 - date     Corvette Marine (HK) Limited, built by Tung Hwa, Taiwan

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay is not present

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: 2009

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: Corvette Marine (HK) Limited

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Tung Hwa, Taiwan

answers: NDQ_005712

answers: 2009

answers: NDQ_005713

answers: Tung Hwa, Taiwan

answers: NDQ_005714

answers: Tung Hwa, Taiwan

answers: NDQ_005715

answers: Tung Hwa, Taiwan

answers: NDQ_005716

answers: 2009

answers: NDQ_005717

answers: Tung Hwa, Taiwan

answers: NDQ_005718

answers: 2009

answers: NDQ_005719

answers: Tung Hwa, Taiwan

answers: NDQ_005720

answers: Tung Hwa, Taiwan

text: While there are no major radiometric dates for the Hirnantian itself, there are two such dates which bracket the Hirnantian.  Both dates are from the Dob's Linn area in the United Kingdom.

text: While there are no major

text: radiometric

text: dates for the Hirnantian itself, there are two such dates which bracket the Hirnantian.  Both dates are from the

text: Dob's Linn

text: area in the United Kingdom.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Dob's Linn

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Dob's Linn

answers: NDQ_005718

answers: no major radiometric dates

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Dob's Linn area in the United Kingdom.

answers: NDQ_005712

answers: Dob's Linn area in the United Kingdom.

answers: NDQ_005713

answers: Dob's Linn area in the United Kingdom.

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: Dob's Linn area in the United Kingdom.

answers: NDQ_005716

answers: radiometric dates

answers: NDQ_005717

answers: Dob's Linn area in the United Kingdom.

answers: NDQ_005718

answers: no major radiometric dates for the Hirnantian itself,

answers: NDQ_005719

answers: radiometric dates

answers: NDQ_005720

answers: Dob's Linn area in the United Kingdom.

text: From 1996 to 2002, the award was dated for the previous year; since 2003, it has been dated for the same year. There is thus no award dated 2002.

text: From 1996 to 2002, the award was dated for the previous year; since 2003, it has been dated for the same year. There is thus no award dated 2002.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: isotope

answers: NDQ_005718

answers: not enough information

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 2003, it has been dated for the same year.

answers: NDQ_005712

answers: 1996

answers: NDQ_005713

answers: 2003,

answers: NDQ_005714

answers: From 1996 to 2002, the award was dated for the previous year;

answers: NDQ_005715

answers: From 1996 to 2002,

answers: NDQ_005716

answers: dated for the previous year;

answers: NDQ_005717

answers: no award dated 2002.

answers: NDQ_005718

answers: the same year.

answers: NDQ_005719

answers: From 1996 to 2002,

answers: NDQ_005720

answers: From 1996 to 2002,

text: Radiocarbon dates place the period of most intensive settlement firmly into the early Mesolithic. Using the calpal software, the Radiocarbon dates can be calibrated and expressed in calendar years, a convention followed here. Based on these results, the earliest living sites (Wp8 and Wp9) date to the late pre-boreal approximately 11,000 years ago. Wp19 is the youngest of the sites and dates to about 8,500 years ago. This is followed by a long settlement hiatus that lasted until during the Neolithic (Einzelgrabkultur).

text: Radiocarbon dates

text: place the period of most intensive settlement firmly into the early Mesolithic. Using the calpal software, the Radiocarbon dates can be

text: calibrated

text: and expressed in calendar years, a convention followed here. Based on these results, the earliest living sites (Wp8 and Wp9) date to the late pre-boreal approximately 11,000 years ago. Wp19 is the youngest of the sites and dates to about 8,500 years ago. This is followed by a long settlement hiatus that lasted until during the Neolithic (Einzelgrabkultur).

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: early Mesolithic

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: calpal software

answers: NDQ_005717

answers: Radiocarbon dates place the period of most intensive settlement firmly into the early Mesolithic

answers: NDQ_005718

answers: Radiocarbon dates place the period of most intensive settlement firmly into the early Mesolithic

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: early Mesolithic.

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: the Radiocarbon dates can be calibrated and expressed in calendar years,

answers: NDQ_005715

answers: 11,000 years ago. Wp19

answers: NDQ_005716

answers: Radiocarbon

answers: NDQ_005717

answers: 11,000 years ago.

answers: NDQ_005718

answers: calendar years,

answers: NDQ_005719

answers: 8,500 years ago.

answers: NDQ_005720

answers: Radiocarbon dates

text: In this episode, The Roadies reach Las Vegas where the Roadies had to pick a fellow Roadie for a romantic date of sorts. After the date, the boys get waxed as a part of a task. The boys also had to perform a Money Task where they were required to wear flamboyant outfits and perform on the streets of Vegas. Diyali and Taranjeet get into an epic fight which almost leads to Taranjeet quitting the show.

text: In this episode, The Roadies reach Las Vegas where the Roadies had to pick a fellow Roadie for a romantic date of sorts. After the date, the boys get waxed as a part of a task. The boys also had to perform a Money Task where they were required to wear flamboyant outfits and perform on the streets of Vegas. Diyali and Taranjeet get into an epic fight which almost leads to Taranjeet quitting the show.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12 with a half-life of 5,730 years

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: argon is a noble gas

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Diyali and Taranjeet get into an epic fight

answers: NDQ_005712

answers: Las Vegas

answers: NDQ_005713

answers: Diyali and Taranjeet get into an epic fight

answers: NDQ_005714

answers: romantic date

answers: NDQ_005715

answers: Diyali and Taranjeet get into an epic fight

answers: NDQ_005716

answers: romantic date

answers: NDQ_005717

answers: Diyali

answers: NDQ_005718

answers: Las Vegas

answers: NDQ_005719

answers: Diyali

answers: NDQ_005720

answers: Diyali and Taranjeet get into an epic fight

text: The circular topographic feature that marks the site was originally thought to be volcanic, with an impact origin first proposed in 1971 after the discovery of evidence diagnostic of impact including shatter cones and shocked quartz. The circular topographic feature is about  in diameter and lies within Mesoproterozoic sedimentary rocks of the McArthur Basin. However, this is only a relic of the original crater after considerable erosion. Estimates of the original rim diameter vary between different researchers in the range ; the Earth Impact Database prefers a diameter of . The age of the impact event has been determined at 646 ± 42 Ma (Neoproterozoic) based on radiometric dating of impact melt rocks.

text: The circular topographic feature that marks the site was originally thought to be volcanic, with an impact origin first proposed in 1971 after the discovery of evidence diagnostic of impact including

text: shatter cone

text: s and

text: shocked quartz

text: . The circular topographic feature is about  in diameter and lies within

text: Mesoproterozoic

text: sedimentary rock

text: s of the

text: McArthur Basin

text: . However, this is only a relic of the original crater after considerable erosion. Estimates of the original rim diameter vary between different researchers in the range ; the Earth Impact Database prefers a diameter of . The age of the impact event has been determined at 646 ± 42

text: Ma

text: Neoproterozoic

text: ) based on

text: radiometric dating

text: of impact melt rocks.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: impact melt rocks

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: How long does the half-life of carbon-14 decay?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: estimates of the original rim diameter vary between different researchers

answers: NDQ_005719

answers: What is the age of the impact event?

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: impact melt rocks.

answers: NDQ_005712

answers: impact melt rocks.

answers: NDQ_005713

answers: impact melt rocks.

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: 646 <unk> 42 Ma

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating of impact melt rocks.

answers: NDQ_005718

answers: Estimates of the original rim diameter vary between different researchers

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: The origins of the Jeulmun are not well known, but raised-clay pattern Yunggimun pottery (Hangul: 융기문토기; Hanja: 隆起文土器) appear at southern sites such as Gosan-ni in Jeju-do Island and Ubong-ni on the seacoast in Ulsan. Some archaeologists describe this range of time as the "Incipient Jeulmun period" and suggest that the Gosan-ni pottery dates to 10,000 BP. Samples of the pottery were radiocarbon dated, and although one result is consistent with the argument that pottery emerged at very early date (i.e. 10,180±65 BP [AA-38105]), other dates are somewhat later. If the earlier dating holds true, Yunggimun pottery from Gosan-ni would be, along with central and southern China, the Japanese Archipelago, and the Russian Far East, among a group of the oldest known pottery in world prehistory. Kuzmin suggests that more absolute dating is needed to gain a better perspective on this notion.

text: The origins of the Jeulmun are not well known, but raised-clay pattern

text: Yunggimun

text: pottery (

text: Hangul

text: : 융기문토기;

text: Hanja

text: : 隆起文土器) appear at southern sites such as Gosan-ni in

text: Jeju-do

text: Island and Ubong-ni on the seacoast in

text: Ulsan

text: . Some archaeologists describe this range of time as the "Incipient Jeulmun period" and suggest that the Gosan-ni pottery dates to 10,000 BP. Samples of the pottery were radiocarbon dated, and although one result is consistent with the argument that pottery emerged at very early date (i.e. 10,180±65 BP [AA-38105]), other dates are somewhat later. If the earlier dating holds true, Yunggimun pottery from Gosan-ni would be, along with central and southern China, the

text: Japanese Archipelago

text: , and the

text: Russian Far East

text: , among a group of the oldest known

text: pottery

text: in world

text: prehistory

text: . Kuzmin suggests that more

text: absolute dating

text: is needed to gain a better perspective on this notion.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 10180 65 BP

answers: NDQ_005718

answers: other dates are somewhat later

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dated,

answers: NDQ_005717

answers: 10,180<unk>65 BP

answers: NDQ_005718

answers: other dates are somewhat later.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dated,

text: One problem with argon-argon dating has been a slight discrepancy with other methods of dating. Recent work by Kuiper (see also Kerr) reports that a correction of 0.65% is needed. Thus the Cretaceous–Paleogene extinction (when the dinosaurs died out) - previously dated at 65.0 or 65.5 million years ago - is more accurately dated to 66.0 Ma.  Similarly, the Permian-Triassic extinction is now dated at 252.5 Ma, which is effectively coincident with the age determined by other means for Siberian Traps basalt flows.

text: One problem with argon-argon dating has been a slight discrepancy with other methods of dating. Recent work by Kuiper (see also Kerr) reports that a correction of 0.65% is needed. Thus the

text: Cretaceous–Paleogene extinction

text: (when the dinosaurs died out) - previously dated at 65.0 or 65.5 million years ago - is more accurately dated to 66.0 Ma.  Similarly, the

text: Permian-Triassic extinction

text: is now dated at 252.5 Ma, which is effectively coincident with the age determined by other means for

text: Siberian Traps

text: basalt flows.

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: argon-argon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: argon-argon

answers: NDQ_005715

answers: NDQ_005716

answers: argon-argon

answers: NDQ_005717

answers: a slight discrepancy

answers: NDQ_005718

answers: slight discrepancy

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: argon-argon

answers: NDQ_005712

answers: coincident with the age determined by other means

answers: NDQ_005713

answers: argon-argon

answers: NDQ_005714

answers: argon-argon

answers: NDQ_005715

answers: argon-argon

answers: NDQ_005716

answers: argon-argon

answers: NDQ_005717

answers: argon-argon

answers: NDQ_005718

answers: a slight discrepancy with other methods of dating.

answers: NDQ_005719

answers: argon-argon

answers: NDQ_005720

answers: argon-argon

text: However, the hypothesis has been generally dismissed. First, detailed dating of varved and other lake deposits in other maar lakes determined an age of at least 11,230 ± 40 radiocarbon years BP for the Laacher See eruption. This radiocarbon age would make the Laacher see eruption about 200 radiocarbon years older than the start of the Younger Dryas. More recently, the radiocarbon dating of trees killed by the Laacher See eruption and an examination of Swiss dendrochronology and volcanic sulphur in the Greenland ice cores concluded that the Laacher See eruption predated the onset of the Younger Dryas by some 203 calendar years on average. Second, Late-Glacial sediment cores from Switzerland demonstrate that a significant period of time separate the Laacher See eruption and the start of the Younger Dryas. Even if the Laacher See eruption was contemporaneous with the start of the Younger Dryas, it was not large enough to initiate a new stadial. The paleoclimatic proxies found in Greenland ice cores show only a short-term climatic deterioration.

text: However, the hypothesis has been generally dismissed. First, detailed dating of

text: varve

text: d and other lake deposits in other maar lakes determined an age of at least 11,230 ± 40 radiocarbon years BP for the Laacher See eruption. This radiocarbon age would make the Laacher see eruption about 200 radiocarbon years older than the start of the Younger Dryas. More recently, the radiocarbon dating of trees killed by the Laacher See eruption and an examination of Swiss dendrochronology and volcanic sulphur in the Greenland ice cores concluded that the Laacher See eruption predated the onset of the Younger Dryas by some 203 calendar years on average. Second, Late-Glacial sediment cores from Switzerland demonstrate that a significant period of time separate the Laacher See eruption and the start of the Younger Dryas. Even if the Laacher See eruption was contemporaneous with the start of the Younger Dryas, it was not large enough to initiate a new stadial. The paleoclimatic proxies found in Greenland ice cores show only a short-term climatic deterioration.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: it was not large enough to initiate a new stadial

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon years BP

answers: NDQ_005712

answers: 11,230 <unk> 40 radiocarbon years BP

answers: NDQ_005713

answers: 11,230 <unk> 40 radiocarbon years BP

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 200 radiocarbon years older than the start of the Younger Dryas.

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 11,230 <unk> 40 radiocarbon years BP

answers: NDQ_005718

answers: it was not large enough to initiate a new stadial.

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: 11,230 <unk> 40 radiocarbon years BP

text: Numerous television reality and game shows, past and current, address dating. For example, the dating game shows The Dating Game first aired in 1965, while more modern shows in that genre include The Manhattan Dating Project (US Movie about Dating in New York City), Blind Date, The 5th Wheel, and The Bachelor and its spinoff series, in which a high degree of support and aids are provided to individuals seeking dates. These are described more fully here and in the related article on "reality game shows" that often include or motivate romantic episodes between players.  Another category of dating-oriented reality TV shows involves matchmaking, such as Millionaire Matchmaker and Tough Love.

text: Numerous

text: television reality

text: and

text: game show

text: s, past and current, address dating. For example, the

text: dating game show

text: s

text: The Dating Game

text: first aired in 1965, while more modern shows in that genre include

text: The Manhattan Dating Project

text: (US Movie about Dating in New York City),

text: Blind Date

text: The 5th Wheel

text: , and

text: The Bachelor

text: and its spinoff series, in which a high degree of support and aids are provided to individuals seeking dates. These are described more fully

text: here

text: and in the related article on "

text: reality game show

text: s" that often include or motivate romantic episodes between players.  Another category of dating-oriented reality TV shows involves

text: matchmaking

text: , such as

text: Millionaire Matchmaker

text: and

text: Tough Love

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these age

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The Manhattan Dating Project

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: What is the difference between potassium-argon and uranium-lead dating

answers: NDQ_005720

answers: NDQ_005711

answers: "reality game shows"

answers: NDQ_005712

answers: 1965,

answers: NDQ_005713

answers: "reality game shows"

answers: NDQ_005714

answers: "reality game shows"

answers: NDQ_005715

answers: "reality game shows"

answers: NDQ_005716

answers: "reality game shows"

answers: NDQ_005717

answers: matchmaking,

answers: NDQ_005718

answers: a high degree of support and aids are provided to individuals seeking dates.

answers: NDQ_005719

answers: "reality game shows"

answers: NDQ_005720

answers: "reality game shows"

text: The Bleeding Horse is a historically significant pub in Upper Camden Street, Dublin, Ireland.It dates at least back to the 17th century, and was located on St. Kevin's Port (now Camden St.) at the junction of two important highways leading out of the city. On one side was Charlotte St., leading to Ranelagh and Donnybrook; on the other side was Old Camden St., which joined Richmond St. and led to Rathmines and Cullenswood. Both of these old streets disappeared during the renovations in the 1990s. The present building dates from 1871; the interior was renovated in 1992.

text: The Bleeding Horse is a historically significant

text: pub

text: in Upper Camden Street,

text: Dublin

text: Ireland

text: .It dates at least back to the 17th century, and was located on St. Kevin's Port (now Camden St.) at the junction of two important highways leading out of the city. On one side was Charlotte St., leading to

text: Ranelagh

text: and

text: Donnybrook

text: ; on the other side was Old Camden St., which joined Richmond St. and led to

text: Rathmines

text: and Cullenswood. Both of these old streets disappeared during the renovations in the 1990s. The present building dates from 1871; the interior was renovated in 1992.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: It dates at least back to the 17th century

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: 17th century,

answers: NDQ_005712

answers: 17th century,

answers: NDQ_005713

answers: 1871;

answers: NDQ_005714

answers: 17th century,

answers: NDQ_005715

answers: 1871;

answers: NDQ_005716

answers: 1871;

answers: NDQ_005717

answers: 17th century,

answers: NDQ_005718

answers: Both of these old streets disappeared during the renovations in the 1990s.

answers: NDQ_005719

answers: 1871;

answers: NDQ_005720

answers: 17th century,

text: The discovery of the radioactivity of uranium ushered in additional scientific and practical uses of the element. The long half-life of the isotope uranium-238 (4.51 years) makes it well-suited for use in estimating the age of the earliest igneous rocks and for other types of radiometric dating, including uranium-thorium dating, uranium-lead dating and uranium-uranium dating. Uranium metal is used for X-ray targets in the making of high-energy X-rays.

text: The discovery of the radioactivity of uranium ushered in additional scientific and practical uses of the element. The long

text: half-life

text: of the isotope uranium-238 (4.51 years) makes it well-suited for use in estimating the age of the earliest

text: igneous rock

text: s and for other types of

text: radiometric dating

text: , including

text: uranium-thorium dating

text: uranium-lead dating

text: and

text: uranium-uranium dating

text: . Uranium metal is used for

text: X-ray

text: targets in the making of high-energy X-rays.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium-238

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: uranium-238

answers: NDQ_005718

answers: half-life of the isotope uranium-238

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: The long half-life

answers: NDQ_005712

answers: earliest igneous rocks

answers: NDQ_005713

answers: uranium-238

answers: NDQ_005714

answers: The long half-life

answers: NDQ_005715

answers: uranium-238

answers: NDQ_005716

answers: radiometric dating,

answers: NDQ_005717

answers: uranium-thorium dating,

answers: NDQ_005718

answers: The long half-life

answers: NDQ_005719

answers: uranium-thorium

answers: NDQ_005720

answers: uranium-238

text: This involves electron capture or positron decay of potassium-40 to argon-40. Potassium-40 has a half-life of 1.3 billion years, and so this method is applicable to the oldest rocks. Radioactive potassium-40 is common in micas, feldspars, and hornblendes, though the closure temperature is fairly low in these materials, about 350 °C (mica) to 500 °C (hornblende).

text: This involves

text: electron capture

text: or

text: positron

text: decay of potassium-40 to argon-40. Potassium-40 has a half-life of 1.3 billion years, and so this method is applicable to the oldest rocks. Radioactive potassium-40 is common in

text: mica

text: s,

text: feldspar

text: s, and

text: hornblende

text: s, though the closure temperature is fairly low in these materials, about 350 °C (mica) to 500 °C (hornblende).

answers: NDQ_005711

answers: positron decay

answers: NDQ_005712

answers: Potassium-40 has a half-life

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-40 has a half-life of 1.3 billion years

answers: NDQ_005715

answers: NDQ_005716

answers: positron decay

answers: NDQ_005717

answers: electron capture or positron decay

answers: NDQ_005718

answers: closure temperature is fairly low in these materials

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: electron capture or positron decay of potassium-40 to argon-40.

answers: NDQ_005712

answers: Potassium-40 has a half-life of 1.3 billion years,

answers: NDQ_005713

answers: electron capture or positron decay of potassium-40 to argon-40.

answers: NDQ_005714

answers: Potassium-40 has a half-life of 1.3 billion years,

answers: NDQ_005715

answers: 1.3 billion years,

answers: NDQ_005716

answers: electron capture or positron decay of potassium-40 to argon-40.

answers: NDQ_005717

answers: electron capture or positron decay of potassium-40 to argon-40.

answers: NDQ_005718

answers: closure temperature is fairly low in these materials,

answers: NDQ_005719

answers: potassium-40 to argon-40.

answers: NDQ_005720

answers: potassium-40 to argon-40.

text: Many contemporary uses of uranium exploit its unique nuclear properties. Uranium-235 has the distinction of being the only naturally occurring fissile isotope. Uranium-238 is fissionable by fast neutrons, and is fertile, meaning it can be transmuted to fissile plutonium-239 in a nuclear reactor. Another fissile isotope, uranium-233, can be produced from natural thorium and is also important in nuclear technology. Uranium-238 has a small probability for spontaneous fission or even induced fission with fast neutrons; uranium-235 and to a lesser degree uranium-233 have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained nuclear chain reaction. This generates the heat in nuclear power reactors, and produces the fissile material for nuclear weapons. Depleted uranium (U) is used in kinetic energy penetrators and armor plating. Uranium is used as a colorant in uranium glass, producing lemon yellow to green colors. Uranium glass fluoresces green in ultraviolet light. It was also used for tinting and shading in early photography.

text: Many contemporary uses of uranium exploit its unique

text: nuclear

text: properties. Uranium-235 has the distinction of being the only naturally occurring

text: fissile

text: isotope

text: . Uranium-238 is fissionable by fast neutrons, and is

text: fertile

text: , meaning it can be

text: transmuted

text: to fissile

text: in a

text: nuclear reactor

text: . Another fissile isotope,

text: , can be produced from natural

text: thorium

text: and is also important in nuclear technology. Uranium-238 has a small probability for

text: spontaneous fission

text: or even induced fission with fast neutrons; uranium-235 and to a lesser degree uranium-233 have a much higher fission cross-section for slow neutrons. In sufficient concentration, these isotopes maintain a sustained

text: nuclear chain reaction

text: . This generates the heat in nuclear power reactors, and produces the fissile material for

text: nuclear weapon

text: s.

text: Depleted uranium

text: (U) is used in

text: kinetic energy penetrator

text: s and

text: armor plating

text: . Uranium is used as a colorant in

text: uranium glass

text: , producing lemon yellow to green colors. Uranium glass fluoresces green in ultraviolet light. It was also used for tinting and shading in early

text: photography

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium glass fluoresces green in ultraviolet light

answers: NDQ_005713

answers: How is radiometric dating used?

answers: NDQ_005714

answers: uranium-238 is fissionable by fast neutrons

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: plutonium-239

answers: NDQ_005717

answers: Uranium-235 has the distinction of being the only naturally occurring fissile isotope

answers: NDQ_005718

answers: Uranium-238 has a small probability for spontaneous fission

answers: NDQ_005719

answers: What is used as a colorant in uranium glass?

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: nuclear properties.

answers: NDQ_005712

answers: Uranium-235

answers: NDQ_005713

answers: uranium glass,

answers: NDQ_005714

answers: uranium exploit its unique nuclear properties.

answers: NDQ_005715

answers: uranium glass, producing lemon yellow to green colors.

answers: NDQ_005716

answers: Uranium-235

answers: NDQ_005717

answers: Uranium glass fluoresces green in ultraviolet light.

answers: NDQ_005718

answers: fission cross-section for slow neutrons.

answers: NDQ_005719

answers: uranium glass,

answers: NDQ_005720

answers: Uranium-235

text: K–Ar dates on the lava are about 70 ka, but are considered unreliable because of excess argon and the un-weathered young appearance of the cone.

text: K–Ar dates

text: on the lava are about 70

text: ka

text: , but are considered unreliable because of excess

text: argon

text: and the un-weathered young appearance of the cone.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: K–Ar

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 70 ka

answers: NDQ_005718

answers: unreliable

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: K–Ar

answers: NDQ_005712

answers: un-weathered young appearance of the cone.

answers: NDQ_005713

answers: unreliable

answers: NDQ_005714

answers: unreliable

answers: NDQ_005715

answers: K–Ar dates on the lava are about 70 ka,

answers: NDQ_005716

answers: K–Ar

answers: NDQ_005717

answers: 70 ka,

answers: NDQ_005718

answers: un-weathered young appearance of the cone.

answers: NDQ_005719

answers: unreliable

answers: NDQ_005720

answers: K–Ar dates on the lava are about 70 ka,

text: Archaeologists, anthropologists and other researchers have been studying rock art to gain information about African cultures from the past. Studying the disappearing evidence from the past is difficult. Many photographs are taken of the art so they can be studied further. At the sites, research techniques such as dating the art are made possible through radiometric dating of organic material, as well as carbon dating. Surrounding organic artifacts are used for dating, or residue that is on the rock art itself.

text: Archaeologist

text: s,

text: anthropologist

text: s and other researchers have been studying rock art to gain information about

text: African cultures

text: from the past. Studying the disappearing evidence from the past is difficult. Many photographs are taken of the art so they can be studied further. At the sites, research techniques such as dating the art are made possible through

text: radiometric dating

text: of

text: organic material

text: , as well as

text: carbon dating

text: . Surrounding organic

text: artifact

text: s are used for dating, or residue that is on the rock art itself.

answers: NDQ_005711

answers: carbon dating

answers: NDQ_005712

answers: organic material

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: radiometric dating of organic material

answers: NDQ_005715

answers: how long does carbon-14 decay to carbon-12?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: organic material

answers: NDQ_005718

answers: Studying the disappearing evidence from the past

answers: NDQ_005719

answers: None of the above choices.

answers: NDQ_005720

answers: NDQ_005711

answers: organic material,

answers: NDQ_005712

answers: organic material,

answers: NDQ_005713

answers: radiometric dating of organic material, as well as carbon dating.

answers: NDQ_005714

answers: Surrounding organic artifacts

answers: NDQ_005715

answers: carbon dating.

answers: NDQ_005716

answers: carbon dating.

answers: NDQ_005717

answers: radiometric dating of organic material,

answers: NDQ_005718

answers: Studying the disappearing evidence

answers: NDQ_005719

answers: carbon dating.

answers: NDQ_005720

answers: radiometric dating

text: One of the major drawbacks (and, conversely, the most important use) of utilizing Rb and Sr to derive a radiometric date is their relative mobility, especially in hydrothermal fluids. Rb and Sr are relatively mobile alkaline elements and as such are relatively easily moved around by the hot, often carbonated hydrothermal fluids present during metamorphism or magmatism.

text: One of the major drawbacks (and, conversely, the most important use) of utilizing Rb and Sr to derive a radiometric date is their relative mobility, especially in

text: hydrothermal

text: fluids. Rb and Sr are relatively mobile alkaline elements and as such are relatively easily moved around by the hot, often

text: carbonate

text: d hydrothermal fluids present during metamorphism or magmatism.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: hydrothermal fluids

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Rb and Sr are relatively mobile

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: are relatively mobile alkaline elements

answers: NDQ_005718

answers: relative mobility

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiometric date is their relative mobility, especially in hydrothermal fluids.

answers: NDQ_005712

answers: metamorphism or magmatism.

answers: NDQ_005713

answers: relative mobility, especially in hydrothermal fluids.

answers: NDQ_005714

answers: their relative mobility, especially in hydrothermal fluids.

answers: NDQ_005715

answers: relative mobility, especially in hydrothermal fluids.

answers: NDQ_005716

answers: radiometric date

answers: NDQ_005717

answers: their relative mobility, especially in hydrothermal fluids.

answers: NDQ_005718

answers: their relative mobility,

answers: NDQ_005719

answers: relative mobility, especially in hydrothermal fluids.

answers: NDQ_005720

answers: Rb and Sr to derive a radiometric date

text: The vast majority of known Tarbosaurus fossils were recovered from the Nemegt Formation in the Gobi Desert of southern Mongolia. This geologic formation has never been dated radiometrically, but the fauna present in the fossil record indicate it was probably deposited during the early Maastrichtian stage, at the end of the Late Cretaceous about 70 million years ago. The Subashi Formation, in which Shanshanosaurus remains were discovered, is also Maastrichtian in age.

text: The vast majority of known Tarbosaurus fossils were recovered from the

text: Nemegt Formation

text: in the

text: Gobi Desert

text: of southern Mongolia. This

text: geologic formation

text: has never been

text: dated radiometrically

text: , but the

text: fauna

text: present in the fossil record indicate it was probably deposited during the early

text: Maastrichtian

text: stage, at the end of the

text: Late Cretaceous

text: about 70 million years ago. The

text: Subashi Formation

text: , in which Shanshanosaurus remains were discovered, is also Maastrichtian in age.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: Maastrichtian

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometrically

answers: NDQ_005718

answers: never been dated radiometrically

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: fauna present in the fossil record

answers: NDQ_005712

answers: Maastrichtian

answers: NDQ_005713

answers: Maastrichtian

answers: NDQ_005714

answers: radiometrically,

answers: NDQ_005715

answers: Maastrichtian

answers: NDQ_005716

answers: radiometrically,

answers: NDQ_005717

answers: This geologic formation has never been dated radiometrically,

answers: NDQ_005718

answers: This geologic formation has never been dated radiometrically,

answers: NDQ_005719

answers: radiometrically,

answers: NDQ_005720

answers: radiometrically,

text: In 1978, the radiocarbon laboratory operated by the Department of Geology at the University of Miami dated samples from a core collected by E. A. Shinn in 1977 from the Bimini Road. In 1979, Calvert and others reported dates of 2780±70  yr BP (UM-1359), 3500±80  yr BP (UM-1360), and 3350±90  yr BP (UM-1361) from whole-rock samples; a date of 3510±70  yr BP (UM-1362), from shells extracted from the beachrock core; and dates of 2770±80  yr BP (UM-1364) and 2840±70  yr BP (UM-1365) from carbonate cementing the beachrock core. These dates are temporally consistent in that the shells composing the beachrock core from the Bimini Road dated older than the cement holding them together as beachrock. These dates can be interpreted as indicating that the shells composing the Bimini Road are, uncorrected for temporal and environmental variations in radiocarbon, about 3,500 years old. Because of time-averaging and other taphonomic factors, a random collection of shells likely would yield a radiocarbon date that is a few hundred years earlier than when the final accumulation of shells, which were cemented to form beachrock, actually occurred. The radiocarbon dates from the cement demonstrate that the beachrock composing the Bimini Road formed about 2,800 radiocarbon years ago by the cementation of pre-existing sediments that accumulated about 1,300 years earlier. Compared to the dates from the shells and the cement, it appears that the whole-rock dates reflect samples containing varying proportions of shell and cement without any significant contamination by younger radiocarbon. Both these dates and interpretation are consistent with the detailed research by Davaud and Strasser that concluded that the layer of beachrock composing the Bimini Road formed beneath the surface of North Bimini Island and was only exposed by coastal erosion about 1,900 to 2,000 years ago.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: time-averaging and other taphonomic factors

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: carbonate cementing the beachrock core

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: carbonate cementing

answers: NDQ_005717

answers: Calvert and others reported dates of 2780 70 yr BP

answers: NDQ_005718

answers: time-averaging and other taphonomic factors

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: NDQ_005711

answers: time-averaging and other taphonomic factors,

answers: NDQ_005712

answers: time-averaging and other taphonomic factors,

answers: NDQ_005713

answers: 2,800 radiocarbon years

answers: NDQ_005714

answers: temporally consistent

answers: NDQ_005715

answers: cement holding them together as beachrock.

answers: NDQ_005716

answers: radiocarbon,

answers: NDQ_005717

answers: dated older than the cement holding them together as beachrock.

answers: NDQ_005718

answers: time-averaging

answers: NDQ_005719

answers: radiocarbon,

answers: NDQ_005720

answers: shells, which were cemented to form beachrock,

text: Allorapisma chuorum is known only from two fossils, the part side of the holotype left fore-wing, specimen number SR 08-14-01, and the part side of a paratype right fore-wing, specimen number SRUI 08-04-01. Both the fossil are currently housed in the collections of the Stonerose Interpretive Center Republic, Washington, US.  The specimens are preserved as compression fossils in silty yellow to grayish shale, which were recovered from outcrops of the Tom Thumb Tuff member of the Klondike Mountain Formation.  The formation is approximately Early Eocene, Ypresian in age, being radiometrically dated as .

text: Allorapisma chuorum is known only from two fossils, the

text: part side

text: of the

text: holotype

text: left fore-wing, specimen number SR 08-14-01, and the part side of a

text: paratype

text: right fore-wing, specimen number SRUI 08-04-01. Both the fossil are currently housed in the collections of the

text: Stonerose Interpretive Center

text: Republic, Washington

text: , US.  The specimens are preserved as

text: compression fossil

text: s in silty yellow to grayish

text: shale

text: , which were recovered from outcrops of the Tom Thumb Tuff member of the

text: Klondike Mountain Formation

text: .  The formation is approximately

text: Early Eocene

text: Ypresian

text: in age, being radiometrically dated as .

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Early Eocene

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometrically

answers: NDQ_005718

answers: Ypresian in age

answers: NDQ_005719

answers: radiometrically

answers: NDQ_005720

answers: NDQ_005711

answers: Early Eocene, Ypresian

answers: NDQ_005712

answers: Early Eocene, Ypresian

answers: NDQ_005713

answers: Early Eocene, Ypresian

answers: NDQ_005714

answers: radiometrically dated

answers: NDQ_005715

answers: Klondike Mountain Formation.

answers: NDQ_005716

answers: radiometrically dated

answers: NDQ_005717

answers: radiometrically dated as.

answers: NDQ_005718

answers: Ypresian in age,

answers: NDQ_005719

answers: radiometrically dated

answers: NDQ_005720

answers: Ypresian

text: The largest application for elemental fluorine is the preparation of uranium hexafluoride, which is used in the production of nuclear fuels. To obtain the compound, uranium dioxide is first treated with hydrofluoric acid, to produce uranium tetrafluoride. This compound is then further fluorinated by direct exposure to fluorine gas to make the hexafluoride. Fluorine's monoisotopic natural occurrence makes it useful in uranium enrichment, because uranium hexafluoride molecules will differ in mass only because of mass differences between uranium-235 and uranium-238. These mass differences are used to separate uranium-235 and uranium-238 via diffusion and centrifugation. Up to 7,000 metric tons per year of fluorine gas are used for this application.  As of 2013, 686,500 metric tons of  UF6, containing about 470,000 metric tons of depleted uranium (the remainder being fluorine), were stored at the Paducah Gaseous Diffusion Plant, the USEC's Piketon site, Ohio and the East Tennessee Technology Park (formerly known as the K-25 Site).

text: The largest application for elemental fluorine is the preparation of

text: uranium hexafluoride

text: , which is used in the production of

text: nuclear fuel

text: s. To obtain the compound,

text: uranium dioxide

text: is first treated with hydrofluoric acid, to produce

text: uranium tetrafluoride

text: . This compound is then further fluorinated by direct exposure to fluorine gas to make the hexafluoride. Fluorine's monoisotopic natural occurrence makes it useful in

text: uranium enrichment

text: , because uranium hexafluoride molecules will differ in mass only because of mass differences between uranium-235 and uranium-238. These mass differences are used to separate uranium-235 and uranium-238 via diffusion and centrifugation. Up to 7,000 metric tons per year of fluorine gas are used for this application.  As of 2013, 686,500 metric tons of  UF6, containing about 470,000 metric tons of

text: depleted uranium

text: (the remainder being fluorine), were stored at the

text: Paducah Gaseous Diffusion Plant

text: , the

text: USEC's Piketon site, Ohio

text: and the

text: East Tennessee Technology Park

text: (formerly known as the K-25 Site).

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium-235 and uranium-238

answers: NDQ_005713

answers: NDQ_005714

answers: uranium 235 and uranium-238

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: uranium-235 and uranium-238

answers: NDQ_005717

answers: mass differences between uranium-235 and uranium-238

answers: NDQ_005718

answers: depleted uranium

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: monoisotopic natural occurrence

answers: NDQ_005712

answers: uranium-235 and uranium-238.

answers: NDQ_005713

answers: uranium hexafluoride,

answers: NDQ_005714

answers: Fluorine's monoisotopic natural occurrence

answers: NDQ_005715

answers: 686,500 metric tons of UF6,

answers: NDQ_005716

answers: uranium hexafluoride molecules will differ in mass

answers: NDQ_005717

answers: fluorine

answers: NDQ_005718

answers: mass differences

answers: NDQ_005719

answers: fluorine

answers: NDQ_005720

answers: uranium hexafluoride,

text: Other radiometric dating techniques are available for earlier periods.  One of the most widely used is potassium-argon dating (K-Ar dating).  Potassium-40 is a radioactive isotope of potassium that decays into argon-40.  The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, allowing much older samples to be dated. Potassium is common in rocks and minerals, allowing many samples of geochronological or archeological interest to be dated.

text: Other radiometric dating techniques are available for earlier periods.  One of the most widely used is

text: potassium-argon dating

text: (K-Ar dating).

text: is a radioactive isotope of potassium that decays into argon-40.  The half-life of potassium-40 is 1.3 billion years, far longer than that of carbon-14, allowing much older samples to be dated. Potassium is common in rocks and minerals, allowing many samples of

text: geochronological

text: or

text: archeological

text: interest to be dated.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium is common in rocks and minerals

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: half-life of potassium-40 is 1.3 billion years

answers: NDQ_005715

answers: half-life of potassium-40

answers: NDQ_005716

answers: half-life

answers: NDQ_005717

answers: K-Ar dating

answers: NDQ_005718

answers: carbon-14

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: potassium-argon dating

answers: NDQ_005712

answers: earlier periods.

answers: NDQ_005713

answers: potassium-argon dating (K-Ar dating).

answers: NDQ_005714

answers: The half-life

answers: NDQ_005715

answers: 1.3 billion years, far longer than that of carbon-14,

answers: NDQ_005716

answers: carbon-14,

answers: NDQ_005717

answers: The half-life of potassium-40 is 1.3 billion years,

answers: NDQ_005718

answers: carbon-14,

answers: NDQ_005719

answers: carbon-14,

answers: NDQ_005720

answers: potassium-argon dating

text: Zigrasimecia tonsora is only known from a single specimen, the holotype, specimen number JZC Bu-159. At the time of description, the specimen was residing in the private collection of James Zigras and only available for study through the American Museum of Natural History.  The solitary adult fossil is composed of a mostly-complete dealate adult female which has been preserved as an inclusion in transparent chunks of deep yellow and relatively clear Burmese amber. The amber specimen was recovered from deposits in Kachin State,  west of Myitkyina town in Myanmar. Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 99 million years old, close to the Aptian – Cenomanian boundary. The fossil was first studied by palaeoentomologists Phillip Barden and David Grimaldi, both of the AMNH. Barden and Grimaldi's 2013 type description of the new genus and species was published in the online journal Zootaxa. The genus name Zigrasimecia is a patronym which was coined as a combination of James Zigras' last name and -mecia which is a commonly used suffix in ant generic names. The specific epithet tonsora was derived from a combination of the Latin words tonsor meaning "barber" or "hairdresser" and oris meaning "mouth", in reference to the ants' mouthparts bearing combs and brushes. Zigrasimecia is one of seven ant species described from Burmese amber and one of the five Burmese amber species placed in Sphecomyrminae or incertae sedis. The other sphecomyrmin species are: Haidomyrmex cerberus, Haidomyrmex scimitarus, Haidomyrmex zigrasi, and Gerontoformica orientalis.

text: Zigrasimecia tonsora is only known from a single specimen, the

text: holotype

text: , specimen number JZC Bu-159. At the time of description, the specimen was residing in the private collection of James Zigras and only available for study through the

text: American Museum of Natural History

text: .  The solitary adult

text: fossil

text: is composed of a mostly-complete

text: dealate

text: adult female which has been preserved as an

text: inclusion

text: in transparent chunks of deep yellow and relatively clear

text: Burmese amber

text: . The

text: amber

text: specimen was recovered from deposits in

text: Kachin State

text: ,  west of

text: Myitkyina

text: town in

text: Myanmar

text: . Burmese amber has been

text: radiometrically dated

text: using

text: U

text: Pb

text: isotope

text: s, yielding an age of approximately 99 million years old, close to the

text: Aptian

text: Cenomanian

text: boundary. The fossil was first studied by palaeoentomologists Phillip Barden and

text: David Grimaldi

text: , both of the AMNH. Barden and Grimaldi's 2013

text: type description

text: of the new genus and species was published in the online journal

text: Zootaxa

text: . The genus name Zigrasimecia is a

text: patronym

text: which was coined as a combination of James Zigras' last name and -mecia which is a commonly used suffix in ant generic names. The

text: specific epithet

text: tonsora was derived from a combination of the

text: Latin

text: words tonsor meaning "barber" or "hairdresser" and oris meaning "mouth", in reference to the ants' mouthparts bearing combs and brushes. Zigrasimecia is one of seven ant species described from Burmese amber and one of the five Burmese amber species placed in Sphecomyrminae or

text: incertae sedis

text: . The other sphecomyrmin species are:

text: Haidomyrmex cerberus

text: Haidomyrmex scimitarus

text: Haidomyrmex zigrasi

text: , and

text: Gerontoformica orientalis

answers: NDQ_005711

answers: using U-Pb isotopes

answers: NDQ_005712

answers: U-Pb isotopes

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: U-Pb isotopes

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: yielding an age of approximately 99 million years old

answers: NDQ_005718

answers: close to the Aptian – Cenomanian boundary

answers: NDQ_005719

answers: What is the age of the specimen?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: U-Pb isotopes,

answers: NDQ_005712

answers: U-Pb isotopes,

answers: NDQ_005713

answers: U-Pb isotopes,

answers: NDQ_005714

answers: U-Pb isotopes,

answers: NDQ_005715

answers: Zigrasimecia

answers: NDQ_005716

answers: radiometrically dated using U-Pb isotopes,

answers: NDQ_005717

answers: U-Pb isotopes,

answers: NDQ_005718

answers: close to the Aptian – Cenomanian boundary.

answers: NDQ_005719

answers: U-Pb isotopes,

answers: NDQ_005720

answers: Zigrasimecia

text: Radiometric dates usually have high error margins - but in some cases precise ages are available.

text: Radiometric dates usually have high error margins - but in some cases precise ages are available.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: precision is available

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: high error margins

answers: NDQ_005718

answers: error margins

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Radiometric dates usually have high error margins

answers: NDQ_005712

answers: precise ages are available.

answers: NDQ_005713

answers: Radiometric dates usually have high error margins

answers: NDQ_005714

answers: Radiometric dates usually have high error margins

answers: NDQ_005715

answers: Radiometric dates usually have high error margins

answers: NDQ_005716

answers: Radiometric dates

answers: NDQ_005717

answers: precise ages are available.

answers: NDQ_005718

answers: high error margins

answers: NDQ_005719

answers: Radiometric dates usually have high error margins

answers: NDQ_005720

answers: Radiometric dates usually have high error margins

text: Dendrochronology can also be used in concert with radiocarbon dating to allow for more accurate date measurements using radiocarbon dating on archaeological sites. It is known that the concentration of carbon-14 in the atmosphere is not constant. By performing radiocarbon dating on timber samples in a known chronology, radiocarbon dates can be plotted against real time generating a calibration curve that can be used for future radiocarbon samples.

text: Dendrochronology can also be used in concert with

text: radiocarbon dating

text: to allow for more accurate date measurements using radiocarbon dating on archaeological sites. It is known that the concentration of carbon-14 in the atmosphere is not constant. By performing radiocarbon dating on timber samples in a known chronology, radiocarbon dates can be plotted against real time generating a calibration curve that can be used for future radiocarbon samples.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: carbon-14

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: it is not constant

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: the concentration of carbon-14 in the atmosphere is not constant

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: the concentration of carbon-14 in the atmosphere is not constant.

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: the concentration of carbon-14 in the atmosphere is not constant.

answers: NDQ_005715

answers: carbon-14 in the atmosphere is not constant.

answers: NDQ_005716

answers: date measurements

answers: NDQ_005717

answers: the concentration of carbon-14 in the atmosphere is not constant.

answers: NDQ_005718

answers: the concentration of carbon-14 in the atmosphere is not constant.

answers: NDQ_005719

answers: Dendrochronology

answers: NDQ_005720

answers: radiocarbon dating

text: Ages of the igneous rocks are important for understanding the evolution of the Colorado Plateau. Ages of these rocks were reported to be about 45 to 50 million years in older geologic literature. However, it has been established that these intrusions formed in the period from about 23 to 31 million years ago, using uranium-lead dating of zircon and argon-argon dating of hornblende; fission track dating also has yielded consistent results (the older, erroneous ages were by potassium-argon dating). The intrusions are hosted by Permian to Cretaceous sedimentary rocks. The geology of these mountains is similar to the geology of the La Sal Range and of the Abajo Mountains, both also on the Colorado Plateau in southeastern Utah: locations are shown on a satellite image presented with information about the La Sal Range.

text: Ages of the igneous rocks are important for understanding the evolution of the

text: Colorado Plateau

text: . Ages of these rocks were reported to be about 45 to 50 million years in older geologic literature. However, it has been established that these intrusions formed in the period from about 23 to 31 million years ago, using

text: uranium-lead dating

text: of

text: zircon

text: and

text: argon-argon dating

text: of

text: hornblende

text: fission track dating

text: also has yielded consistent results (the older, erroneous ages were by

text: potassium-argon dating

text: ). The intrusions are hosted by

text: Permian

text: to

text: Cretaceous

text: sedimentary rocks. The geology of these mountains is similar to the geology of the

text: La Sal Range

text: and of the

text: Abajo Mountains

text: , both also on the Colorado Plateau in southeastern Utah: locations are shown on a satellite image presented with information about the La Sal Range.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: uranium-lead

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: argon-argon dating

answers: NDQ_005717

answers: older, erroneous ages

answers: NDQ_005718

answers: fission track dating

answers: NDQ_005719

answers: yes

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead

answers: NDQ_005712

answers: 23 to 31 million years ago,

answers: NDQ_005713

answers: uranium-lead dating

answers: NDQ_005714

answers: uranium-lead dating

answers: NDQ_005715

answers: 45 to 50 million years in older geologic literature.

answers: NDQ_005716

answers: uranium-lead dating

answers: NDQ_005717

answers: (the older, erroneous ages

answers: NDQ_005718

answers: erroneous ages were by potassium-argon dating).

answers: NDQ_005719

answers: fission track dating

answers: NDQ_005720

answers: uranium-lead dating of zircon

text: Potassium-40 is especially important in potassium–argon (K–Ar) dating. Argon is a gas that does not ordinarily combine with other elements. So, when a mineral forms – whether from molten rock, or from substances dissolved in water – it will be initially argon-free, even if there is some argon in the liquid. However, if the mineral contains any potassium, then decay of the K isotope present will create fresh argon-40 that will remain locked up in the mineral. Since the rate at which this conversion occurs is known, it is possible to determine the elapsed time since the mineral formed by measuring the ratio of K and Ar atoms contained in it.

text: Potassium-40 is especially important in

text: potassium–argon (K–Ar) dating

text: . Argon is a gas that does not ordinarily combine with other elements. So, when a

text: mineral

text: forms – whether from molten

text: rock

text: , or from substances dissolved in water – it will be initially argon-free, even if there is some argon in the liquid. However, if the mineral contains any potassium, then decay of the K isotope present will create fresh argon-40 that will remain locked up in the mineral. Since the rate at which this conversion occurs is known, it is possible to determine the elapsed time since the mineral formed by measuring the ratio of K and Ar atoms contained in it.

answers: NDQ_005711

answers: decay

answers: NDQ_005712

answers: K–Ar

answers: NDQ_005713

answers: NDQ_005714

answers: argon isotope

answers: NDQ_005715

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: K–Ar

answers: NDQ_005718

answers: rate at which this conversion occurs is known

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: measuring the ratio of K and Ar atoms contained in it.

answers: NDQ_005712

answers: ratio of K and Ar atoms contained in it.

answers: NDQ_005713

answers: potassium–argon

answers: NDQ_005714

answers: Potassium-40 is especially important in potassium–argon

answers: NDQ_005715

answers: Potassium-40 is especially important in potassium–argon

answers: NDQ_005716

answers: K isotope present will create fresh argon-40

answers: NDQ_005717

answers: Potassium-40 is especially important

answers: NDQ_005718

answers: argon-40 that will remain locked up in the mineral.

answers: NDQ_005719

answers: potassium–argon

answers: NDQ_005720

answers: potassium–argon

text: Paleontology seeks to map out how living things have changed through time. A substantial hurdle to this aim is the difficulty of working out how old fossils are. Beds that preserve fossils typically lack the radioactive elements needed for radiometric dating. This technique is our only means of giving rocks greater than about 50 million years old an absolute age, and can be accurate to within 0.5% or better. Although radiometric dating requires very careful laboratory work, its basic principle is simple: the rates at which various radioactive elements decay are known, and so the ratio of the radioactive element to the element into which it decays shows how long ago the radioactive element was incorporated into the rock. Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are a few volcanic ash layers.

text: Paleontology seeks to map out how living things have changed through time. A substantial hurdle to this aim is the difficulty of working out how old fossils are. Beds that preserve fossils typically lack the radioactive elements needed for

text: radiometric dating

text: . This technique is our only means of giving rocks greater than about 50 million years old an absolute age, and can be accurate to within 0.5% or better. Although radiometric dating requires very careful laboratory work, its basic principle is simple: the rates at which various radioactive elements

text: decay

text: are known, and so the ratio of the radioactive element to the element into which it decays shows how long ago the radioactive element was incorporated into the rock. Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are a few volcanic ash layers.

answers: NDQ_005711

answers: rates at which various radioactive elements decay

answers: NDQ_005712

answers: rocks with a volcanic origin

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radioactive elements are common only in rocks with a volcanic origin

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radioactive elements decay

answers: NDQ_005717

answers: ratio of the radioactive element to the element into which it decays shows how long ago the radioactive element was incorporated into the rock

answers: NDQ_005718

answers: lack the radioactive elements needed for radiometric dating

answers: NDQ_005719

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: the ratio of the radioactive element to the element into which it decays

answers: NDQ_005712

answers: Radioactive elements are common only in rocks with a volcanic origin,

answers: NDQ_005713

answers: the ratio of the radioactive element to the element into which it decays

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: radiometric dating.

answers: NDQ_005716

answers: radioactive elements

answers: NDQ_005717

answers: the ratio of the radioactive element to the element into which it decays

answers: NDQ_005718

answers: difficulty of working out how old fossils are.

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: The glass is light to dark green, white or black.  The glass takes the form of twisted masses, fragments or chunks up to 10 cm.  Internally it has a flowing texture defined by lines of elliptical bubbles.There are two kinds of Darwin glass when composition is measured.  Type 1 is normally white or green whereas type 2 is normally black to dark green.  The dark glass contains less silica and more magnesium and iron than the light green glass.  The dark glass is also enriched in chromium, nickel and cobalt.  A possible explanation for the chemical differences is that, in addition to being mainly composed of melted local metamorphic rocks, the type 2 glass also contains a component of extraterrestrial material from the meteorite.Darwin glass has been dated at about 816,000 years old using argon dating methods.

text: The glass is light to dark green, white or black.  The glass takes the form of twisted masses, fragments or chunks up to 10 cm.  Internally it has a flowing texture defined by lines of elliptical bubbles.There are two kinds of Darwin glass when composition is measured.  Type 1 is normally white or green whereas type 2 is normally black to dark green.  The dark glass contains less

text: silica

text: and more

text: magnesium

text: and

text: iron

text: than the light green glass.  The dark glass is also enriched in

text: chromium

text: nickel

text: and

text: cobalt

text: .  A possible explanation for the chemical differences is that, in addition to being mainly composed of melted local

text: metamorphic rock

text: s, the type 2 glass also contains a component of extraterrestrial material from the meteorite.Darwin glass has been dated at about 816,000 years old using

text: argon dating

text: methods.

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: argon

answers: NDQ_005713

answers: unanswerable

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: argon dating methods

answers: NDQ_005718

answers: argon

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: argon

answers: NDQ_005713

answers: argon dating methods.

answers: NDQ_005714

answers: argon

answers: NDQ_005715

answers: 816,000 years old using argon

answers: NDQ_005716

answers: argon

answers: NDQ_005717

answers: argon dating methods.

answers: NDQ_005718

answers: argon

answers: NDQ_005719

answers: argon

answers: NDQ_005720

answers: argon dating methods.

text: Kostal Cone in the Wells Gray-Clearwater volcanic field of east-central British Columbia is a cinder cone responsible for basaltic lava flows comprising a lava bed, damming the southern end of McDougall Lake. There has been activity at this site as recently as 7,600 years ago at Dragon Cone, though more likely less than 1,000 years ago. Kostal Cone is too young for the potassium-argon dating technique (usable on specimens over 100,000 years old), and no charred organic material for radiocarbon dating has been found. However, the uneroded structure of the cone with the existence of trees on its flanks and summit have made it an area for dendrochronology studies, which reveals the growth of tree-ring patterns. Tree-ring dating has revealed an age of about 400 years for Kostal Cone, indicating it formed around 1500. This makes Kostal Cone the youngest volcano in the Wells Gray-Clearwater volcanic field and thus one of the youngest in Canada.

text: Kostal Cone

text: in the Wells Gray-Clearwater volcanic field of east-central British Columbia is a cinder cone responsible for basaltic lava flows comprising a lava bed, damming the southern end of

text: McDougall Lake

text: . There has been activity at this site as recently as 7,600 years ago at

text: Dragon Cone

text: , though more likely less than 1,000 years ago. Kostal Cone is too young for the

text: potassium-argon dating

text: technique (usable on specimens over 100,000 years old), and no charred organic material for

text: radiocarbon dating

text: has been found. However, the uneroded structure of the cone with the existence of trees on its flanks and summit have made it an area for

text: dendrochronology

text: studies, which reveals the growth of tree-ring patterns. Tree-ring dating has revealed an age of about 400 years for Kostal Cone, indicating it formed around 1500. This makes Kostal Cone the youngest volcano in the Wells Gray-Clearwater volcanic field and thus one of the youngest in Canada.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: charred organic material

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: no charred organic material has been found

answers: NDQ_005715

answers: How old is Kostal Cone?

answers: NDQ_005716

answers: charred organic material

answers: NDQ_005717

answers: Kostal Cone is too young

answers: NDQ_005718

answers: no charred organic material

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: over 100,000 years old),

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: charred organic material

answers: NDQ_005715

answers: 400 years for Kostal Cone, indicating it formed around 1500.

answers: NDQ_005716

answers: charred organic material

answers: NDQ_005717

answers: Kostal Cone is too young

answers: NDQ_005718

answers: no charred organic material

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: potassium-argon dating technique

text: Following the development of radiometric age dating in the early 20th century, measurements of lead in uranium-rich minerals showed that some were in excess of a billion years old.The oldest such minerals analyzed to date—small crystals of zircon from the Jack Hills of Western Australia—are at least 4.404 billion years old. Comparing the mass and luminosity of the Sun to those of other stars, it appears that the Solar System cannot be much older than those rocks. Calcium-aluminium-rich inclusions—the oldest known solid constituents within meteorites that are formed within the Solar System—are 4.567 billion years old, giving an age for the Solar System and an upper limit for the age of Earth.

text: Following the development of radiometric age dating in the early 20th century,

text: measurements of lead in uranium-rich minerals

text: showed that some were in excess of a billion years old.The oldest such minerals analyzed to date—small crystals of

text: zircon

text: from the

text: Jack Hills

text: of

text: Western Australia

text: —are at least 4.404 billion years old. Comparing the

text: mass

text: and

text: luminosity

text: of the

text: Sun

text: to those of other

text: star

text: s, it appears that the

text: Solar System

text: cannot be much older than those rocks.

text: Calcium-aluminium-rich inclusion

text: s—the oldest known solid constituents within meteorites that are formed within the Solar System—are 4.567 billion years old, giving an age for the Solar System and an upper limit for the age of

text: Earth

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: lead in uranium-rich minerals

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: measurement of lead in uranium-rich minerals

answers: NDQ_005718

answers: the Solar System cannot be much older than those rocks

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: yes

answers: NDQ_005711

answers: measurements of lead in uranium-rich minerals

answers: NDQ_005712

answers: in excess of a billion years old.The

answers: NDQ_005713

answers: 4.567 billion years old, giving an age for the Solar System

answers: NDQ_005714

answers: radiometric age dating

answers: NDQ_005715

answers: 4.567 billion years old, giving an age for the Solar System

answers: NDQ_005716

answers: radiometric age dating

answers: NDQ_005717

answers: 4.567 billion years old,

answers: NDQ_005718

answers: some were in excess of a billion years old.The

answers: NDQ_005719

answers: radiometric age dating

answers: NDQ_005720

answers: 4.404 billion years old.

text: Ages are given in "million year ago" (mya). They are obtained with different radiometric dating methods depending on the type of rock and its age. Ages that have a tilde (~) prefix are approximate ages for GSSPs that have not been defined or not been accurately dated.

text: Ages are given in "million year ago" (mya). They are obtained with different

text: radiometric dating

text: methods depending on the type of rock and its age. Ages that have a tilde (~) prefix are approximate ages for GSSPs that have not been defined or not been accurately dated.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: tilde

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: 5,730 years

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating methods

answers: NDQ_005718

answers: not been accurately dated

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: depending on the type of rock and its age.

answers: NDQ_005712

answers: type of rock and its age.

answers: NDQ_005713

answers: Ages are given in "million year ago" (mya).

answers: NDQ_005714

answers: radiometric dating methods depending on the type of rock and its age.

answers: NDQ_005715

answers: Ages are given in "million year ago"

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating methods depending on the type of rock and its age.

answers: NDQ_005718

answers: the type of rock and its age.

answers: NDQ_005719

answers: radiometric dating methods

answers: NDQ_005720

answers: radiometric dating methods

text: The doctrine was not initially welcome in medical malpractice cases. In Gray v. Wright, a seven-inch hemostat was left in Mrs. Gray during gall bladder surgery in June, 1947, and despite her chronic complaints about stomach pain over the years, the device was not found until an X-ray in March, 1953, when it was removed.  Her $12,000 award was reversed by the Supreme Court of West Virginia because she was outside the statutes of limitation when she filed and could not prove that the doctor concealed knowledge of his error. This "guilty knowledge" requirement disappeared over the years, and the "discovery rule" by which statutes of limitation run from the date of discovery of the wrongdoing rather than the date of the occurrence has become the rule in most states, allowing res ipsa loquitur to take its rightful place.

text: The doctrine was not initially welcome in medical malpractice cases. In Gray v. Wright, a seven-inch

text: hemostat

text: was left in Mrs. Gray during gall bladder surgery in June, 1947, and despite her chronic complaints about stomach pain over the years, the device was not found until an X-ray in March, 1953, when it was removed.  Her $12,000 award was reversed by the Supreme Court of West Virginia because she was outside the statutes of limitation when she filed and could not prove that the doctor concealed knowledge of his error. This "guilty knowledge" requirement disappeared over the years, and the "discovery rule" by which statutes of limitation run from the date of discovery of the wrongdoing rather than the date of the occurrence has become the rule in most states, allowing res ipsa loquitur to take its rightful place.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains and artifacts

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The doctrine was not initially welcome in medical malpractice cases.

answers: NDQ_005718

answers: statutes of limitation

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: X-ray

answers: NDQ_005712

answers: X-ray

answers: NDQ_005713

answers: The doctrine was not initially welcome in medical malpractice cases.

answers: NDQ_005714

answers: medical malpractice cases.

answers: NDQ_005715

answers: res ipsa loquitur

answers: NDQ_005716

answers: X-ray

answers: NDQ_005717

answers: res ipsa loquitur

answers: NDQ_005718

answers: statutes of limitation

answers: NDQ_005719

answers: X-ray

answers: NDQ_005720

answers: res ipsa loquitur

text: To be sure, the Pyu and their culture did not disappear just because 3000 of them were taken away. The size of the Pyu realm and its many walled cities throughout the land indicates a population many times over. Indeed, no firm indications at Sri Ksetra or at any other Pyu site exist to suggest a violent overthrow. It is more likely that these raids significantly weakened the Pyu states, enabling the Burmans to move into Pyu territories. At any rate, evidence shows that the actual pace of Burman migration into the Pyu realm was gradual. Radiocarbon dating shows that human activity existed until c. 870 at Halin, the subject of the 832 Nanzhao raid. The Burmese chronicles claim the Burmans founded the fortified city of Pagan (Bagan) in 849 but the oldest radiocarbon dated evidence at Pagan (old walls) points to 980 CE while the main walls point to circa 1020 CE, just 24 years earlier than the beginning of the reign of Anawrahta, the founder of Pagan Empire.

text: To be sure, the Pyu and their culture did not disappear just because 3000 of them were taken away. The size of the Pyu realm and its many walled cities throughout the land indicates a population many times over. Indeed, no firm indications at Sri Ksetra or at any other Pyu site exist to suggest a violent overthrow. It is more likely that these raids significantly weakened the Pyu states, enabling the Burmans to move into Pyu territories. At any rate, evidence shows that the actual pace of Burman migration into the Pyu realm was gradual. Radiocarbon dating shows that human activity existed until c. 870 at Halin, the subject of the 832 Nanzhao raid. The Burmese chronicles claim the Burmans founded the fortified city of

text: Pagan

text: (Bagan) in 849 but the oldest radiocarbon dated evidence at Pagan (old walls) points to 980 CE while the main walls point to circa 1020 CE, just 24 years earlier than the beginning of the reign of

text: Anawrahta

text: , the founder of Pagan Empire.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 832 Nanzhao raid

answers: NDQ_005718

answers: radiocarbon dating shows that human activity existed until c. 870 at Halin

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon dating shows that human activity existed until c. 870

answers: NDQ_005715

answers: Radiocarbon dating shows that human activity existed until c. 870

answers: NDQ_005716

answers: human activity existed until c. 870

answers: NDQ_005717

answers: human activity existed until c. 870 at Halin,

answers: NDQ_005718

answers: Radiocarbon

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: In December 2015 Professor François Déroche of the Collège de France confirmed the identification of the two Birmingham leaves with those of the Paris Qur'an BnF Arabe 328(c), as had been proposed by Dr Alba Fedeli.  Prof. Deroche, however, expressed reservations about the reliability of the radiocarbon dates proposed for the Birmingham leaves, noting instances elsewhere in which radiocarbon dating had proved inaccurate in testing Qur'ans with an explicit endowment date; and also that none of the counterpart Paris leaves had yet been carbon-dated. Dr Mustaf Shah, Senior Lecturer in Islamic Studies at the School of Oriental and African Studies, has suggested that the grammatical marks and verse separators in the Birmingham leaves are inconsistent with the proposed early radiocarbon dates. Jamal bin Huwareib, managing director of the Mohammed bin Rashid Al Maktoum Foundation, has proposed that, were the radiocarbon dates to be confirmed, the Birmingham/Paris Qur'an might be identified with the text known to have been assembled by the first Caliph Abu Bakr, between 632 CE and 634 CE.

text: In December 2015 Professor

text: François Déroche

text: of the

text: Collège de France

text: confirmed the identification of the two Birmingham leaves with those of the Paris Qur'an BnF Arabe 328(c), as had been proposed by Dr Alba Fedeli.  Prof. Deroche, however, expressed reservations about the reliability of the radiocarbon dates proposed for the Birmingham leaves, noting instances elsewhere in which radiocarbon dating had proved inaccurate in testing Qur'ans with an explicit endowment date; and also that none of the counterpart Paris leaves had yet been carbon-dated. Dr Mustaf Shah, Senior Lecturer in Islamic Studies at the

text: School of Oriental and African Studies

text: , has suggested that the grammatical marks and verse separators in the Birmingham leaves are inconsistent with the proposed early radiocarbon dates. Jamal bin Huwareib, managing director of the Mohammed bin Rashid Al Maktoum Foundation, has proposed that, were the radiocarbon dates to be confirmed, the Birmingham/Paris Qur'an might be identified with the text known to have been assembled by the first

text: Caliph

text: Abu Bakr

text: , between 632 CE and 634 CE.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating has proved inaccurate

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating had proved inaccurate

answers: NDQ_005718

answers: none of the counterpart Paris leaves had yet been carbon-dated

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: explicit endowment date;

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: inaccurate in testing Qur'ans with an explicit endowment date;

answers: NDQ_005715

answers: 632 CE and 634 CE.

answers: NDQ_005716

answers: endowment date;

answers: NDQ_005717

answers: inaccurate in testing Qur'ans with an explicit endowment date;

answers: NDQ_005718

answers: inaccurate in testing Qur'ans with an explicit endowment date;

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: The mineralisation is hosted by Palaeozoic meta-black shales and Meta-basalts. Uranium mineralisation occurs in irregular shaped bodies of highly variable size and uranium content (in average 70 tonnes of uranium per body). The uranium minerals (mainly pitchblende) occur as impregnations, thin veinlets or in breccia zones in these bodies. The deposit was formed by remobilsation of uranium already enriched in the black shales by synsedimentary processes. Remobilsation was caused by hydrothermal and supergene processes leading to the further enrichment of uranium. The background uranium content in the black shales is 40 to 60 ppm. Like the major vein-style uranium deposits in the western Erzgebirge mountains, the Ronneburg deposit is located on the Gera-Jachymov fault zone, which is called the Crimmitschau fault zone in this particular area.

text: The mineralisation is hosted by Palaeozoic meta-black shales and Meta-basalts. Uranium mineralisation occurs in irregular shaped bodies of highly variable size and uranium content (in average 70 tonnes of uranium per body). The uranium minerals (mainly pitchblende) occur as impregnations, thin veinlets or in breccia zones in these bodies. The deposit was formed by remobilsation of uranium already enriched in the black shales by synsedimentary processes. Remobilsation was caused by hydrothermal and supergene processes leading to the further enrichment of uranium. The background uranium content in the black shales is 40 to 60 ppm. Like the major vein-style uranium deposits in the western Erzgebirge mountains, the Ronneburg deposit is located on the Gera-Jachymov fault zone, which is called the Crimmitschau fault zone in this particular area.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Palaeozoic

answers: NDQ_005713

answers: How is radiometric dating used?

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: uranium minerals

answers: NDQ_005717

answers: Uranium mineralisation occurs in irregular shaped bodies

answers: NDQ_005718

answers: background uranium content

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Palaeozoic

answers: NDQ_005712

answers: Palaeozoic

answers: NDQ_005713

answers: Palaeozoic meta-black shales and Meta-basalts.

answers: NDQ_005714

answers: uranium already enriched in the black shales

answers: NDQ_005715

answers: Gera-Jachymov fault zone,

answers: NDQ_005716

answers: enrichment of uranium.

answers: NDQ_005717

answers: 40 to 60 ppm.

answers: NDQ_005718

answers: variable size and uranium content

answers: NDQ_005719

answers: Palaeozoic

answers: NDQ_005720

answers: Palaeozoic meta-black shales and Meta-basalts.

text: The dating method is usually performed on the mineral zircon. The mineral incorporates uranium and thorium atoms into its crystalline structure, but strongly rejects lead. Therefore, one can assume that the entire lead content of the zircon is radiogenic, i.e. it is produced solely by a process of radioactive decay after the formation of the mineral. Thus the current ratio of lead to uranium in the mineral can be used to determine its age.

text: The dating method is usually performed on the mineral

text: zircon

text: . The mineral incorporates

text: uranium

text: and

text: thorium

text: atom

text: s into its crystalline structure, but strongly rejects

text: lead

text: . Therefore, one can assume that the entire lead content of the zircon is

text: radiogenic

text: , i.e. it is produced solely by a process of

text: radioactive decay

text: after the formation of the mineral. Thus the current ratio of lead to uranium in the mineral can be used to determine its age.

answers: NDQ_005711

answers: current ratio of lead to uranium

answers: NDQ_005712

answers: zircon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: zircon

answers: NDQ_005715

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: current ratio of lead to uranium

answers: NDQ_005718

answers: it is produced solely by a process of radioactive decay after the formation of the mineral

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: the current ratio of lead to uranium

answers: NDQ_005712

answers: the current ratio of lead to uranium in the mineral

answers: NDQ_005713

answers: the current ratio of lead to uranium

answers: NDQ_005714

answers: the current ratio of lead to uranium

answers: NDQ_005715

answers: lead.

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: the current ratio of lead to uranium

answers: NDQ_005718

answers: lead.

answers: NDQ_005719

answers: zircon.

answers: NDQ_005720

answers: the current ratio of lead to uranium

text: Priabona is known from a compression-impression fossil preserved in fine shale of the Florissant formation in Colorado.  The formation is composed of successive lake deposits which have preserved a diverse assemblage of insects.  The insects and plants suggest a climate similar to modern Southeastern North America, with a number of taxa represented that are now found in the subtropics to tropics and confined to the Old World.  When Priabona was described, the Florissant formation was considered to be Miocene in age, based on the flora and fauna preserved.  Subsequent research and fossil descriptions permitted a re-examined dating, and by 1985 the formation had been reassigned to an Oligocene age.  Further refinement of the formation's age using radiometric dating of sanidine crystals has resulted in an age of 34 million years, which places the formation in the Late Eocene Priabonian stage.

text: Priabona is known from a

text: compression-impression fossil

text: preserved in fine

text: shale

text: of the

entity_name: Florissant Fossil Beds National Monument

text: Florissant formation

text: in Colorado.  The formation is composed of successive lake deposits which have preserved a diverse assemblage of insects.  The insects and plants suggest a climate similar to modern Southeastern North America, with a number of taxa represented that are now found in the subtropics to tropics and confined to the Old World.  When Priabona was described, the Florissant formation was considered to be

text: Miocene

text: in age, based on the flora and fauna preserved.  Subsequent research and fossil descriptions permitted a re-examined dating, and by 1985 the formation had been reassigned to an

text: Oligocene

text: age.  Further refinement of the formation's age using radiometric dating of

text: sanidine crystals

text: has resulted in an age of 34 million years, which places the formation in the Late Eocene

text: Priabonian

text: stage.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Oligocene

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: sanidine crystals

answers: NDQ_005715

answers: How long does carbon-14 decay?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Further refinement of the formation's age using radiometric dating of sanidine crystals

answers: NDQ_005718

answers: age of 34 million years

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: sanidine crystals

answers: NDQ_005712

answers: sanidine crystals

answers: NDQ_005713

answers: sanidine crystals

answers: NDQ_005714

answers: radiometric dating of sanidine crystals

answers: NDQ_005715

answers: 34 million years,

answers: NDQ_005716

answers: radiometric dating of sanidine crystals

answers: NDQ_005717

answers: radiometric dating of sanidine crystals

answers: NDQ_005718

answers: sanidine crystals

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Marmyan is known from the holotype specimen, collection number BMNH In. 20160(1), which along several other insects of different orders, are inclusions in a transparent chunk of Burmese amber.  As of 2004, the type insect was part of the amber collections housed at the British Museum of Natural History, London, England.  The amber specimen was recovered from deposits exposed in the Hukawng Valley of Kachin State, Myanmar.  Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 99 million years old, close to the Aptian – Cenomanian boundary.

text: Marmyan is known from the

text: holotype

text: specimen, collection number BMNH In. 20160(1), which along several other insects of different orders, are

text: inclusion

text: s in a transparent chunk of Burmese amber.  As of 2004, the type insect was part of the amber collections housed at the

text: British Museum of Natural History

text: London, England

text: .  The

text: amber

text: specimen was recovered from deposits exposed in the

text: Hukawng Valley

text: of

text: Kachin State

text: , Myanmar.  Burmese amber has been

text: radiometrically dated

text: using

text: U

text: Pb

text: isotopes, yielding an age of approximately 99 million years old, close to the

text: Aptian

text: Cenomanian

text: boundary.

answers: NDQ_005711

answers: radioactive isotopes

answers: NDQ_005712

answers: unanswerable

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: U-Pb isotopes

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: yielding an age of approximately 99 million years old

answers: NDQ_005718

answers: age of approximately 99 million years old

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: U-Pb isotopes,

answers: NDQ_005712

answers: U-Pb isotopes,

answers: NDQ_005713

answers: U-Pb isotopes,

answers: NDQ_005714

answers: U-Pb isotopes,

answers: NDQ_005715

answers: 99

answers: NDQ_005716

answers: radiometrically dated using U-Pb isotopes,

answers: NDQ_005717

answers: U-Pb isotopes,

answers: NDQ_005718

answers: close to the Aptian – Cenomanian boundary.

answers: NDQ_005719

answers: U-Pb isotopes,

answers: NDQ_005720

answers: U-Pb isotopes,

text: - Episode dated 18 March 2009  - Episode dated 20 March 2009   - Episode dated 3 April 2009 - Episode dated 23 April 2009 - Episode dated 27 April 2009   - Episode dated 17 August 2009  - Episode dated 19 August 2009   - Episode dated 20 August 2009   - Episode dated 27 August 2009- Episode dated 3 September 2009- Episode dated 10 September 2009- Episode dated 12 October 2009- Episode dated 16 October 2009- Episode dated 2 December 2009- Episode dated 28 January 2010- Episode dated 7 April 2010- Episode dated 28 April 2010- Episode dated 29 June 2010

text: - Episode dated 18 March 2009  - Episode dated 20 March 2009   - Episode dated 3 April 2009 - Episode dated 23 April 2009 - Episode dated 27 April 2009   - Episode dated 17 August 2009  - Episode dated 19 August 2009   - Episode dated 20 August 2009   - Episode dated 27 August 2009- Episode dated 3 September 2009- Episode dated 10 September 2009- Episode dated 12 October 2009- Episode dated 16 October 2009- Episode dated 2 December 2009- Episode dated 28 January 2010- Episode dated 7 April 2010- Episode dated 28 April 2010- Episode dated 29 June 2010

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: description

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: Episode dated 20 March 2009

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: - Episode dated 18 March 2009

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: Episode dated 18 March 2009

answers: NDQ_005720

answers: Episode dated 20 March 2009

answers: NDQ_005711

answers: 27 April 2009

answers: NDQ_005712

answers: 27 April 2009

answers: NDQ_005713

answers: 23 April 2009 - Episode dated 27 April 2009

answers: NDQ_005714

answers: 27 April 2009

answers: NDQ_005715

answers: 23 April 2009 - Episode dated 27 April 2009

answers: NDQ_005716

answers: 23 April 2009 - Episode dated 27 April 2009

answers: NDQ_005717

answers: 17 August 2009

answers: NDQ_005718

answers: - Episode dated 18 March 2009 - Episode dated 20 March 2009

answers: NDQ_005719

answers: 23 April 2009 - Episode dated 27 April 2009

answers: NDQ_005720

answers: 23 April 2009 - Episode dated 27 April 2009

text: Another example of short-lived extinct radionuclide dating is the Al – Mg chronometer, which can be used to estimate the relative ages of chondrules. Al decays to Mg with a half-life of 720 000 years. The dating is simply a question of finding the deviation from the natural abundance of Mg (the product of Al decay) in comparison with the ratio of the stable isotopes Al/Mg.

text: Another example of short-lived extinct radionuclide dating is the

text: Al

text: – Mg chronometer, which can be used to estimate the relative ages of

text: chondrules

text: . Al decays to Mg with a

text: half-life

text: of 720 000 years. The dating is simply a question of finding the deviation from the

text: natural abundance

text: of Mg (the product of Al decay) in comparison with the ratio of the stable isotopes Al/Mg.

answers: NDQ_005711

answers: radionuclide

answers: NDQ_005712

answers: Al decays to Mg

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Al decays to Mg with a half-life of 720 000

answers: NDQ_005715

answers: NDQ_005716

answers: Al decay

answers: NDQ_005717

answers: half-life of 720 000 years

answers: NDQ_005718

answers: half-life

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: finding the deviation from the natural abundance of Mg

answers: NDQ_005712

answers: short-lived extinct

answers: NDQ_005713

answers: Al – Mg chronometer,

answers: NDQ_005714

answers: short-lived extinct radionuclide

answers: NDQ_005715

answers: 720 000 years.

answers: NDQ_005716

answers: natural abundance of Mg

answers: NDQ_005717

answers: finding the deviation from the natural abundance of Mg

answers: NDQ_005718

answers: half-life of 720 000 years.

answers: NDQ_005719

answers: Al – Mg chronometer,

answers: NDQ_005720

answers: Al – Mg chronometer,

text: Libby and James Arnold proceeded to test the radiocarbon dating theory by analyzing samples with known ages. For example, two samples taken from the tombs of two Egyptian kings, Zoser and Sneferu, independently dated to 2625 BC plus or minus 75 years, were dated by radiocarbon measurement to an average of 2800 BC plus or minus 250 years. These results were published in Science in 1949. Within 11 years of their announcement, more than 20 radiocarbon dating laboratories had been set up worldwide.

text: Libby and

text: James Arnold

text: proceeded to test the radiocarbon dating theory by analyzing samples with known ages. For example, two samples taken from the tombs of two Egyptian kings,

text: Zoser

text: and

text: Sneferu

text: , independently dated to 2625 BC plus or minus 75 years, were dated by radiocarbon measurement to an average of 2800 BC plus or minus 250 years. These results were published in Science in 1949. Within 11 years of their announcement, more than 20 radiocarbon dating laboratories had been set up worldwide.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon measurement

answers: NDQ_005718

answers: sample with known ages

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: known ages.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating theory by analyzing samples with known ages.

answers: NDQ_005715

answers: 2800 BC plus or minus 250 years.

answers: NDQ_005716

answers: known ages.

answers: NDQ_005717

answers: 2800 BC plus or minus 250 years.

answers: NDQ_005718

answers: analyzing samples with known ages.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: 2800 BC plus or minus 250 years.

text: Gonzalez initially felt that the footprint marks could be differentiated from old quarry marks. Argon-Argon dating may be contaminated by olivine including older argon. Xenocrysts and phenocrysts were removed in a later dating of the ash material by Mark et al. 2010, which confirmed Renne's proposed age for the Xalnene Tuff. A re-examination of whether the features were footprints was conducted by Morse et al. 2010. A comparison with other markings thought to be footprints was undertaken, from various species of humans and in varying substrates and ages. This suggested that the marks were made by recent mining activity using picks. "The picks produce a spalling effect which removes material more widely around the point of impact,' says Morse. 'Actual pick marks are visible in the quarry but this spalling seems to have caused the print-like depressions with their 'mid-foot' deep points.'"

text: Gonzalez initially felt that the footprint marks could be differentiated from old quarry marks. Argon-Argon dating may be contaminated by

text: olivine

text: including older argon. Xenocrysts and phenocrysts were removed in a later dating of the ash material by Mark et al. 2010, which confirmed Renne's proposed age for the Xalnene Tuff. A re-examination of whether the features were footprints was conducted by Morse et al. 2010. A comparison with other markings thought to be footprints was undertaken, from various species of humans and in varying substrates and ages. This suggested that the marks were made by recent mining activity using picks. "The picks produce a spalling effect which removes material more widely around the point of impact,' says Morse. 'Actual pick marks are visible in the quarry but this spalling seems to have caused the print-like depressions with their 'mid-foot' deep points.'"

answers: NDQ_005711

answers: Argon-Argon dating

answers: NDQ_005712

answers: Argon-Argon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: argon

answers: NDQ_005717

answers: Argon-Argon dating may be contaminated by olivine

answers: NDQ_005718

answers: contaminated by olivine

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Argon-Argon

answers: NDQ_005712

answers: varying substrates and ages.

answers: NDQ_005713

answers: Argon-Argon dating

answers: NDQ_005714

answers: Argon-Argon dating may be contaminated by olivine

answers: NDQ_005715

answers: Argon-Argon

answers: NDQ_005716

answers: Argon-Argon

answers: NDQ_005717

answers: Argon-Argon dating may be contaminated by olivine

answers: NDQ_005718

answers: contaminated by olivine

answers: NDQ_005719

answers: Argon-Argon dating may be contaminated by olivine

answers: NDQ_005720

answers: Argon-Argon dating

text: Orontium wolfei has been identified from a group of exposures of the Allenby Formation and a group of exposures of the related Klondike Mountain Formation.  The type locality is at the "One mile Creek" exposure of the Allenby Formation near Princeton, British Columbia and additional fossils have been recovered from the Lamont Creek site near Princeton. The Allenby Formation is currently considered to be Early Eocene in age, based on Potassium–argon radiometric dating of plagioclase and biotite crystals.  The second group of fossils have been recovered from three outcrops of the early to early Middle Eocene Klondike Mountain Formation around Republic, Washington.  Fossils in the Klondike Mountain Formation are found in mudstone and shale layers of the lower part of the formation.  The lakes which produced these fossils are estimated to have been active between 48 and 49 million years ago, with the lava flows in the formation dating between 42 and 50 million years old.  Fossils of O. wolfei found in the Klondike Mountain Formation have been noted, prior to the species description, as belonging to the extinct morphogenus Zingiberopsis in collections and publications.  Zingiberopsis is a form taxon for Upper Cretaceous to Oligocene fossil leaves found in Western North America which are related to the modern Zingiberales, a plant order which includes modern bananas and gingers.   This identification was made by Jack A. Wolfe for specimens in the paleobotanical collection of the Burke Museum, Seattle, Washington.

text: Orontium wolfei has been identified from a group of exposures of the

text: Allenby Formation

text: and a group of exposures of the related

text: Klondike Mountain Formation

text: .  The

text: type locality

text: is at the "One mile Creek" exposure of the Allenby Formation near

text: Princeton, British Columbia

text: and additional fossils have been recovered from the Lamont Creek site near Princeton. The Allenby Formation is currently considered to be Early Eocene in age, based on

text: Potassium–argon

text: radiometric dating

text: of

text: plagioclase

text: and

text: biotite

text: crystals.  The second group of fossils have been recovered from three outcrops of the early to early Middle Eocene Klondike Mountain Formation around

text: Republic, Washington

text: .  Fossils in the Klondike Mountain Formation are found in

text: mudstone

text: and

text: shale

text: layers of the lower part of the formation.  The lakes which produced these fossils are estimated to have been active between 48 and 49 million years ago, with the lava flows in the formation dating between 42 and 50 million years old.  Fossils of O. wolfei found in the Klondike Mountain Formation have been noted, prior to the species description, as belonging to the extinct

text: morphogenus

text: Zingiberopsis

text: in collections and publications.  Zingiberopsis is a form taxon for

text: Upper Cretaceous

text: to

text: Oligocene

text: fossil leaves found in Western North America which are related to the modern

text: Zingiberales

text: , a plant order which includes modern bananas and gingers.   This identification was made by

text: Jack A. Wolfe

text: for specimens in the paleobotanical collection of the

text: Burke Museum

text: Seattle, Washington

answers: NDQ_005711

answers: potassium–argon

answers: NDQ_005712

answers: Early Eocene in age

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: potassium–argon radiometric dating

answers: NDQ_005715

answers: Potassium–argon radiometric dating

answers: NDQ_005716

answers: argon radiometric dating

answers: NDQ_005717

answers: plagioclase and biotite crystals

answers: NDQ_005718

answers: Potassium–argon

answers: NDQ_005719

answers: It's impossible to say

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium–argon

answers: NDQ_005712

answers: Potassium–argon

answers: NDQ_005713

answers: Potassium–argon

answers: NDQ_005714

answers: Potassium–argon radiometric dating

answers: NDQ_005715

answers: Zingiberopsis

answers: NDQ_005716

answers: Potassium–argon radiometric dating

answers: NDQ_005717

answers: The Allenby Formation is currently considered to be Early Eocene

answers: NDQ_005718

answers: Potassium–argon

answers: NDQ_005719

answers: Potassium–argon radiometric dating

answers: NDQ_005720

answers: Klondike Mountain Formation

text: Radiometric dating of lava flows has been used to establish a geomagnetic polarity time scale, part of which is shown in the image. This forms the basis of magnetostratigraphy, a geophysical correlation technique that can be used to date both sedimentary and volcanic sequences as well as the seafloor magnetic anomalies.

text: Radiometric dating

text: of lava flows has been used to establish a geomagnetic polarity time scale, part of which is shown in the image. This forms the basis of

text: magnetostratigraphy

text: , a geophysical correlation technique that can be used to date both sedimentary and volcanic sequences as well as the seafloor magnetic anomalies.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: magnetic anomalies

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: magnetostratigraphy

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: geomagnetic polarity time scale,

answers: NDQ_005712

answers: sedimentary and volcanic sequences

answers: NDQ_005713

answers: magnetostratigraphy,

answers: NDQ_005714

answers: magnetostratigraphy,

answers: NDQ_005715

answers: magnetostratigraphy,

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: magnetostratigraphy,

answers: NDQ_005718

answers: geomagnetic polarity time scale,

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: magnetostratigraphy,

text: In December 2015 Professor François Déroche of the Collège de France confirmed the identification of the two Birmingham leaves with those of the Paris Qur'an BnF Arabe 328(c), as had been proposed by Dr Alba Fedeli. Prof. Deroche expressed reservations about the reliability of the radiocarbon dates proposed for the Birmingham leaves, noting instances elsewhere in which radiocarbon dating had proved inaccurate in testing Qur'ans with an explicit endowment date; and also that none of the counterpart Paris leaves had yet been carbon-dated. Jamal bin Huwareib, managing director of the Mohammed bin Rashid Al Maktoum Foundation, has proposed that, were the radiocarbon dates to be confirmed, the Birmingham/Paris Qur'an might be identified with the text known to have been assembled by the first Caliph Abu Bakr, between 632 CE and 634 CE.

text: In December 2015 Professor

text: François Déroche

text: of the

text: Collège de France

text: confirmed the identification of the two Birmingham leaves with those of the Paris Qur'an BnF Arabe 328(c), as had been proposed by Dr Alba Fedeli. Prof. Deroche expressed reservations about the reliability of the radiocarbon dates proposed for the Birmingham leaves, noting instances elsewhere in which radiocarbon dating had proved inaccurate in testing Qur'ans with an explicit endowment date; and also that none of the counterpart Paris leaves had yet been carbon-dated. Jamal bin Huwareib, managing director of the Mohammed bin Rashid Al Maktoum Foundation, has proposed that, were the radiocarbon dates to be confirmed, the Birmingham/Paris Qur'an might be identified with the text known to have been assembled by the first

text: Caliph

text: Abu Bakr

text: , between 632 CE and 634 CE.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating had proved inaccurate

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: none of the counterpart Paris leaves had yet been carbon-dated

answers: NDQ_005718

answers: none of the counterpart Paris leaves had yet been carbon-dated

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: explicit endowment date;

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: inaccurate in testing Qur'ans with an explicit endowment date;

answers: NDQ_005715

answers: 632 CE and 634 CE.

answers: NDQ_005716

answers: endowment date;

answers: NDQ_005717

answers: inaccurate in testing Qur'ans with an explicit endowment date;

answers: NDQ_005718

answers: inaccurate in testing Qur'ans with an explicit endowment date;

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: The Saksunarvatn tephra via radiocarbon dating is ca 10,200 years BP.

text: The Saksunarvatn tephra via

text: radiocarbon dating

text: is ca 10,200 years BP.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon is a noble element

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 10,200 years BP.

answers: NDQ_005716

answers: radiocarbon dating is ca 10,200 years BP.

answers: NDQ_005717

answers: radiocarbon dating is ca 10,200 years BP.

answers: NDQ_005718

answers: radiocarbon dating is ca 10,200 years BP.

answers: NDQ_005719

answers: radiocarbon dating is ca 10,200 years BP.

answers: NDQ_005720

answers: radiocarbon dating is ca 10,200 years BP.

text: There were different types of dating used at Gogo Falls.  They found small samples of charcoal which were sent to the University of Oxford to be dated using radiocarbon dating techniques.  However, the samples of charcoal found were less than 30g, which meant the dates were only average dates because the samples were smaller than what was needed to obtain an exact date.  The samples were not able to give exact dates because they could have come from the levels above or below the level that was being dated.  Even though the samples had minor problems for obtaining dates, they were the best option for dates in those levels.  However, there were items that were dated using this method that did support the understanding of the site.  The dates found did not always match the stratigraphy but the dates themselves were not statistically different. The other technique used to date items in Gogo Falls was  obsidian hydration.  For the excavations in 1983, J.W. Michele performed the obsidian hydration dating at MOHLAB.  There were also problems with this kind of dating because rates of hydration are not always constant enough to date correctly.  The date of an item could change based on how much sunlight that it receives and the chemical composition that is in its environment.  Some dates of samples that were found did not match because there was a 1500-year gap between the two and some of the other dates were older than the ones that were found in deeper layers.  However, there were other dates that showed stratigraphic consistency because there were layers in the trenches that showed the deeper levels were older than the ones above it. The dates that were attained from the excavations date to about 2000 BP and range between the years of 1510-990 BC and AD 4 and AD 410.

text: There were different types of dating used at Gogo Falls.  They found small samples of charcoal which were sent to the

text: University of Oxford

text: to be dated using

text: radiocarbon dating

text: techniques.  However, the samples of charcoal found were less than 30g, which meant the dates were only average dates because the samples were smaller than what was needed to obtain an exact date.  The samples were not able to give exact dates because they could have come from the levels above or below the level that was being dated.  Even though the samples had minor problems for obtaining dates, they were the best option for dates in those levels.  However, there were items that were dated using this method that did support the understanding of the site.  The dates found did not always match the

text: stratigraphy

text: but the dates themselves were not statistically different. The other technique used to date items in Gogo Falls was

text: obsidian hydration

text: .  For the excavations in 1983, J.W. Michele performed the obsidian hydration dating at MOHLAB.  There were also problems with this kind of dating because rates of hydration are not always constant enough to date correctly.  The date of an item could change based on how much sunlight that it receives and the chemical composition that is in its environment.  Some dates of samples that were found did not match because there was a 1500-year gap between the two and some of the other dates were older than the ones that were found in deeper layers.  However, there were other dates that showed stratigraphic consistency because there were layers in the trenches that showed the deeper levels were older than the ones above it. The dates that were attained from the excavations date to about 2000 BP and range between the years of 1510-990 BC and AD 4 and AD 410.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: How long does carbon-14 decay?

answers: NDQ_005716

answers: hydration dating

answers: NDQ_005717

answers: rates of hydration are not always constant enough to date correctly

answers: NDQ_005718

answers: The date of an item could change based on how much sunlight that it receives

answers: NDQ_005719

answers: Which dating method is used for very young materials?

answers: NDQ_005720

answers: NDQ_005711

answers: chemical composition that is in its environment.

answers: NDQ_005712

answers: 1510-990 BC and AD 4 and AD 410.

answers: NDQ_005713

answers: rates of hydration are not always constant enough to date correctly.

answers: NDQ_005714

answers: chemical composition that is in its environment.

answers: NDQ_005715

answers: 2000 BP

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 1510-990 BC and AD 4 and AD 410.

answers: NDQ_005718

answers: Some dates of samples that were found did not match

answers: NDQ_005719

answers: The date of an item could change based on how much sunlight

answers: NDQ_005720

answers: rates of hydration are not always constant enough to date correctly.

text: The Kayenta Formation is part of the Glen Canyon Group that includes formations not only in northern Arizona but also parts of southeastern Utah, western Colorado, and northwestern New Mexico. It is composed mostly of two facies, one dominated by silty deposition and the other dominated by sandstone. The siltstone facies is found in much of Arizona, while the sandstone facies is present in areas of northern Arizona, southern Utah, western Colorado, and northwestern New Mexico. The formation was primarily deposited by rivers, with the silty facies as the slower, more sluggish part of the river system. Kayenta Formation deposition was ended by the encroaching dune field that would become the Navajo Sandstone. A definitive radiometric dating of this formation has not yet been made, and the available stratigraphic correlation has been based on a combination of radiometric dates from vertebrate fossils, magnetostratigraphy and pollen evidence. It has been surmised that the Kayenta Formation was deposited during the Sinemurian and Pliensbachian stages of the Early Jurassic Period or approximately 196 to 183 million years ago.

text: The Kayenta Formation is part of the Glen Canyon Group that includes formations not only in northern Arizona but also parts of southeastern Utah, western Colorado, and northwestern New Mexico. It is composed mostly of two

text: facies

text: , one dominated by

text: silt

text: y deposition and the other dominated by

text: sandstone

text: . The siltstone facies is found in much of Arizona, while the sandstone facies is present in areas of northern Arizona, southern Utah, western Colorado, and northwestern New Mexico. The formation was primarily deposited by rivers, with the silty facies as the slower, more sluggish part of the river system. Kayenta Formation deposition was ended by the encroaching dune field that would become the

text: Navajo Sandstone

text: . A definitive radiometric dating of this formation has not yet been made, and the available stratigraphic correlation has been based on a combination of radiometric dates from vertebrate fossils, magnetostratigraphy and pollen evidence. It has been surmised that the Kayenta Formation was deposited during the

text: Sinemurian

text: and

text: Pliensbachian

text: stages of the Early Jurassic Period or approximately 196 to 183 million years ago.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: vertebrate fossils

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 196 to 183 million years ago

answers: NDQ_005718

answers: A definitive radiometric dating

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: vertebrate fossils,

answers: NDQ_005712

answers: vertebrate fossils,

answers: NDQ_005713

answers: 196 to 183 million years ago.

answers: NDQ_005714

answers: vertebrate fossils,

answers: NDQ_005715

answers: 196 to 183 million years ago.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: A definitive radiometric dating of this formation has not yet been made,

answers: NDQ_005718

answers: A definitive radiometric dating of this formation has not yet been made,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: 196 to 183 million years ago.

text: In 1964 a radiocarbon date put the statue's age at 350 years. A more recent radiocarbon dating estimates the wood to date from between 1440 to 1600 CE, although this does not mean it was carved at this time. It could have been carved at any time after this.

text: In 1964 a radiocarbon date put the statue's age at 350 years. A more recent

text: radiocarbon dating

text: estimates the wood to date from between 1440 to 1600

text: CE

text: , although this does not mean it was carved at this time. It could have been carved at any time after this.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: it is based on carbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: this does not mean it was carved at this time

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: between 1440 to 1600 CE,

answers: NDQ_005713

answers: 1440 to 1600 CE,

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 1440 to 1600 CE,

answers: NDQ_005716

answers: radiocarbon date put the statue's age at 350 years.

answers: NDQ_005717

answers: between 1440 to 1600 CE,

answers: NDQ_005718

answers: this does not mean it was carved at this time.

answers: NDQ_005719

answers: 1440 to 1600 CE,

answers: NDQ_005720

answers: 1440 to 1600 CE,

text: Radiocarbon dating is also simply called Carbon-14 dating. Carbon-14 is a radioactive isotope of carbon, with a half-life of 5,730 years, (which is very short compared with the above isotopes) and decays into nitrogen. In other radiometric dating methods, the heavy parent isotopes were produced by nucleosynthesis in supernovas, meaning that any parent isotope with a short half-life should be extinct by now. Carbon-14, though, is continuously created through collisions of neutrons generated by cosmic rays with nitrogen in the upper atmosphere and thus remains at a near-constant level on Earth. The carbon-14 ends up as a trace component in atmospheric carbon dioxide (CO).

text: Radiocarbon dating

text: is also simply called Carbon-14 dating. Carbon-14 is a radioactive isotope of carbon, with a half-life of 5,730 years, (which is very short compared with the above isotopes) and decays into nitrogen. In other radiometric dating methods, the heavy parent isotopes were produced by

text: nucleosynthesis

text: in supernovas, meaning that any parent isotope with a short half-life should be extinct by now. Carbon-14, though, is continuously created through collisions of neutrons generated by

text: cosmic rays

text: with nitrogen in the upper

text: atmosphere

text: and thus remains at a near-constant level on Earth. The carbon-14 ends up as a trace component in atmospheric

text: carbon dioxide

text: (CO).

answers: NDQ_005711

answers: Radiocarbon dating

answers: NDQ_005712

answers: carbon-14 is continuously created

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays into nitrogen

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: Carbon-14 ends up as a trace component in atmospheric carbon dioxide (CO)

answers: NDQ_005718

answers: any parent isotope with a short half-life should be extinct by now

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: nucleosynthesis in supernovas,

answers: NDQ_005712

answers: Carbon-14,

answers: NDQ_005713

answers: Carbon-14 dating.

answers: NDQ_005714

answers: Carbon-14, though, is continuously created through collisions of neutrons

answers: NDQ_005715

answers: nitrogen.

answers: NDQ_005716

answers: decays into nitrogen.

answers: NDQ_005717

answers: Carbon-14, though, is continuously created through collisions of neutrons

answers: NDQ_005718

answers: the heavy parent isotopes

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Carbon-14 dating.

text: Afropone oculata was described from two fossils, the holotype specimen number BP/2/28072a/2, identified as a female, and an additional poorly preserved fossil, number BP/2/26631-17. Afropone (?) orapa was based on a single holotype male, specimen BP/2/26628/1, and tentatively placed into the genus based on overall morphology.  The specimens are mostly complete with variation in the quantity of detail, and are preserved as compression fossils in shale. The shales and mudstones of the Orapa site were rapidly deposited in a crater lake formed as the result of a large volcanic eruption in the Cretaceous. The sediment originated as an epiclastic kimberlite and derives from rapid weathering and decomposition of the sides of the kimberlite crater. Of the four major sedimentation types that have been observe at Orapa, fossils are found in only two, the granular mass flows and the fine-grained sediments:  woody debris fossils are found in the granular mass flows, but well-preserved fossils are only recovered in the fine-grained sediments. The fossil-bearing stratum was uncovered during mining of the underlying diamond-bearing rocks at the site.  Radiometric dating of the kimberlite pipe reported in 1977 gave an age in the general range of .  Further dating utilizing zircon crystals reported on in 2004 gave more defined age of approximately  placing the date in the Turonian age of the late Cretaceous.

text: Afropone oculata was described from two fossils, the

text: holotype

text: specimen number BP/2/28072a/2, identified as a female, and an additional poorly preserved fossil, number BP/2/26631-17. Afropone (?) orapa was based on a single holotype male, specimen BP/2/26628/1, and tentatively placed into the genus based on overall morphology.  The specimens are mostly complete with variation in the quantity of detail, and are preserved as compression fossils in shale. The shales and mudstones of the Orapa site were rapidly deposited in a

text: crater lake

text: formed as the result of a large volcanic eruption in the Cretaceous. The sediment originated as an epiclastic

text: kimberlite

text: and derives from rapid weathering and decomposition of the sides of the kimberlite crater. Of the four major sedimentation types that have been observe at Orapa, fossils are found in only two, the granular mass flows and the fine-grained sediments:  woody debris fossils are found in the granular mass flows, but well-preserved fossils are only recovered in the fine-grained sediments. The fossil-bearing stratum was uncovered during mining of the underlying

text: diamond-bearing rocks at the site

text: Radiometric dating

text: of the kimberlite pipe reported in 1977 gave an age in the general range of .  Further dating utilizing zircon crystals reported on in 2004 gave more defined age of approximately  placing the date in the

text: Turonian age

text: of the late Cretaceous.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: zircon crystals

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: zircon crystals

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: further dating utilizing zircon crystals reported on in 2004 gave more defined age

answers: NDQ_005718

answers: zircon crystals

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: zircon crystals

answers: NDQ_005712

answers: Turonian age of the late Cretaceous.

answers: NDQ_005713

answers: woody debris fossils

answers: NDQ_005714

answers: granular mass flows,

answers: NDQ_005715

answers: Cretaceous.

answers: NDQ_005716

answers: decomposition

answers: NDQ_005717

answers: zircon crystals

answers: NDQ_005718

answers: variation in the quantity of detail,

answers: NDQ_005719

answers: granular mass flows and the fine-grained sediments:

answers: NDQ_005720

answers: Turonian age of the late Cretaceous.

text: The Adare Peninsula consists of overlapping shield volcanoes that have been potassium–argon dated 6 to 13 million years old. Potassium–argon dates of 2.27 million years and perhaps 1.14 million years have also been obtained.

text: The Adare Peninsula consists of overlapping

text: shield volcano

text: es that have been

text: potassium–argon dated

text: 6 to 13 million years old. Potassium–argon dates of 2.27 million years and perhaps 1.14 million years have also been obtained.

answers: NDQ_005711

answers: potassium–argon

answers: NDQ_005712

answers: potassium–argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 6 to 13 million years old

answers: NDQ_005718

answers: potassium–argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium–argon

answers: NDQ_005712

answers: 6 to 13 million years old.

answers: NDQ_005713

answers: 6 to 13 million years old.

answers: NDQ_005714

answers: potassium–argon

answers: NDQ_005715

answers: 6 to 13 million years old. Potassium–argon

answers: NDQ_005716

answers: potassium–argon

answers: NDQ_005717

answers: 6 to 13 million years old.

answers: NDQ_005718

answers: potassium–argon dated 6 to 13 million years old.

answers: NDQ_005719

answers: 6 to 13 million years old.

answers: NDQ_005720

answers: potassium–argon

text: In 1926, he was appointed as Head of the Meteorological Department of the National Observatory, Athens. In 1928, he was elected Professor of Meteorology and Climatology at the Department of Physics and Mathematics, Aristotle University of Thessaloniki, Greece. In 1935 he was appointed as Director of the National Observatory, Athens. In 1939 he was invited as honorary Professor to the Chair of Meteorology at the University of Athens. At the same time he takes over the management of the Meteorological Institute of the National Observatory, Athens. When World War II was declared, Professor Mariolopoulos has served as a major in the Greek Air Force, assuming command of an echelon of officer-meteorologists at the Air Force headquarters. At the National Observatory, Athens, Mariolopoulos was particularly active and, for the first time in Greece, he established a service for the measurement of Atmospheric Electricity, set up a special Radiometric Station on Mt. Hymettus, as an annex of the National Observatory, Athens while at the University of Athens he supervised dozens of doctoral dissertations.

text: In 1926, he was appointed as Head of the Meteorological Department of the National Observatory, Athens. In 1928, he was elected Professor of Meteorology and Climatology at the Department of Physics and Mathematics, Aristotle University of Thessaloniki, Greece. In 1935 he was appointed as Director of the National Observatory, Athens. In 1939 he was invited as honorary Professor to the Chair of Meteorology at the University of Athens. At the same time he takes over the management of the Meteorological Institute of the National Observatory, Athens. When World War II was declared, Professor Mariolopoulos has served as a major in the Greek Air Force, assuming command of an echelon of officer-meteorologists at the Air Force headquarters. At the National Observatory, Athens, Mariolopoulos was particularly active and, for the first time in Greece, he established a service for the measurement of Atmospheric Electricity, set up a special Radiometric Station on Mt. Hymettus, as an annex of the National Observatory, Athens while at the University of Athens he supervised dozens of doctoral dissertations.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Professor Mariolopoulos has served as a major in the Greek Air Force,

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Atmospheric Electricity,

answers: NDQ_005712

answers: Atmospheric Electricity,

answers: NDQ_005713

answers: Radiometric Station on Mt. Hymettus,

answers: NDQ_005714

answers: Atmospheric Electricity,

answers: NDQ_005715

answers: Aristotle University of Thessaloniki,

answers: NDQ_005716

answers: Atmospheric Electricity,

answers: NDQ_005717

answers: Radiometric Station on Mt. Hymettus,

answers: NDQ_005718

answers: dozens of doctoral dissertations.

answers: NDQ_005719

answers: dozens of doctoral dissertations.

answers: NDQ_005720

answers: Meteorology and Climatology

text: A number of radiocarbon-dates are known from the barrows:

text: A number of

text: radiocarbon-dates

text: are known from the barrows:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon is present

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon-dates

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon-dates

answers: NDQ_005712

answers: radiocarbon-dates

answers: NDQ_005713

answers: radiocarbon-dates are known from the barrows:

answers: NDQ_005714

answers: radiocarbon-dates are known from the barrows:

answers: NDQ_005715

answers: barrows:

answers: NDQ_005716

answers: radiocarbon-dates are known from the barrows:

answers: NDQ_005717

answers: radiocarbon-dates are known from the barrows:

answers: NDQ_005718

answers: radiocarbon-dates are known from the barrows:

answers: NDQ_005719

answers: A number of radiocarbon-dates are known from the barrows:

answers: NDQ_005720

answers: radiocarbon-dates are known from the barrows:

text: Stave churches can be dated in various ways: by historical records or inscriptions, by stylistic means using construction details or ornaments, or by dendrochronology and radiocarbon dating. Often historical records or inscriptions will point to a year when the church is known to have existed. Archaeological excavations can yield finds which can provide relative dating for the structure, whereas absolute dating methods such as radiocarbon dating and dendrochronology can provide a more exact date. One drawback of dendrochronology is that it tends to overlook the possibility that the wood could have been reused from an older structure, or felled and left for many years before use.

text: Stave churches can be dated in various ways: by historical records or inscriptions, by stylistic means using construction details or ornaments, or by

text: dendrochronology

text: and

text: radiocarbon dating

text: . Often historical records or inscriptions will point to a year when the church is known to have existed. Archaeological excavations can yield finds which can provide

text: relative dating

text: for the structure, whereas

text: absolute dating

text: methods such as radiocarbon dating and dendrochronology can provide a more exact date. One drawback of dendrochronology is that it tends to overlook the possibility that the wood could have been reused from an older structure, or felled and left for many years before use.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: radiocarbon dating is used for dating human remains

answers: NDQ_005715

answers: radiocarbon dating

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: absolute dating methods such as radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: can provide a more exact date.

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: absolute dating

answers: NDQ_005717

answers: dendrochronology can provide a more exact date.

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: absolute dating methods such as radiocarbon dating and dendrochronology

answers: NDQ_005720

answers: radiocarbon dating.

text: The Dryosaurus holotype specimen YPM 1876 was discovered in Reed’s YPM Quarry 5, in the Upper Brushy Basin Member, of the Morrison Formation.  In the Late Jurassic Morrison formation of Western North America, Dryosaurus remains have been recovered from stratigraphic zones 2-6. A spectacular digsite near Uravan, Colorado held hundreds of D. altus fossils which represented multiple stages of the animal's life cycle.  This formation is a sequence of shallow marine and alluvial sediments which, according to radiometric dating, ranges between 156.3 million years old (Ma) at its base, to 146.8 million years old at the top, which places it in the late Oxfordian, Kimmeridgian, and early Tithonian stages of the Late Jurassic period.  In 1877 this formation became the center of the Bone Wars, a fossil-collecting rivalry between early paleontologists Othniel Charles Marsh and Edward Drinker Cope.  The Morrison Formation is interpreted as a semiarid environment with distinct wet and dry seasons.  The Morrison Basin where dinosaurs lived, stretched from New Mexico to Alberta and Saskatchewan, and was formed when the precursors to the Front Range of the Rocky Mountains started pushing up to the west.  The deposits from their  east-facing drainage basins were carried by streams and rivers and deposited in swampy lowlands, lakes, river channels and floodplains.  This formation is similar in age to the Solnhofen Limestone Formation in Germany and the Tendaguru Formation in Tanzania.

text: The Dryosaurus

text: holotype

text: specimen YPM 1876 was discovered in Reed’s YPM Quarry 5, in the Upper Brushy Basin Member, of the

text: Morrison Formation

text: .  In the Late Jurassic Morrison formation of Western North America, Dryosaurus remains have been recovered from stratigraphic zones 2-6. A spectacular digsite near Uravan, Colorado held hundreds of D. altus fossils which represented multiple stages of the animal's life cycle.  This formation is a sequence of shallow marine and alluvial sediments which, according to

text: radiometric dating

text: , ranges between 156.3 million years old (

text: Ma

text: ) at its base, to 146.8 million years old at the top, which places it in the late

text: Oxfordian

text: Kimmeridgian

text: , and early

text: Tithonian

text: stages

text: of the Late Jurassic period.  In 1877 this formation became the center of the

text: Bone Wars

text: , a fossil-collecting rivalry between early paleontologists

text: Othniel Charles Marsh

text: and

text: Edward Drinker Cope

text: .  The Morrison Formation is interpreted as a

text: semiarid

text: environment with distinct

text: wet

text: and

text: dry season

text: s.  The Morrison Basin where dinosaurs lived, stretched from New Mexico to Alberta and Saskatchewan, and was formed when the precursors to the

text: Front Range

text: of the Rocky Mountains started pushing up to the west.  The deposits from their  east-facing

text: drainage basin

text: s were carried by streams and

text: river

text: s and deposited in

text: swamp

text: y lowlands, lakes, river channels and

text: floodplain

text: s.  This formation is similar in age to the

text: Solnhofen Limestone

text: Formation in

text: Germany

text: and the

text: Tendaguru Formation

text: in

text: Tanzania

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: this formation is interpreted as a semiarid environment

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating, ranges between 156.3 million years old

answers: NDQ_005718

answers: ranges between 156.3 million years old

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: NDQ_005711

answers: 156.3 million years old (Ma)

answers: NDQ_005712

answers: Late Jurassic period.

answers: NDQ_005713

answers: 156.3 million years old (Ma)

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: Morrison Formation.

answers: NDQ_005716

answers: radiometric dating,

answers: NDQ_005717

answers: 146.8 million years old at the top,

answers: NDQ_005718

answers: ranges between 156.3 million years old

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: Edward Drinker Cope.

text: This is important because the presence of the three mineral phases allows investigation of isotopic dates using samples that provide a great separation in concentrations between parent and daughter nuclides. This is particularly true of uranium and lead. Lead is strongly chalcophilic and is found in the sulfide at a much greater concentration than in the silicate, versus uranium. Because of this segregation in the parent and daughter nuclides during the formation of the meteorite, this allowed a much more precise date of the formation of the solar disk and hence the planets than ever before.

text: This is important because the presence of the three mineral phases allows investigation of isotopic dates using samples that provide a great separation in concentrations between parent and daughter nuclides. This is particularly true of uranium and lead. Lead is strongly

text: chalcophilic

text: and is found in the sulfide at a much greater concentration than in the silicate, versus uranium. Because of this segregation in the parent and daughter nuclides during the formation of the meteorite, this allowed a much more precise date of the formation of the solar disk and hence the planets than ever before.

answers: NDQ_005711

answers: isotopic

answers: NDQ_005712

answers: isotopic

answers: NDQ_005713

answers: NDQ_005714

answers: isotopic dating allows a much more precise date

answers: NDQ_005715

answers: NDQ_005716

answers: isotopic dating

answers: NDQ_005717

answers: isotopic

answers: NDQ_005718

answers: isotopic

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: isotopic

answers: NDQ_005712

answers: three mineral phases

answers: NDQ_005713

answers: a great separation in concentrations between parent and daughter nuclides.

answers: NDQ_005714

answers: a great separation in concentrations between parent and daughter nuclides.

answers: NDQ_005715

answers: lead.

answers: NDQ_005716

answers: separation in concentrations between parent and daughter nuclides.

answers: NDQ_005717

answers: a great separation in concentrations between parent and daughter nuclides.

answers: NDQ_005718

answers: Lead is strongly chalcophilic

answers: NDQ_005719

answers: uranium and lead.

answers: NDQ_005720

answers: uranium and lead.

text: This formal designation allowed radiometric dates to be obtained from samples across the globe that corresponded to the base of the Cambrian.  Early dates of  quickly gained favour, though the methods used to obtain this number are now considered to be unsuitable and inaccurate.  A more precise date using modern radiometric dating yield a date of . The ash horizon in Oman from which this date was recovered corresponds to a marked fall in the abundance of carbon-13 that correlates to equivalent excursions elsewhere in the world, and to the disappearance of distinctive Ediacaran fossils (Namacalathus,  Cloudina).  Nevertheless there are arguments that the dated horizon in Oman does not correspond to the Ediacaran-Cambrian boundary, but represents a facies change from marine to evaporite-dominated strata — which would mean that dates from other, more suitable sections, ranging from 544 or 542 Ma, are more suitable.

text: This formal designation allowed radiometric dates to be obtained from samples across the globe that corresponded to the base of the Cambrian.  Early dates of  quickly gained favour, though the methods used to obtain this number are now considered to be unsuitable and inaccurate.  A more precise date using modern radiometric dating yield a date of . The ash horizon in Oman from which this date was recovered corresponds to a marked fall in the abundance of

text: that correlates to equivalent excursions elsewhere in the world, and to the disappearance of distinctive Ediacaran fossils (Namacalathus,  Cloudina).  Nevertheless there are arguments that the dated horizon in Oman does not correspond to the Ediacaran-Cambrian boundary, but represents a facies change from marine to evaporite-dominated strata — which would mean that dates from other, more suitable sections, ranging from 544 or 542 Ma, are more suitable.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Cambrian

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Carbon-14 dating yield a date of

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 544 or 542 Ma

answers: NDQ_005718

answers: unsuitable and inaccurate

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: samples

answers: NDQ_005712

answers: Cambrian.

answers: NDQ_005713

answers: Cambrian.

answers: NDQ_005714

answers: carbon-13

answers: NDQ_005715

answers: carbon-13

answers: NDQ_005716

answers: carbon-13

answers: NDQ_005717

answers: carbon-13

answers: NDQ_005718

answers: inaccurate.

answers: NDQ_005719

answers: 544 or 542 Ma,

answers: NDQ_005720

answers: 544 or 542 Ma,

text: The base is not defined in the same way everywhere. In northern Germany the base is formed by the Calvörde Beds, in the Spessart and Odenwald by the base of the Heigenbrücken-Sandstone. Radiometric dating has shown the age of the Germanic Trias is not totally corresponding with the Triassic period. The base of the Buntsandstein was formed during the Changhsingian, the uppermost stage of the Permian, about . The top of the Keuper is Rhaetian in age and at about  at least a few million years older than the Triassic-Jurassic boundary. Usually there is a stratigraphic hiatus between the base of the Lias and top of the Germanic Trias.

text: The base is not defined in the same way everywhere. In northern Germany the base is formed by the

text: Calvörde Beds

text: , in the

text: Spessart

text: and

text: Odenwald

text: by the base of the

text: Heigenbrücken-Sandstone

text: Radiometric dating

text: has shown the age of the Germanic Trias is not totally corresponding with the Triassic period. The base of the Buntsandstein was formed during the

text: Changhsingian

text: , the uppermost

text: stage

text: of the Permian, about . The top of the Keuper is

text: Rhaetian

text: in age and at about  at least a few million years older than the Triassic-Jurassic boundary. Usually there is a

text: stratigraphic hiatus

text: between the base of the Lias and top of the Germanic Trias.

answers: NDQ_005711

answers: Radiometric dating

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: is not totally corresponding with the Triassic period

answers: NDQ_005718

answers: not totally corresponding with the Triassic period

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiometric dating

answers: NDQ_005712

answers: Usually there is a stratigraphic hiatus

answers: NDQ_005713

answers: Radiometric dating

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: Changhsingian,

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: Radiometric dating

answers: NDQ_005718

answers: not totally corresponding with the Triassic period.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: All methods based on the radioactive decay belong to this category. The principle at the base of radiometric dating is that natural unstable isotopes, called 'parent isotopes', decay to some isotope which is instead stable, called the 'daughter isotope'. Under the assumptions that (1) the initial amount of parent and daughter isotopes can be estimated, and (2) after the geologic material formed, parent and daughter isotopes did not escape the system, the age of the material can be obtained from the measurement of isotope concentrations, through the laws of radioactive decay.Methods of this kind are usually identified with the names of the parent/daughter elements. The radiometric methods under this category are:

text: All methods based on the

text: radioactive decay

text: belong to this category. The principle at the base of

text: radiometric dating

text: is that natural unstable

text: isotope

text: s, called 'parent isotopes', decay to some

text: isotope

text: which is instead stable, called the 'daughter isotope'. Under the assumptions that (1) the initial amount of parent and daughter isotopes can be estimated, and (2) after the geologic material formed, parent and daughter isotopes did not escape the system, the age of the material can be obtained from the measurement of isotope concentrations, through the laws of

text: radioactive decay

text: .Methods of this kind are usually identified with the names of the parent/daughter elements. The radiometric methods under this category are:

answers: NDQ_005711

answers: measurement of isotope concentrations

answers: NDQ_005712

answers: isotope concentrations

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: parent isotopes

answers: NDQ_005718

answers: the initial amount of parent and daughter isotopes can be estimated

answers: NDQ_005719

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: the measurement of isotope concentrations,

answers: NDQ_005712

answers: measurement of isotope concentrations,

answers: NDQ_005713

answers: radioactive decay

answers: NDQ_005714

answers: radioactive decay

answers: NDQ_005715

answers: radioactive decay

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: names of the parent/daughter elements.

answers: NDQ_005718

answers: parent and daughter isotopes did not escape the system,

answers: NDQ_005719

answers: radioactive decay

answers: NDQ_005720

answers: radioactive decay

text: Researchers have dated Olduvai Gorge layers with radiometric dating of the embedded artifacts, using potassium-argon and argon-argon methodology. Geologist Richard L. Hay studied the Olduvai Gorge and surrounding region between 1961 and 2002. His findings revealed that the site once contained a large lake, with shores covered by deposits of volcanic ash. Around 500,000 years ago, seismic activity diverted a nearby stream which proceeded to cut down through the sediments, revealing seven main layers in the walls of the gorge.

text: Researchers have dated Olduvai Gorge layers with

text: radiometric dating

text: of the embedded

text: artifact

text: s, using

text: potassium-argon

text: and

text: argon-argon

text: methodology. Geologist Richard L. Hay studied the Olduvai Gorge and surrounding region between 1961 and 2002. His findings revealed that the site once contained a large lake, with shores covered by deposits of

text: volcanic ash

text: . Around 500,000 years ago,

text: seismic activity

text: diverted a nearby stream which proceeded to cut down through the sediments, revealing seven main layers in the walls of the gorge.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: argon-argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: argon-argon

answers: NDQ_005718

answers: embedded artifacts

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon and argon-argon methodology.

answers: NDQ_005712

answers: potassium-argon and argon-argon

answers: NDQ_005713

answers: potassium-argon and argon-argon methodology.

answers: NDQ_005714

answers: potassium-argon and argon-argon

answers: NDQ_005715

answers: potassium-argon and argon-argon

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: potassium-argon

answers: NDQ_005718

answers: embedded artifacts,

answers: NDQ_005719

answers: argon-argon

answers: NDQ_005720

answers: potassium-argon and argon-argon

text: One of the advantages of this method is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a half-life of about 703 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample even if some of the lead has been lost.

text: One of the advantages of this method is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a

text: half-life

text: of about 703 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample even if some of the lead has been lost.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 decays to uranium

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: lead decay

answers: NDQ_005717

answers: lead-206

answers: NDQ_005718

answers: some of the lead has been lost

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-235's decay to lead-207

answers: NDQ_005712

answers: some of the lead has been lost.

answers: NDQ_005713

answers: any sample provides two clocks,

answers: NDQ_005714

answers: any sample provides two clocks,

answers: NDQ_005715

answers: uranium-235's decay to lead-207

answers: NDQ_005716

answers: lead has been lost.

answers: NDQ_005717

answers: any sample provides two clocks,

answers: NDQ_005718

answers: some of the lead has been lost.

answers: NDQ_005719

answers: 4.5 billion years,

answers: NDQ_005720

answers: 4.5 billion years,

text: Kardiasperma parvum has been identified from a single location in the Clarno Formation, the Clarno nut beds, type locality for both the formation and the species. The nut beds are approximately  east of the unincorporated community of Clarno, Oregon, and currently considered to be middle Eocene in age, based on averaging zircon fission track radiometric dating which yielded an age of 43.6 and 43.7 ± 10 million years ago and argon–argon dating radiometric dating which yielded a 36.38 ± 1.31 to 46.8 ± 3.36 Mya date. The average of the dates resulted in an age range of 45 to 43 Mya. The beds are composed of silica and calcium carbonate cemented tuffaceous sandstones, siltstones, and conglomerates which preserve either a lake delta environment, or alternatively periodic floods and volcanic mudflows preserved with hot spring activity.

text: Kardiasperma parvum has been identified from a single location in the

text: Clarno Formation

text: , the Clarno nut beds,

text: type locality

text: for both the formation and the species. The nut beds are approximately  east of the unincorporated community of

text: Clarno, Oregon

text: , and currently considered to be middle Eocene in age, based on averaging

text: zircon fission track

text: radiometric dating

text: which yielded an age of 43.6 and 43.7 ± 10

text: million years ago

text: and

text: argon–argon dating

text: radiometric dating

text: which yielded a 36.38 ± 1.31 to 46.8 ± 3.36 Mya date. The average of the dates resulted in an age range of 45 to 43 Mya. The beds are composed of silica and calcium carbonate cemented

text: tuff

text: aceous sandstones, siltstones, and conglomerates which preserve either a lake delta environment, or alternatively periodic floods and volcanic mudflows preserved with hot spring activity.

answers: NDQ_005711

answers: zircon fission track

answers: NDQ_005712

answers: zircon fission track

answers: NDQ_005713

answers: Yes

answers: NDQ_005714

answers: zircon fission track radiometric dating

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: argon–argon dating

answers: NDQ_005717

answers: 36.38  1.31 to 46.8  3.36 Mya date

answers: NDQ_005718

answers: an age range of 45 to 43 Mya

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: averaging zircon fission track

answers: NDQ_005712

answers: middle Eocene

answers: NDQ_005713

answers: argon–argon dating

answers: NDQ_005714

answers: argon–argon

answers: NDQ_005715

answers: argon–argon

answers: NDQ_005716

answers: calcium carbonate

answers: NDQ_005717

answers: 36.38

answers: NDQ_005718

answers: age range of 45 to 43 Mya.

answers: NDQ_005719

answers: argon–argon

answers: NDQ_005720

answers: argon–argon dating

text: India has been a early leader in the FBR segment and is currently rolling out the next phase of their program. In 2012 an FBR called the Prototype Fast Breeder Reactor was under construction in India, due to be completed that year, with commissioning date known by mid-year.The FBR program of India includes the concept of using fertile thorium-232 to breed fissile uranium-233. India is also pursuing the thorium thermal breeder reactor. A thermal breeder is not possible with purely uranium/plutonium based technology. Thorium fuel is the strategic direction of the power program of India, owing to the nation's large reserves of thorium, but worldwide known reserves of thorium are also some four times those of uranium. India's Department of Atomic Energy (DAE) said in 2007 that it would simultaneously construct four more breeder reactors of 500 MWe each including two at Kalpakkam.

text: India has been a early leader in the FBR segment and is currently rolling out the next phase of their program. In 2012 an FBR called the

text: Prototype Fast Breeder Reactor

text: was under construction in India, due to be completed that year, with commissioning date known by mid-year.The FBR program of India includes the concept of using fertile thorium-232 to breed fissile uranium-233. India is also pursuing the thorium thermal breeder reactor. A thermal breeder is not possible with purely uranium/plutonium based technology. Thorium fuel is the strategic direction of the power program of India, owing to the nation's large reserves of thorium, but worldwide known reserves of thorium are also some four times those of uranium. India's Department of Atomic Energy (DAE) said in 2007 that it would simultaneously construct four more breeder reactors of 500 MWe each including two at Kalpakkam.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: thorium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: thorium-232 to breed fissile

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: thorium-232

answers: NDQ_005712

answers: thorium-232

answers: NDQ_005713

answers: thorium-232

answers: NDQ_005714

answers: uranium-233.

answers: NDQ_005715

answers: thorium-232

answers: NDQ_005716

answers: India has been a early leader in the FBR

answers: NDQ_005717

answers: thorium-232

answers: NDQ_005718

answers: purely uranium/plutonium based technology.

answers: NDQ_005719

answers: thorium-232

answers: NDQ_005720

answers: thorium-232

text: In the 19th century, scientific inquiry had estimated the Age of the Earth in terms of millions of years. By the early 20th Century radiogenic isotopes had been discovered and  Radiometric Dating had been developed. In 1911 Arthur Holmes dated a sample from Ceylon at 1.6 billion years old using lead isotopes.  In 1921 ae yearly meeting of the British Association for the Advancement of Science came to a rough consensus that the Age of the Earth was a few billion years old, and that radiometric dating was credible. Holmes published The Age of the Earth, an Introduction to Geological Ideas in 1927 in which he presented a range of 1.6 to 3.0 billion years. Subsequent dating has taken the Age of the Earth to around 4.55 billion years. Theories that did not comply with the scientific evidence that established the age of the Earth could no longer be accepted.

text: In the 19th century, scientific inquiry had estimated the

text: Age of the Earth

text: in terms of millions of years. By the early 20th Century radiogenic isotopes had been discovered and

text: Radiometric Dating

text: had been developed. In 1911

text: Arthur Holmes

text: dated a sample from Ceylon at 1.6 billion years old using lead isotopes.  In 1921 ae yearly meeting of the

text: British Association for the Advancement of Science

text: came to a rough consensus that the Age of the Earth was a few billion years old, and that radiometric dating was credible. Holmes published The Age of the Earth, an Introduction to Geological Ideas in 1927 in which he presented a range of 1.6 to 3.0 billion years. Subsequent dating has taken the Age of the Earth to around 4.55 billion years. Theories that did not comply with the scientific evidence that established the age of the Earth could no longer be accepted.

answers: NDQ_005711

answers: radiogenic isotopes

answers: NDQ_005712

answers: lead isotopes

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: lead isotopes

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: lead isotopes

answers: NDQ_005717

answers: lead isotopes

answers: NDQ_005718

answers: Theories that did not comply with the scientific evidence

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: using lead isotopes.

answers: NDQ_005712

answers: radiogenic isotopes

answers: NDQ_005713

answers: radiogenic isotopes

answers: NDQ_005714

answers: Radiometric Dating

answers: NDQ_005715

answers: 1.6 billion years old using lead isotopes.

answers: NDQ_005716

answers: lead isotopes.

answers: NDQ_005717

answers: 1.6 billion years old using lead isotopes.

answers: NDQ_005718

answers: Theories that did not comply with the scientific evidence

answers: NDQ_005719

answers: 1.6 billion years old using lead isotopes.

answers: NDQ_005720

answers: 1.6 billion years old using lead isotopes.

text: The Earth's orbital motions (inclination of the earth's axis on its orbit with respect to the sun, gyroscopic precession of the earth's axis every 26,000 years; free precession every 440 days, precession of earth orbit and orbital variations such as perihelion precession every 19,000 and 23,000 years) leave traces visible in the geological record. These changes provide a long-term sequence of climatic events, recorded as changes in the thickness of sediment layers (known as "varve analysis"—the term "varve" means a layer or layers of sediment. Typically, varve refers to lake or glacial sediment), as temperature induced changes in the isotopic ratios for oxygen isotopes in sediments, and in the relative abundance of fossils. Because these can be calibrated reliably over a period of 40 million years this provides an alternate verification to radiometric dating in cases where sufficient record exists to provide a reliable trace.

text: The Earth's orbital motions (inclination of the earth's axis on its orbit with respect to the sun,

text: gyroscopic precession

text: of the earth's axis every 26,000 years;

text: free precession

text: every 440 days,

text: precession of earth orbit

text: and orbital variations such as

text: perihelion precession

text: every 19,000 and 23,000 years) leave traces visible in the geological record. These changes provide a long-term sequence of climatic events, recorded as changes in the thickness of sediment layers (known as "varve analysis"—the term "

text: varve

text: " means a layer or layers of sediment. Typically, varve refers to lake or glacial sediment), as temperature induced changes in the isotopic ratios for oxygen isotopes in sediments, and in the relative abundance of fossils. Because these can be calibrated reliably over a period of 40 million years this provides an alternate verification to

text: radiometric dating

text: in cases where sufficient record exists to provide a reliable trace.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 40 million years

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating in cases where sufficient record exists to provide a reliable trace

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Because these can be calibrated reliably over a period of 40 million years

answers: NDQ_005718

answers: a period of 40 million years

answers: NDQ_005719

answers: radiometric dating in cases where sufficient record exists to provide a reliable trace

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: sufficient record exists to provide a reliable trace.

answers: NDQ_005712

answers: sufficient record exists to provide a reliable trace.

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: these can be calibrated reliably over a period of 40 million years

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: these can be calibrated reliably over a period of 40 million years

answers: NDQ_005718

answers: sufficient record exists to provide a reliable trace.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: A key concept in interpreting radiocarbon dates is archaeological association: what is the true relationship between two or more objects at an archaeological site?  It frequently happens that a sample for radiocarbon dating can be taken directly from the object of interest, but there are also many cases where this is not possible.  Metal grave goods, for example, cannot be radiocarbon dated, but they may be found in a grave with a coffin, charcoal, or other material which can be assumed to have been deposited at the same time.  In these cases a date for the coffin or charcoal is indicative of the date of deposition of the grave goods, because of the direct functional relationship between the two.  There are also cases where there is no functional relationship, but the association is reasonably strong: for example, a layer of charcoal in a rubbish pit provides a date which has a relationship to the rubbish pit.

text: A key concept in interpreting radiocarbon dates is

text: archaeological association

text: : what is the true relationship between two or more objects at an archaeological site?  It frequently happens that a sample for radiocarbon dating can be taken directly from the object of interest, but there are also many cases where this is not possible.  Metal grave goods, for example, cannot be radiocarbon dated, but they may be found in a grave with a coffin, charcoal, or other material which can be assumed to have been deposited at the same time.  In these cases a date for the coffin or charcoal is indicative of the date of deposition of the grave goods, because of the direct functional relationship between the two.  There are also cases where there is no functional relationship, but the association is reasonably strong: for example, a layer of charcoal in a rubbish pit provides a date which has a relationship to the rubbish pit.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon dating can be taken directly from the object of interest, but there are also many cases where this is not possible

answers: NDQ_005714

answers: metal grave goods

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: a sample for radiocarbon dating can be taken directly from the object of interest, but there are also many cases where this is not possible

answers: NDQ_005718

answers: many cases where this is not possible

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: archaeological association:

answers: NDQ_005712

answers: direct functional relationship

answers: NDQ_005713

answers: archaeological association:

answers: NDQ_005714

answers: archaeological association:

answers: NDQ_005715

answers: direct functional relationship

answers: NDQ_005716

answers: direct functional relationship

answers: NDQ_005717

answers: direct functional relationship

answers: NDQ_005718

answers: Metal grave goods, for example, cannot be radiocarbon dated,

answers: NDQ_005719

answers: direct functional relationship

answers: NDQ_005720

answers: direct functional relationship

text: The ages of tektites from the four strewnfields have been determined using radiometric dating methods. The age of moldavites, a type of tektite found in Czech Republic, was determined to be 14 million years, which agrees well with the age determined for the Nördlinger Ries crater (a few hundred kilometers away in Germany) by radiometric dating of Suevite (an impact breccia found at the crater). Similar agreements exist between tektites from the North American strewnfield and the Chesapeake Bay impact crater and between tektites from the Ivory Coast strewnfield and the Lake Bosumtwi-Crater. Ages of tektites have usually been determined by either the K-Ar method, fission-track dating, the Ar-Ar technique, or combination of these techniques.

text: The ages of tektites from the four strewnfields have been determined using

text: radiometric dating

text: methods. The age of

text: moldavite

text: s, a type of tektite found in

text: Czech Republic

text: , was determined to be 14 million years, which agrees well with the age determined for the

text: Nördlinger Ries

text: crater (a few hundred kilometers away in Germany) by radiometric dating of

text: Suevite

text: (an impact

text: breccia

text: found at the crater). Similar agreements exist between tektites from the North American strewnfield and the Chesapeake Bay impact crater and between tektites from the Ivory Coast strewnfield and the Lake Bosumtwi-Crater. Ages of tektites have usually been determined by either the K-Ar method, fission-track dating, the Ar-Ar technique, or combination of these techniques.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: tektites

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: tektites

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: K-Ar method

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiometric dating methods.

answers: NDQ_005712

answers: combination of these techniques.

answers: NDQ_005713

answers: radiometric dating methods.

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: 14 million years,

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: K-Ar method,

answers: NDQ_005718

answers: 14 million years,

answers: NDQ_005719

answers: combination of these techniques.

answers: NDQ_005720

answers: radiometric dating methods.

text: The naturally occurring K, with a half-life of 1.248 years, decays to stable Ar (10.72%) by electron capture and by positron emission, and also transforms to stable Ca (89.28%) via beta decay. These properties and ratios are used to determine the age of rocks through potassium-argon dating.

text: The naturally occurring

text: K

text: , with a

text: half-life

text: of 1.248 years, decays to stable Ar (10.72%) by

text: electron capture

text: and by

text: positron emission

text: , and also transforms to stable Ca (89.28%) via

text: beta decay

text: . These properties and ratios are used to determine the age of

text: rocks

text: through

text: potassium-argon dating

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: positron emission

answers: NDQ_005717

answers: decays to stable Ar

answers: NDQ_005718

answers: half-life

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon dating.

answers: NDQ_005712

answers: potassium-argon dating.

answers: NDQ_005713

answers: potassium-argon dating.

answers: NDQ_005714

answers: potassium-argon dating.

answers: NDQ_005715

answers: 1.248 years, decays to stable Ar

answers: NDQ_005716

answers: beta decay.

answers: NDQ_005717

answers: These properties and ratios are used to determine the age of rocks

answers: NDQ_005718

answers: half-life of 1.248 years,

answers: NDQ_005719

answers: potassium-argon dating.

answers: NDQ_005720

answers: potassium-argon dating.

text: This effect increases when passport numbers are issued sequentially or contain a redundant checksum. Both are proven to be the case in passports issued by the Netherlands . There are other factors that can be potentially used to speed up a brute force attack. There is the fact that dates of birth are typically not distributed randomly in populations. Dates of birth may be distributed even less randomly for the segments of a population that pass, for example, a check-in desk at an airport. And the fact that passports are often not issued on all days of the week and during all weeks of a year. Therefore, not all theoretically possible expiration dates may get used. In addition, the fact that real existing dates are used further limits the number of possible combinations: The month makes up two of the digits used for generating the key. Usually, two digits would mean 100 (00−99) combinations in decimal code or (36×36=1296) combinations in alphanumeric code. But as there are only 12 months, there are only 12 combinations. It is the same with the day (two digits and 31 combinations or less, depending on the month).

text: This effect increases when passport numbers are issued sequentially or contain a redundant

text: checksum

text: . Both are proven to be the case in passports issued by the

text: Netherlands

text: . There are other factors that can be potentially used to speed up a brute force attack. There is the fact that dates of birth are typically not distributed randomly in populations. Dates of birth may be distributed even less randomly for the segments of a population that pass, for example, a check-in desk at an airport. And the fact that passports are often not issued on all days of the week and during all weeks of a year. Therefore, not all theoretically possible expiration dates may get used. In addition, the fact that real existing dates are used further limits the number of possible combinations: The month makes up two of the digits used for generating the key. Usually, two digits would mean 100 (00−99) combinations in decimal code or (36×36=1296) combinations in alphanumeric code. But as there are only 12 months, there are only 12 combinations. It is the same with the day (two digits and 31 combinations or less, depending on the month).

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12 with a half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: are typically not distributed randomly in populations

answers: NDQ_005718

answers: the number of possible combinations

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: real existing dates are used further limits the number of possible combinations:

answers: NDQ_005712

answers: real existing dates are used further limits the number of possible combinations:

answers: NDQ_005713

answers: 12 months, there are only 12 combinations.

answers: NDQ_005714

answers: real existing dates are used further limits the number of possible combinations:

answers: NDQ_005715

answers: 12

answers: NDQ_005716

answers: real existing dates are used further limits the number of possible combinations:

answers: NDQ_005717

answers: 12 months, there are only 12 combinations.

answers: NDQ_005718

answers: real existing dates are used further limits the number of possible combinations:

answers: NDQ_005719

answers: dates of birth are typically not distributed randomly in populations.

answers: NDQ_005720

answers: 12

text: A requester may request to restrict the claims with respect to one or more, but not all, Contracting States. The limitation would then result in claims being different in different Contracting States. This may however only be done in some special cases, one of them being in order to avoid conflict with national prior rights (a national prior right is a national patent filed before the filing date - or priority date - of the European patent subject to the limitation procedure but published after the filing date - or priority date - of the European patent).

text: A requester may request to restrict the claims with respect to one or more, but not all, Contracting States. The limitation would then result in claims being different in different Contracting States. This may however only be done in some special cases, one of them being in order to avoid conflict with national prior rights (a national prior right is a national patent filed before the filing date - or

text: priority date

text: - of the European patent subject to the limitation procedure but published after the filing date - or priority date - of the European patent).

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: isotopes

answers: NDQ_005718

answers: different in different Contracting States

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Contracting States.

answers: NDQ_005712

answers: national prior rights

answers: NDQ_005713

answers: one or more, but not all, Contracting States.

answers: NDQ_005714

answers: in order to avoid conflict with national prior rights

answers: NDQ_005715

answers: A requester may request to restrict the claims

answers: NDQ_005716

answers: filing date - or priority date - of the European patent

answers: NDQ_005717

answers: national prior rights

answers: NDQ_005718

answers: claims being different in different Contracting States.

answers: NDQ_005719

answers: A requester may request to restrict the claims

answers: NDQ_005720

answers: one or more, but not all, Contracting States.

text: Four steps lead down into the interior of the church.  The tower is entered by a very narrow door.  The south arcade is carried on round piers with octagonal abaci, and has pointed arches.  The north arcade is similar, except that one of the piers is octagonal, and has a capital decorated with scallops.  There are fragments of Norman zigzag carving incorporated in the wall above the north transept, and in the west wall of the north aisle.  The reredos dates from 1926, and is by Caröe.  The altar rail dates from the late 17th century, and is carried on balusters.  The pulpit has been reduced from a three-decker and is dated 1721.  The font consists of a small octagonal bowl; its cover is inscribed with the date 1662.  Also in the church is a poor box, cut from a log, and dated 1648.  Only the east window contains stained glass; this dates from 1926 and is by Powells.  In the south transept is a coffin lid from the 13th century, carved with a foliated cross. The two-manual pipe organ was made in 1913 by Binns, and restored in 1951. In the tower are three bells, dated 1687, 1726, and 1764.

text: Four steps lead down into the interior of the church.  The tower is entered by a very narrow door.  The south

text: arcade

text: is carried on round

text: piers

text: with octagonal

text: abaci

text: , and has pointed arches.  The north arcade is similar, except that one of the piers is octagonal, and has a

text: capital

text: decorated with scallops.  There are fragments of Norman zigzag carving incorporated in the wall above the north transept, and in the west wall of the north aisle.  The

text: reredos

text: dates from 1926, and is by Caröe.  The altar rail dates from the late 17th century, and is carried on balusters.  The

text: pulpit

text: has been reduced from a three-decker and is dated 1721.  The

text: font

text: consists of a small octagonal bowl; its cover is inscribed with the date 1662.  Also in the church is a poor box, cut from a log, and dated 1648.  Only the east window contains stained glass; this dates from 1926 and is by

text: Powells

text: .  In the south transept is a coffin lid from the 13th century, carved with a foliated cross. The two-

text: manual

text: pipe organ

text: was made in 1913 by

text: Binns

text: , and restored in 1951. In the tower are three bells, dated 1687, 1726, and 1764.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 1687, 1726, and 1764

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The pulpit has been reduced from a three-decker and is dated 1721.

answers: NDQ_005718

answers: only the east window contains stained glass

answers: NDQ_005719

answers: None of the above choices are available

answers: NDQ_005720

answers: NDQ_005711

answers: 1687, 1726, and 1764.

answers: NDQ_005712

answers: late 17th century,

answers: NDQ_005713

answers: 1687, 1726, and 1764.

answers: NDQ_005714

answers: 1687, 1726, and 1764.

answers: NDQ_005715

answers: 1687, 1726, and 1764.

answers: NDQ_005716

answers: 1687, 1726, and 1764.

answers: NDQ_005717

answers: 1687, 1726, and 1764.

answers: NDQ_005718

answers: 1721.

answers: NDQ_005719

answers: 1687, 1726, and 1764.

answers: NDQ_005720

answers: 1687, 1726, and 1764.

text: The fossil was dated using a combination of palaeomagnetism and uranium-lead (U-Pb) dating which showed that the fossils are not older than ~2.0 Ma. The occurrence of species of animal that became extinct at ~1.5 Ma indicate the deposit is not younger than 1.5 Ma. The sediments have a 'normal' magnetic polarity and the only major period between 2.0 and 1.5 Ma when this occurred is the Olduvai sub-Chron between 1.95 and 1.78 Ma. As such, the fossils were originally dated to ~1.95 Ma. Recent dating of a capping flowstone illustrated this was not possible and the normal magnetic polarity sediments have since been correlated to the 3000-year-long Pre-Olduvai event at ~1.977 Ma.

text: The fossil was dated using a combination of

text: palaeomagnetism

text: and

text: uranium-lead (U-Pb) dating

text: which showed that the fossils are not older than ~2.0 Ma. The occurrence of species of animal that became extinct at ~1.5 Ma indicate the deposit is not younger than 1.5 Ma. The sediments have a 'normal' magnetic polarity and the only major period between 2.0 and 1.5 Ma when this occurred is the Olduvai sub-Chron between 1.95 and 1.78 Ma. As such, the fossils were originally dated to ~1.95 Ma. Recent dating of a capping flowstone illustrated this was not possible and the normal magnetic polarity sediments have since been correlated to the 3000-year-long Pre-Olduvai event at ~1.977 Ma.

answers: NDQ_005711

answers: U-Pb

answers: NDQ_005712

answers: uranium-lead

answers: NDQ_005713

answers: Yes

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: NDQ_005716

answers: U-Pb dating

answers: NDQ_005717

answers: U-Pb

answers: NDQ_005718

answers: uranium-lead

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead (U-Pb)

answers: NDQ_005712

answers: <unk>2.0 Ma.

answers: NDQ_005713

answers: uranium-lead (U-Pb)

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: 2.0 Ma.

answers: NDQ_005716

answers: extinct

answers: NDQ_005717

answers: <unk>2.0 Ma.

answers: NDQ_005718

answers: the fossils are not older than <unk>2.0 Ma.

answers: NDQ_005719

answers: <unk>2.0 Ma.

answers: NDQ_005720

answers: uranium-lead

text: Scientific knowledge of the geologic history of Vesuvius comes from core samples taken from a  plus bore hole on the flanks of the volcano, extending into Mesozoic rock. Cores were dated by potassium–argon and argon–argon dating. The volcano started forming 25,000 years ago. Although the area has been subject to volcanic activity for at least 400,000 years, the lowest layer of eruption material from the Somma caldera lies on top of the 40,000 year‑old Campanian ignimbrite produced by the Campi Flegrei complex, and was the product of the Codola Plinian eruption 25,000 years ago.

text: Scientific knowledge of the geologic history of Vesuvius comes from

text: core sample

text: s taken from a  plus bore hole on the flanks of the volcano, extending into

text: Mesozoic

text: rock. Cores were dated by

text: potassium–argon

text: and

text: argon–argon dating

text: . The volcano started forming 25,000 years ago. Although the area has been subject to volcanic activity for at least 400,000 years, the lowest layer of eruption material from the Somma caldera lies on top of the 40,000 year‑old

text: Campania

text: n

text: ignimbrite

text: produced by the

text: Campi Flegrei

text: complex, and was the product of the Codola

text: Plinian eruption

text: 25,000 years ago.

answers: NDQ_005711

answers: potassium–argon

answers: NDQ_005712

answers: potassium–argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: argon–argon dating

answers: NDQ_005717

answers: core samples taken from a plus bore hole

answers: NDQ_005718

answers: core samples

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium–argon and argon–argon

answers: NDQ_005712

answers: potassium–argon and argon–argon

answers: NDQ_005713

answers: potassium–argon and argon–argon dating.

answers: NDQ_005714

answers: potassium–argon

answers: NDQ_005715

answers: potassium–argon

answers: NDQ_005716

answers: potassium–argon

answers: NDQ_005717

answers: Cores

answers: NDQ_005718

answers: core samples

answers: NDQ_005719

answers: potassium–argon and argon–argon

answers: NDQ_005720

answers: potassium–argon

text: Isotope-ratio analysis for radiometric dating has normally been determined by TIMS. However, some systems (e.g. Hf-W and Lu-Hf) are difficult or impossible to analyse by TIMS, due to the high ionization potential of the elements involved. Therefore, these methods can now be analysed using MC-ICP-MS.

text: Isotope-ratio analysis for

text: radiometric dating

text: has normally been determined by TIMS. However, some systems (e.g. Hf-W and Lu-Hf) are difficult or impossible to analyse by TIMS, due to the high ionization potential of the elements involved. Therefore, these methods can now be analysed using MC-ICP-MS.

answers: NDQ_005711

answers: TIMS

answers: NDQ_005712

answers: TIMS

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: isotope-ratio analysis

answers: NDQ_005715

answers: TIMS

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: TIMS

answers: NDQ_005718

answers: high ionization potential

answers: NDQ_005719

answers: TIMS

answers: NDQ_005720

answers: NDQ_005711

answers: Isotope-ratio analysis

answers: NDQ_005712

answers: high ionization potential

answers: NDQ_005713

answers: MC-ICP-MS.

answers: NDQ_005714

answers: high ionization potential

answers: NDQ_005715

answers: MC-ICP-MS.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: MC-ICP-MS.

answers: NDQ_005718

answers: high ionization potential of the elements involved.

answers: NDQ_005719

answers: MC-ICP-MS.

answers: NDQ_005720

answers: MC-ICP-MS.

text: Radiocarbon dating, done in South Africa, has established that a Leadwood tree can live up to 1070 +/-40 years  and subsequently remain standing for years after the tree has died.

text: Radiocarbon dating

text: , done in South Africa, has established that a Leadwood tree can live up to 1070 +/-40 years  and subsequently remain standing for years after the tree has died.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: can live up to 1070 +/-40 years

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon

answers: NDQ_005715

answers: Leadwood tree can live up to 1070

answers: NDQ_005716

answers: Radiocarbon dating,

answers: NDQ_005717

answers: a Leadwood tree can live up to 1070

answers: NDQ_005718

answers: remain standing for years after the tree has died.

answers: NDQ_005719

answers: Radiocarbon dating,

answers: NDQ_005720

answers: Radiocarbon dating,

text: Uranium-uranium dating is a radiometric dating technique which compares two isotopes of uranium (U) in a sample: uranium-234 (U) and uranium-238 (U). It is one of several radiometric dating techniques exploiting the uranium radioactive decay series, in which U undergoes 14 alpha and beta decay events on the way to the stable isotope Pb. Other dating techniques using this decay series include uranium-thorium dating and uranium-lead dating.

text: Uranium-uranium dating is a

text: radiometric dating

text: technique which compares two

text: isotope

text: s of

text: uranium

text: (U) in a sample:

text: (U) and

text: (U). It is one of several radiometric dating techniques exploiting the

text: uranium radioactive decay series

text: , in which U undergoes 14

text: alpha

text: and

text: beta decay

text: events on the way to the stable isotope

text: Pb

text: . Other dating techniques using this decay series include

text: uranium-thorium dating

text: and

text: uranium-lead dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a stable isotope

answers: NDQ_005715

answers: NDQ_005716

answers: Pb decay

answers: NDQ_005717

answers: isotopes of argon

answers: NDQ_005718

answers: unstable isotope Pb

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: compares two isotopes of uranium

answers: NDQ_005712

answers: uranium radioactive decay series,

answers: NDQ_005713

answers: uranium radioactive decay series,

answers: NDQ_005714

answers: uranium radioactive decay series,

answers: NDQ_005715

answers: uranium radioactive decay series,

answers: NDQ_005716

answers: uranium radioactive decay series,

answers: NDQ_005717

answers: 14 alpha and beta decay events

answers: NDQ_005718

answers: uranium radioactive decay series,

answers: NDQ_005719

answers: uranium-thorium dating

answers: NDQ_005720

answers: uranium-lead dating.

text: In 2016, the development of radiocarbon dating was recognized as a National Historic Chemical Landmark for its contributions to chemistry and society by the American Chemical Society.

text: In 2016, the development of radiocarbon dating was recognized as a

text: National Historic Chemical Landmark

text: for its contributions to chemistry and society by the

text: American Chemical Society

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating was recognized as a National Historic Chemical Landmark

answers: NDQ_005715

answers: radiocarbon dating was recognized as a National Historic Chemical Landmark

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: Paradoxosisyra is known from one adult fossil, the holotype, specimen number "GPIH Typ. Kat. Nr. 4580".  At the time of the genus description, the specimen was residing in the Geological-Paleontological Institute and Museum's C. Gröhn collection, part of the University of Hamburg.  The described specimen is an adult female which has been preserved as an inclusion in a transparent chunk of Burmese amber.  The amber specimens were recovered from deposits in Kachin State, in Myanmar.  Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the Aptian – Cenomanian boundary, in the earliest Cenomanian.

text: Paradoxosisyra is known from one adult fossil, the

text: holotype

text: , specimen number "GPIH Typ. Kat. Nr. 4580".  At the time of the genus description, the specimen was residing in the Geological-Paleontological Institute and Museum's C. Gröhn collection, part of the

text: University of Hamburg

text: .  The described specimen is an adult female which has been preserved as an

text: inclusion

text: in a transparent chunk of

text: Burmese amber

text: .  The

text: amber

text: specimens were recovered from deposits in

text: Kachin State

text: , in Myanmar.  Burmese amber has been

text: radiometrically dated

text: using

text: U

text: Pb

text: isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the

text: Aptian

text: Cenomanian

text: boundary, in the earliest Cenomanian.

answers: NDQ_005711

answers: using U-Pb isotopes

answers: NDQ_005712

answers: U-Pb isotopes

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: U-Pb isotopes

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: Burmese amber

answers: NDQ_005717

answers: radiometrically dated using U-Pb isotopes

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: U-Pb isotopes,

answers: NDQ_005712

answers: U-Pb isotopes,

answers: NDQ_005713

answers: U-Pb isotopes,

answers: NDQ_005714

answers: U-Pb isotopes,

answers: NDQ_005715

answers: U-Pb isotopes,

answers: NDQ_005716

answers: radiometrically dated using U-Pb isotopes,

answers: NDQ_005717

answers: U-Pb isotopes,

answers: NDQ_005718

answers: close to the Aptian – Cenomanian boundary,

answers: NDQ_005719

answers: U-Pb isotopes,

answers: NDQ_005720

answers: U-Pb isotopes,

text: Although the Calendar Round is still in use today, the Maya started using an abbreviated Short Count during the Late Classic period. The Short Count is a count of 13 k'atuns. For this reason, there is no direct correlation between the Long Count and the European calendar. The most generally accepted correlation is the Goodman-Martínez-Thompson, or GMT, correlation. This equates the Long Count date 11.16.0.0.0 13 Ajaw 8 Xul with the Gregorian date of 12 November 1539. Epigraphers Simon Martin and Nikolai Grube argue for a two-day shift from the standard GMT correlation. The Spinden Correlation would shift the Long Count dates back by 260 years; it also accords with the documentary evidence, and is better suited to the archaeology of the Yucatán Peninsula, but presents problems with the rest of the Maya region. The George Vaillant Correlation would shift all Maya dates 260 years later, and would greatly shorten the Postclassic period. Radiocarbon dating of dated wooden lintels at Tikal supports the GMT correlation.

text: Although the

text: Calendar Round

text: is still in use today, the Maya started using an abbreviated

text: Short Count

text: during the Late Classic period. The Short Count is a count of 13 k'atuns. For this reason, there is no direct correlation between the

text: Long Count

text: and the European calendar. The most generally accepted correlation is the Goodman-Martínez-Thompson, or GMT, correlation. This equates the Long Count date 11.16.0.0.0 13 Ajaw 8 Xul with the

text: Gregorian

text: date of 12 November 1539. Epigraphers

text: Simon Martin

text: and

text: Nikolai Grube

text: argue for a two-day shift from the standard GMT correlation. The Spinden Correlation would shift the Long Count dates back by 260 years; it also accords with the documentary evidence, and is better suited to the archaeology of the Yucatán Peninsula, but presents problems with the rest of the Maya region. The George Vaillant Correlation would shift all Maya dates 260 years later, and would greatly shorten the Postclassic period.

text: Radiocarbon dating

text: of dated wooden lintels at Tikal supports the GMT correlation.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon dating

answers: NDQ_005713

answers: Radiocarbon dating

answers: NDQ_005714

answers: radiocarbon dating

answers: NDQ_005715

answers: radiocarbon dating

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon dating of dated wooden lintels at Tikal supports

answers: NDQ_005718

answers: no direct correlation between the Long Count and the European calendar

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: wooden lintels at Tikal supports the GMT correlation.

answers: NDQ_005715

answers: 260

answers: NDQ_005716

answers: dated wooden lintels

answers: NDQ_005717

answers: Radiocarbon dating of dated wooden lintels at Tikal

answers: NDQ_005718

answers: Radiocarbon

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: Radiocarbon dating

text: A 2005 potassium-argon dating of volcanic tuff associated with the Omo remains showed them to date from about 195,000 years ago, making them older than the idaltu fossils and the earliest known remains of anatomically modern humans.

text: A 2005

text: potassium-argon dating

text: of volcanic

text: tuff

text: associated with the

text: Omo remains

text: showed them to date from about 195,000 years ago, making them older than the idaltu fossils and the earliest known remains of

text: anatomically modern humans

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: volcanic tuff associated with the Omo remains

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: anatomically modern humans.

answers: NDQ_005713

answers: potassium-argon

answers: NDQ_005714

answers: anatomically modern humans.

answers: NDQ_005715

answers: 195,000 years ago,

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 195,000 years ago,

answers: NDQ_005718

answers: anatomically modern humans.

answers: NDQ_005719

answers: anatomically modern humans.

answers: NDQ_005720

answers: potassium-argon

text: Kimberella has been found both in the Ediacara Hills of South Australia and in the Ust’ Pinega Formation in the White Sea region of Russia. The White Sea fossils are often associated with the Ediacaran "animals" Tribrachidium and Dickinsonia; meandering trace fossil trails, possibly made by Kimberella; and algae. Beds in the White Sea succession have been dated to  and  by radiometric dating, using uranium-lead ratios in zircons found in volcanic ash layers that are sandwiched between layers that contain Kimberella fossils. Kimberella fossils are also known from beds older and younger than this precisely dated range. The fossils from the Ediacara Hills have not been dated precisely.

text: Kimberella has been found both in the

text: Ediacara Hills

text: of

text: South Australia

text: and in the

text: Ust’ Pinega Formation

text: in the

text: White Sea

text: region of

text: Russia

text: . The White Sea fossils are often associated with the

text: Ediacaran "animals"

text: Tribrachidium

text: and

text: Dickinsonia

text: ; meandering

text: trace fossil

text: trails, possibly made by Kimberella; and

text: algae

text: . Beds in the White Sea succession have been dated to  and  by

text: radiometric dating

text: , using uranium-lead ratios in

text: zircon

text: s found in volcanic ash layers that are sandwiched between layers that contain Kimberella fossils. Kimberella fossils are also known from beds older and younger than this precisely dated range. The fossils from the Ediacara Hills have not been dated precisely.

answers: NDQ_005711

answers: using uranium

answers: NDQ_005712

answers: uranium-lead ratios

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating uses uranium

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: using uranium-lead ratios in zircons

answers: NDQ_005718

answers: precisely dated range

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead ratios

answers: NDQ_005712

answers: uranium-lead ratios

answers: NDQ_005713

answers: uranium-lead ratios

answers: NDQ_005714

answers: radiometric dating, using uranium-lead ratios

answers: NDQ_005715

answers: Ust’ Pinega Formation in the White Sea region of Russia.

answers: NDQ_005716

answers: radiometric dating,

answers: NDQ_005717

answers: uranium-lead ratios

answers: NDQ_005718

answers: precisely dated range.

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: uranium-lead ratios

text: The area of present-day Date was part of ancient Mutsu Province, and was the ancestral home of the Date clan, which rose to prominence from the Kamakura period, and which ruled Sendai Domain during the Edo period. The area of present-day Date was part of the holdings of Sendai Domain. After the Meiji Restoration, the area was organized as part of Nakadōri region of Iwaki Province, and administratively into numerous villages with the establishment of the municipalities system on April 1, 1898. On April 1, 1940, the village of Nagaoka became the town of Date.The modern city of Date was established on January 1, 2006, from the merger of the towns of Hobara, Date (former), Date, Ryōzen, Tsukidate and Yanagawa (all from Date District). The central locality is Hobara.A whole body skeleton of Paleoparadoxia was excavated in Yanagawa on August 21, 1984. The skeleton is named the “Yanagawa Specimen”.Date is about  north-west of Fukushima I Nuclear Power Plant, the site of the nuclear accident that followed the 2011 Tōhoku earthquake and tsunami. Although outside the nuclear accident exclusion zone, the levels of radiation in the city caused residents, and especially schoolchildren, to remain indoors.

text: The area of present-day Date was part of ancient

text: Mutsu Province

text: , and was the ancestral home of the

text: Date clan

text: , which rose to prominence from the

text: Kamakura period

text: , and which ruled

text: Sendai Domain

text: during the

text: Edo period

text: . The area of present-day Date was part of the holdings of Sendai Domain. After the

text: Meiji Restoration

text: , the area was organized as part of

text: Nakadōri

text: region of

text: Iwaki Province

text: , and administratively into numerous villages with the establishment of the municipalities system on April 1, 1898. On April 1, 1940, the village of Nagaoka became the town of Date.The modern city of Date was established on January 1, 2006, from the merger of the towns of

text: Hobara

text: , Date (former), Date,

text: Ryōzen

text: Tsukidate

text: and

text: Yanagawa

text: (all from

text: Date District

text: ). The central locality is

text: Hobara

text: .A whole body skeleton of

text: Paleoparadoxia

text: was excavated in Yanagawa on August 21, 1984. The skeleton is named the “Yanagawa Specimen”.Date is about  north-west of

text: Fukushima I Nuclear Power Plant

text: , the site of the

text: nuclear accident

text: that followed the

text: 2011 Tōhoku earthquake and tsunami

text: . Although outside the nuclear accident exclusion zone, the levels of radiation in the city caused residents, and especially schoolchildren, to remain indoors.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Paleoparadoxia

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: date was established on January 1, 2006

answers: NDQ_005718

answers: levels of radiation

answers: NDQ_005719

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: radiation

answers: NDQ_005712

answers: Paleoparadoxia

answers: NDQ_005713

answers: Fukushima I Nuclear Power Plant,

answers: NDQ_005714

answers: Fukushima I Nuclear Power Plant,

answers: NDQ_005715

answers: Fukushima I Nuclear Power Plant,

answers: NDQ_005716

answers: Hobara.A whole body skeleton

answers: NDQ_005717

answers: “Yanagawa Specimen”.Date

answers: NDQ_005718

answers: residents, and especially schoolchildren, to remain indoors.

answers: NDQ_005719

answers: Fukushima I Nuclear Power Plant,

answers: NDQ_005720

answers: Fukushima I Nuclear Power Plant,

text: In 1960, using the findings of radiometric dating, he published a geological time scale estimating the age of each geological era.

text: In 1960, using the findings of

text: radiometric dating

text: , he published a geological time scale estimating the age of each

text: geological era

answers: NDQ_005711

answers: yes

answers: NDQ_005712

answers: geological time scale

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: isotopes

answers: NDQ_005718

answers: it cannot be used to estimate the age of a geological feature

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiometric dating, he published a geological time scale

answers: NDQ_005712

answers: geological time scale estimating the age of each geological era.

answers: NDQ_005713

answers: radiometric dating,

answers: NDQ_005714

answers: radiometric dating,

answers: NDQ_005715

answers: radiometric dating,

answers: NDQ_005716

answers: radiometric dating,

answers: NDQ_005717

answers: radiometric dating,

answers: NDQ_005718

answers: estimating the age of each geological era.

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: radiometric dating,

text: The southern sea cliffs of Bolshoy Lyakhovsky Island, which were first studied by Baron von Toll, expose a complex sequence of fossiliferous Late and Middle Pleistocene floodplain, eolian, lake, and solifluction sediments cemented by permafrost. In the 1990s and 2000s,a Russian-German multidisciplinary team, which included the Alfred Wegener Institute for Polar and Marine Research and Permafrost Institute, Russian Academy of Sciences, studied the cryolithology, geochronology, ground ice geochemistry, paleobotany, paleontology, sedimentology, and stratigraphy of these sediments. The age of these sediments were studied in great detail using radiocarbon dating of bones, ivory, and plant remains; optically stimulated luminescence dating of bone-bearing sediments; and uranium-thorium dating of associated peat.

text: The southern sea cliffs of Bolshoy Lyakhovsky Island, which were first studied by Baron von Toll, expose a complex sequence of

text: fossil

text: iferous Late and Middle Pleistocene floodplain, eolian, lake, and

text: solifluction

text: sediments cemented by permafrost. In the 1990s and 2000s,a Russian-German multidisciplinary team, which included the

entity_name: Alfred Wegener Institute for Polar and Marine Research

text: Alfred Wegener Institute for Polar and Marine Research

text: and Permafrost Institute, Russian Academy of Sciences, studied the cryolithology,

text: geochronology

text: , ground ice

text: geochemistry

text: paleobotany

text: paleontology

text: sedimentology

text: , and

text: stratigraphy

text: of these sediments. The age of these sediments were studied in great detail using

text: radiocarbon

text: dating of bones, ivory, and plant remains; optically stimulated

text: luminescence dating

text: of bone-bearing sediments; and

text: uranium-thorium dating

text: of associated peat.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon dating of bones

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: uranium-thorium

answers: NDQ_005718

answers: radiocarbon dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating of bones, ivory, and plant remains;

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating of bones, ivory, and plant remains;

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: uranium-thorium dating of associated peat.

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: uranium-thorium dating

text: The South Mountain Batholith was emplaced within in Late Devonian time, about 370 Ma. It intruded into Cambro-Ordovician metasedimentary rocks of the Meguma Supergroup and the overlying Siluro-Devonian metasedimentary to metavolcanic rocks of the Rockville Notch Group.  The South Mountain Batholith and its host rocks are overlain by coarse clastic terrestrial sedimentary rocks of the Horton Group of Late Devonian to early Mississippian age, indicating a minimum exhumation age of about 355 Ma. These stratigraphic constraints are substantiated by radiometric dating that has yielded an age range of 372–361 Ma for the age of the plutons comprising the South Mountain Batholith

text: The South Mountain Batholith was emplaced within in Late

text: Devonian

text: time, about 370 Ma. It intruded into

text: Cambro

text: Ordovician

text: metasedimentary rocks of the Meguma Supergroup and the overlying

text: Siluro

text: -Devonian metasedimentary to metavolcanic rocks of the Rockville Notch Group.  The South Mountain Batholith and its host rocks are overlain by coarse clastic terrestrial sedimentary rocks of the Horton Group of Late Devonian to early Mississippian age, indicating a minimum exhumation age of about 355 Ma. These stratigraphic constraints are substantiated by radiometric dating that has yielded an age range of 372–361 Ma for the age of the plutons comprising the South Mountain Batholith

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: 372–361

answers: NDQ_005713

answers: It is impossible to say

answers: NDQ_005714

answers: radiometric dating is used for dating human remains

answers: NDQ_005715

answers: How long does it take for carbon-14 to decay to carbon-12?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating that has yielded an age range of 372–361 Ma

answers: NDQ_005718

answers: age range of 372–361 Ma

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: stratigraphic constraints

answers: NDQ_005712

answers: 372–361 Ma

answers: NDQ_005713

answers: 372–361 Ma

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: 370 Ma.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 372–361 Ma

answers: NDQ_005718

answers: age range of 372–361 Ma

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Potassium–argon dating, abbreviated K–Ar dating, is a radiometric dating method used in geochronology and archaeology. It is based on measurement of the product of the radioactive decay of an isotope of potassium (K) into argon (Ar). Potassium is a common element found in many materials, such as micas, clay minerals, tephra, and evaporites. In these materials, the decay product Ar is able to escape the liquid (molten) rock, but starts to accumulate when the rock solidifies (recrystallizes). The amount of Argon sublimation that occurs is a function of the purity of the sample, the composition of the mother material, and a number of other factors. These factors introduce error limits on the upper and lower bounds of dating, so that final determination of age is reliant on the environmental factors during formation, melting, and exposure to decreased pressure and/or open-air. Time since recrystallization is calculated by measuring the ratio of the amount of Ar accumulated to the amount of K remaining. The long half-life of K allows the method to be used to calculate the absolute age of samples older than a few thousand years.

text: Potassium–argon dating, abbreviated K–Ar dating, is a

text: radiometric dating

text: method used in

text: geochronology

text: and

text: archaeology

text: . It is based on measurement of the product of the

text: radioactive

text: decay of an

text: isotope

text: of

text: potassium

text: (K) into

text: argon

text: (Ar). Potassium is a common element found in many materials, such as

text: mica

text: s,

text: clay minerals

text: tephra

text: , and

text: evaporites

text: . In these materials, the decay product Ar is able to escape the liquid (molten) rock, but starts to accumulate when the rock solidifies (

text: recrystallizes

text: ). The amount of Argon sublimation that occurs is a function of the purity of the sample, the composition of the mother material, and a number of other factors. These factors introduce error limits on the upper and lower bounds of dating, so that final determination of age is reliant on the environmental factors during formation, melting, and exposure to decreased pressure and/or open-air. Time since recrystallization is calculated by measuring the ratio of the amount of Ar accumulated to the amount of K remaining. The long

text: half-life

text: of K allows the method to be used to calculate the

text: absolute age

text: of samples older than a few thousand years.

answers: NDQ_005711

answers: measurement of the product of the radioactive decay

answers: NDQ_005712

answers: a few thousand years

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: argon

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: time since recrystallization is calculated by measuring the ratio of the amount of Ar accumulated to the amount of K remaining

answers: NDQ_005718

answers: error limits on the upper and lower bounds of dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: measurement of the product of the radioactive decay

answers: NDQ_005712

answers: older than a few thousand years.

answers: NDQ_005713

answers: potassium (K) into argon (Ar).

answers: NDQ_005714

answers: a few thousand years.

answers: NDQ_005715

answers: K

answers: NDQ_005716

answers: (recrystallizes).

answers: NDQ_005717

answers: measurement of the product of the radioactive decay

answers: NDQ_005718

answers: error limits on the upper and lower bounds of dating,

answers: NDQ_005719

answers: a few thousand years.

answers: NDQ_005720

answers: Potassium–argon dating,

text: When several radiocarbon dates are obtained for samples which are known or suspected to be from the same object, it may be possible to combine the measurements to get a more accurate date. Unless the samples are definitely of the same age (for example, if they were both physically taken from a single item) a statistical test must be applied to determine if the dates do derive from the same object. This is done by calculating a combined error term for the radiocarbon dates for the samples in question, and then calculating a pooled mean age. It is then possible to apply a T test to determine if the samples have the same true mean. Once this is done the error for the pooled mean age can be calculated, giving a final answer of a single date and range, with a narrower probability distribution (i.e., greater accuracy) as a result of the combined measurements.

text: When several radiocarbon dates are obtained for samples which are known or suspected to be from the same object, it may be possible to combine the measurements to get a more accurate date. Unless the samples are definitely of the same age (for example, if they were both physically taken from a single item) a statistical test must be applied to determine if the dates do derive from the same object. This is done by calculating a combined error term for the radiocarbon dates for the samples in question, and then calculating a pooled mean age. It is then possible to apply a

text: T test

text: to determine if the samples have the same true mean. Once this is done the error for the pooled mean age can be calculated, giving a final answer of a single date and range, with a narrower probability distribution (i.e., greater accuracy) as a result of the combined measurements.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: samples are definitely of the same age

answers: NDQ_005713

answers: NDQ_005714

answers: human remains and artifacts are very old

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: combine the measurements to get a more accurate date

answers: NDQ_005718

answers: Unless the samples are definitely of the same age

answers: NDQ_005719

answers: NDQ_005720

answers: context: radiocarbon

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: same age

answers: NDQ_005713

answers: When several radiocarbon dates

answers: NDQ_005714

answers: greater accuracy)

answers: NDQ_005715

answers: When several radiocarbon

answers: NDQ_005716

answers: date.

answers: NDQ_005717

answers: it may be possible to combine the measurements to get a more accurate date.

answers: NDQ_005718

answers: Unless the samples are definitely of the same age

answers: NDQ_005719

answers: When several radiocarbon dates

answers: NDQ_005720

answers: radiocarbon dates

text: The radiocarbon test gave a possible date of construction during Agricola campaign.

text: The radiocarbon test gave a possible date of construction during

text: Agricola

text: campaign.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon is an element

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: The radiocarbon test gave a possible date of construction

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: The radiocarbon

answers: NDQ_005714

answers: The radiocarbon

answers: NDQ_005715

answers: The radiocarbon

answers: NDQ_005716

answers: The radiocarbon

answers: NDQ_005717

answers: radiocarbon test gave a possible date of construction during Agricola campaign.

answers: NDQ_005718

answers: The radiocarbon

answers: NDQ_005719

answers: The radiocarbon

answers: NDQ_005720

answers: The radiocarbon test

text: Dating Method Two: Radiocarbon Dating

text: Dating Method Two: Radiocarbon Dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: carbon is a non-reactive element

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12 with a half-life of 5,730

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: Radiocarbon dating is a method of determining the age of a sample by measuring the amount of argon in the sample.

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: Radiocarbon dating is useful for very young materials

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: Radiocarbon Dating

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon Dating

answers: NDQ_005714

answers: Radiocarbon Dating

answers: NDQ_005715

answers: Radiocarbon Dating

answers: NDQ_005716

answers: Radiocarbon Dating

answers: NDQ_005717

answers: Radiocarbon Dating

answers: NDQ_005718

answers: Radiocarbon

answers: NDQ_005719

answers: Radiocarbon Dating

answers: NDQ_005720

answers: Radiocarbon Dating

text: Until more perspective is added here on the importance of these tools to extraterrestrial materials research, you can find clues to some strategies not mentioned here under radiometric dating.

text: Until more perspective is added here on the importance of these tools to extraterrestrial materials research, you can find clues to some strategies not mentioned here under

text: radiometric dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: extraterrestrial

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: radiometric dating.

answers: NDQ_005712

answers: extraterrestrial materials

answers: NDQ_005713

answers: radiometric dating.

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: radiometric dating.

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: radiometric dating.

answers: NDQ_005718

answers: strategies not mentioned here

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: The cone is formed by reddish scoria. Its rocks are basaltic andesite. It was erupted 3.1 ± 0.2 million years ago on the basis of potassium-argon dating. Other dates are 3.05 ± 0.22, 3.35 ± 0.16 and 2.34 ± 0.16 mya. Which age is correct is unclear, but the cone is partly buried by the 2.72 mya old Lauca-Pérez ignimbrite indicating that it's older than this ignimbrite.

text: The cone is formed by reddish

text: scoria

text: . Its rocks are

text: basaltic andesite

text: . It was erupted 3.1 ± 0.2 million years ago on the basis of

text: potassium-argon dating

text: . Other dates are 3.05 ± 0.22, 3.35 ± 0.16 and 2.34 ± 0.16 mya. Which age is correct is unclear, but the cone is partly buried by the 2.72 mya old Lauca-Pérez

text: ignimbrite

text: indicating that it's older than this ignimbrite.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: It was erupted 3.1  0.22 million years ago

answers: NDQ_005718

answers: which age is correct is unclear

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: potassium-argon dating.

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: 2.72 mya old Lauca-Pérez

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: It was erupted 3.1 <unk> 0.2 million years ago

answers: NDQ_005718

answers: Which age is correct is unclear,

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: potassium-argon

text: Geologists have attempted to date the Cardenas Basalt for many years. On the basis of other geologic criteria, geologists have found that the dates, which range from 1,000 to 700 million years ago, obtained for the age of the Cardenas Basalt and upper age of the Unkar Group, were too young, and something was clearly perturbing the dating systematics. The current interpretation is that the deposition of the overlying Chuar Group, in a marine setting, disrupted the potassium-argon (K-Ar) radiometric system. Apparently, fluids associated with the deposition of the Chuar Group have altered the older Cardenas Basalt, partially degraded the minerals, and therefore producing a disruption in the K-Ar systematics. Using newer dating techniques and approaches not available to earlier geologists, the Cardenas Basalt and intrusive sills have been re-dated. New data acquired using newer dating techniques and approaches, indicate that the Cardenas Basalt erupted about 1,104 million years ago. This date marks the end of the deposition of the Unkar Group. These radiometric dates are corroborated by the radiometric dating of detrial micas and zircons from the Hakatai Shale, Shinumo Quartzite, and Dox Formation. Based on all of these radiometric dates, researchers have concluded that the Unkar Group was deposited between about 1254 and 1100 Ma, with a hiatus of unknown duration between the Hakatai Shale and Shinumo Quartzite.

text: Geologist

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: K-Ar radiometric system

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon (K-Ar) radiometric system

answers: NDQ_005715

answers: K-Ar

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: (K-Ar) radiometric system

answers: NDQ_005718

answers: too young

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon (K-Ar) radiometric system.

answers: NDQ_005712

answers: 1,000 to 700 million years ago,

answers: NDQ_005713

answers: (K-Ar) radiometric system.

answers: NDQ_005714

answers: (K-Ar) radiometric system.

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: radiometric dating of detrial micas and zircons

answers: NDQ_005717

answers: the deposition of the overlying Chuar Group,

answers: NDQ_005718

answers: too young,

answers: NDQ_005719

answers: potassium-argon (K-Ar) radiometric system.

answers: NDQ_005720

answers: radiometric dating

text: In 2004 a new radiocarbon calibration curve, INTCAL04, was internationally ratified to provide calibrated dates back to 26,000 B.P. For the period back to 12,400 B.P., the radiocarbon dates are calibrated against dendrochronological dates.

text: In 2004 a new

text: radiocarbon calibration curve

text: , INTCAL04, was internationally ratified to provide calibrated dates back to 26,000

text: B.P.

text: For the period back to 12,400 B.P., the radiocarbon dates are calibrated against dendrochronological dates.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: dendrochronological

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: dendrochronological

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: calibrated against dendrochronological dates

answers: NDQ_005718

answers: calibrated against dendrochronological dates

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: 26,000 B.P.

answers: NDQ_005713

answers: the radiocarbon dates are calibrated against dendrochronological dates.

answers: NDQ_005714

answers: the radiocarbon dates are calibrated against dendrochronological dates.

answers: NDQ_005715

answers: 26,000 B.P.

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: the radiocarbon dates are calibrated against dendrochronological dates.

answers: NDQ_005718

answers: dendrochronological dates.

answers: NDQ_005719

answers: dendrochronological dates.

answers: NDQ_005720

answers: 26,000 B.P.

text: In 1948, following the establishment of a nuclear sciences team at the DSIR, Rafter was sent to the United States to train in radiochemistry and to visit nuclear establishments in the United States, Canada and England. On Rafter's return, he began to work with the new technique of radiocarbon dating, which dates organic material by comparing the ratio of radiocarbon atoms (carbon-14) to regular carbon atoms (carbon-12) with established radiocarbon: carbon ratios from the past. Rafter first used the method to date moa bones and ash showers from volcanos on the North Island of New Zealand. After difficulties with the process published by Willard Libby, radiocarbon dating’s American pioneer, Rafter worked with DSIR physicist Gordon Fergusson and their team to perfect a new and reliable method of radiocarbon dating using carbon dioxide gas rather than solid carbon.

text: In 1948, following the establishment of a nuclear sciences team at the DSIR, Rafter was sent to the United States to train in

text: radiochemistry

text: and to visit nuclear establishments in the United States,

text: Canada

text: and

text: England

text: . On Rafter's return, he began to work with the new technique of radiocarbon dating, which dates organic material by comparing the ratio of radiocarbon atoms (

text: ) to regular

text: carbon atom

text: s (

text: ) with established radiocarbon: carbon ratios from the past. Rafter first used the method to date

text: moa

text: bones and ash showers from volcanos on the

text: North Island of New Zealand

text: . After difficulties with the process published by Willard Libby, radiocarbon dating’s American pioneer, Rafter worked with DSIR physicist Gordon Fergusson and their team to perfect a new and reliable method of radiocarbon dating using

text: carbon dioxide

text: gas rather than solid carbon.

answers: NDQ_005711

answers: comparing the ratio

answers: NDQ_005712

answers: carbon dioxide gas

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon dioxide gas rather than solid carbon

answers: NDQ_005715

answers: what is the half-life of carbon-14

answers: NDQ_005716

answers: radiocarbon atoms

answers: NDQ_005717

answers: carbon dioxide gas rather than solid carbon

answers: NDQ_005718

answers: carbon dioxide gas

answers: NDQ_005719

answers: Which of the following is not useful for very young materials: potassium-argon or uranium-lead dating?

answers: NDQ_005720

answers: NDQ_005711

answers: comparing the ratio of radiocarbon atoms

answers: NDQ_005712

answers: established radiocarbon: carbon ratios from the past.

answers: NDQ_005713

answers: radiocarbon dating,

answers: NDQ_005714

answers: established radiocarbon: carbon ratios from the past.

answers: NDQ_005715

answers: carbon dioxide gas

answers: NDQ_005716

answers: carbon dioxide gas rather than solid carbon.

answers: NDQ_005717

answers: carbon dioxide gas rather than solid carbon.

answers: NDQ_005718

answers: solid carbon.

answers: NDQ_005719

answers: radiocarbon dating,

answers: NDQ_005720

answers: radiocarbon dating,

text: Pacific models propose that people first reached the Americas via water travel, following coastlines from northeast Asia into the Americas. Coastlines are unusually productive environments because they provide humans with access to a diverse array of plants and animals from both terrestrial and marine ecosystems. While not exclusive of land-based migrations, the Pacific 'coastal migration theory' helps explain how early colonists reached areas extremely distant from the Bering Strait region, including sites such as Monte Verde in southern Chile and Taima-Taima in western Venezuela. Two cultural components were discovered at Monte Verde near the Pacific coast of Chile. The youngest layer is radiocarbon dated at 12,500 radiocarbon years (~14,000 cal BP)  and has produced the remains of several types of seaweeds collected from coastal habitats. The older and more controversial component may date back as far as 33,000 years, but few scholars currently accept this very early component.

text: Pacific models propose that people first reached the Americas via water travel, following coastlines from northeast Asia into the Americas. Coastlines are unusually productive environments because they provide humans with access to a diverse array of plants and animals from both terrestrial and marine ecosystems. While not exclusive of land-based migrations, the Pacific 'coastal migration theory' helps explain how early colonists reached areas extremely distant from the Bering Strait region, including sites such as

text: Monte Verde

text: in southern Chile and

text: Taima-Taima

text: in western

text: Venezuela

text: . Two cultural components were discovered at Monte Verde near the Pacific coast of Chile. The youngest layer is

text: radiocarbon dated

text: at 12,500 radiocarbon years (~14,000 cal BP)  and has produced the remains of several types of seaweeds collected from coastal habitats. The older and more controversial component may date back as far as 33,000 years, but few scholars currently accept this very early component.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: 14,000 cal BP

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: cal BP

answers: NDQ_005717

answers: radiocarbon dated at 12,500 radiocarbon years

answers: NDQ_005718

answers: few scholars currently accept this very early component.

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: 12,500 radiocarbon years

answers: NDQ_005713

answers: 12,500 radiocarbon years (<unk>14,000 cal BP)

answers: NDQ_005714

answers: 12,500 radiocarbon years

answers: NDQ_005715

answers: 12,500 radiocarbon years

answers: NDQ_005716

answers: remains

answers: NDQ_005717

answers: 12,500 radiocarbon years

answers: NDQ_005718

answers: few scholars currently accept this very early component.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: 12,500 radiocarbon years

text: In the chamber’s northern sector there used to be a stone bed. Based only on the architectural features of the premise, and due to the lack of precise dating archeological material it is difficult to make the precise dating. The tomb dates back to the 4th century BC.

text: In the chamber’s northern sector there used to be a stone bed. Based only on the architectural features of the premise, and due to the lack of precise dating archeological material it is difficult to make the precise dating. The tomb dates back to the 4th century BC.

answers: NDQ_005711

answers: no

answers: NDQ_005712

answers: radiometric dating is not accurate

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 4th century BC

answers: NDQ_005718

answers: lack of precise dating archeological material

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: precise dating archeological material

answers: NDQ_005712

answers: lack of precise dating archeological material

answers: NDQ_005713

answers: 4th century BC.

answers: NDQ_005714

answers: due to the lack of precise dating archeological material

answers: NDQ_005715

answers: 4th century BC.

answers: NDQ_005716

answers: precise dating archeological material it is difficult to make the precise dating.

answers: NDQ_005717

answers: 4th century BC.

answers: NDQ_005718

answers: lack of precise dating archeological material

answers: NDQ_005719

answers: 4th century BC.

answers: NDQ_005720

answers: 4th century BC.

text: Uday Prakash came up with a unique idea of finding his lead actor by creating an online poll. It resulted in actor Ajay Rao being the unanimous choice and he was signed on for the same. However, the project got much delayed in taking off and the actor refused the role due to date issues. This resulted in further delay as Prakash went in search of many other younger heroes with nobody willing to accept the role. Later, actor Ganesh was approached and it took at least 20 days to convince him to sign in for the role. Malayalam actress Bhama was roped in soon for the lead heroine. For the other heroine, director approached Chaitra Chandranath, a budding actress, who reportedly walked out due to clash of dates and contract signed for another production. Another young actress, Deepika Kamaiah replaced Chaitra and confirmed her dates for the second lead role.

text: Uday Prakash came up with a unique idea of finding his lead actor by creating an online poll. It resulted in actor

text: Ajay Rao

text: being the unanimous choice and he was signed on for the same. However, the project got much delayed in taking off and the actor refused the role due to date issues. This resulted in further delay as Prakash went in search of many other younger heroes with nobody willing to accept the role. Later, actor

text: Ganesh

text: was approached and it took at least 20 days to convince him to sign in for the role. Malayalam actress

text: Bhama

text: was roped in soon for the lead heroine. For the other heroine, director approached Chaitra Chandranath, a budding actress, who reportedly walked out due to clash of dates and contract signed for another production. Another young actress, Deepika Kamaiah replaced Chaitra and confirmed her dates for the second lead role.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Ganesh was approached

answers: NDQ_005718

answers: date issues

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: online poll.

answers: NDQ_005712

answers: younger

answers: NDQ_005713

answers: Ajay Rao

answers: NDQ_005714

answers: online poll.

answers: NDQ_005715

answers: Deepika Kamaiah

answers: NDQ_005716

answers: online poll. It resulted in actor Ajay Rao

answers: NDQ_005717

answers: Ajay Rao

answers: NDQ_005718

answers: date issues.

answers: NDQ_005719

answers: Chaitra Chandranath, a budding actress,

answers: NDQ_005720

answers: Ajay Rao

text: Argon-39, with a half-life of 269 years, has been used for a number of applications, primarily ice core and ground water dating. Also, potassium-argon dating is used to date igneous rocks.

text: Argon-39, with a half-life of 269 years, has been used for a number of applications, primarily

text: ice core

text: and

text: ground water

text: dating. Also,

text: potassium-argon dating

text: is used to date

text: igneous rock

text: s.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Argon-39

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: argon-39 has a half-life of 269 years

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: Argon-39

answers: NDQ_005717

answers: used to date igneous rocks

answers: NDQ_005718

answers: half-life

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: ice core

answers: NDQ_005712

answers: 269 years,

answers: NDQ_005713

answers: Argon-39,

answers: NDQ_005714

answers: a half-life of 269 years,

answers: NDQ_005715

answers: Argon-39,

answers: NDQ_005716

answers: date igneous rocks.

answers: NDQ_005717

answers: used to date igneous rocks.

answers: NDQ_005718

answers: half-life of 269 years,

answers: NDQ_005719

answers: igneous rocks.

answers: NDQ_005720

answers: Argon-39,

text: Radiocarbon is a scientific journal devoted to the topic of radiocarbon dating. It was founded in 1959 as a supplement to the American Journal of Science, and is an important source of data and information about radiocarbon dating.  It publishes many radiocarbon results, and since 1979 it has published the proceedings of the international conferences on radiocarbon dating.

text: Radiocarbon is a scientific journal devoted to the topic of

text: radiocarbon dating

text: . It was founded in 1959 as a supplement to the

text: American Journal of Science

text: , and is an important source of data and information about radiocarbon dating.  It publishes many radiocarbon results, and since 1979 it has published the proceedings of the international conferences on radiocarbon dating.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon dating.

answers: NDQ_005714

answers: radiocarbon dating.

answers: NDQ_005715

answers: Radiocarbon

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: radiocarbon dating.

text: Lexone is a volcano, now eroded, southeast of Tacora in Chile. Some lava domes were dated by potassium-argon dating to be 60,000 to 70,000 years old and were formerly considered to be of Holocene age.

text: Lexone is a

text: volcano

text: , now eroded, southeast of

text: Tacora

text: in

text: Chile

text: . Some

text: lava dome

text: s were dated by

text: potassium-argon dating

text: to be 60,000 to 70,000 years old and were formerly considered to be of

text: Holocene

text: age.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: lava domes were dated to be 60,000 to 70,000 years old

answers: NDQ_005718

answers: potassium-argon dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 60,000 to 70,000 years old

answers: NDQ_005713

answers: potassium-argon dating to be 60,000 to 70,000 years old

answers: NDQ_005714

answers: Holocene age.

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 60,000 to 70,000 years old

answers: NDQ_005718

answers: Holocene age.

answers: NDQ_005719

answers: 60,000 to 70,000 years old

answers: NDQ_005720

answers: 60,000 to 70,000 years old

text: Potassium-argon dating by Yoshitomo Nishimitsu of Kyoto University indicates that Molokini erupted approximately 230,000 years ago.

text: Potassium-argon dating

text: by Yoshitomo Nishimitsu of

text: Kyoto University

text: indicates that Molokini erupted approximately 230,000 years ago.

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: argon is a noble gas

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: Yoshitomo Nishimitsu

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: Potassium-argon

answers: NDQ_005713

answers: Potassium-argon

answers: NDQ_005714

answers: Potassium-argon

answers: NDQ_005715

answers: Potassium-argon

answers: NDQ_005716

answers: Potassium-argon

answers: NDQ_005717

answers: Molokini erupted approximately 230,000 years ago.

answers: NDQ_005718

answers: 230,000 years ago.

answers: NDQ_005719

answers: Potassium-argon

answers: NDQ_005720

answers: Potassium-argon

text: Rubidium-87 has a half-life of  years, which is more than three times the age of the universe of  years, making it a primordial nuclide. It readily substitutes for potassium in minerals, and is therefore fairly widespread. Rb has been used extensively in dating rocks; Rb beta decays to stable Sr. During fractional crystallization, Sr tends to concentrate in plagioclase, leaving Rb in the liquid phase. Hence, the Rb/Sr ratio in residual magma may increase over time, and the progressing differentiation results in rocks with elevated Rb/Sr ratios. The highest ratios (10 or more) occur in pegmatites. If the initial amount of Sr is known or can be extrapolated, then the age can be determined by measurement of the Rb and Sr concentrations and of the Sr/Sr ratio. The dates indicate the true age of the minerals only if the rocks have not been subsequently altered (see rubidium-strontium dating).

text: Rubidium-87 has a

text: half-life

text: of  years, which is more than three times the

text: age of the universe

text: of  years, making it a

text: primordial nuclide

text: . It readily substitutes for

text: potassium

text: in

text: mineral

text: s, and is therefore fairly widespread. Rb has been used extensively in

text: dating rocks

text: ; Rb

text: beta decay

text: s to stable Sr. During

text: fractional crystallization

text: , Sr tends to concentrate in

text: plagioclase

text: , leaving Rb in the liquid phase. Hence, the Rb/Sr ratio in residual

text: magma

text: may increase over time, and the progressing

text: differentiation

text: results in rocks with elevated Rb/Sr ratios. The highest ratios (10 or more) occur in

text: pegmatite

text: s. If the initial amount of Sr is known or can be extrapolated, then the age can be determined by measurement of the Rb and Sr concentrations and of the Sr/Sr ratio. The dates indicate the true age of the minerals only if the rocks have not been subsequently altered (see

text: rubidium-strontium dating

answers: NDQ_005711

answers: measurement of the Rb and Sr concentrations

answers: NDQ_005712

answers: minerals have not been subsequently altered

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: rubidium-strontium dating

answers: NDQ_005715

answers: NDQ_005716

answers: rubidium-strontium dating

answers: NDQ_005717

answers: It readily substitutes for potassium in minerals, and is therefore fairly widespread

answers: NDQ_005718

answers: The dates indicate the true age of the minerals only if the rocks have not been altered

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: measurement of the Rb and Sr concentrations

answers: NDQ_005712

answers: if the rocks have not been subsequently altered

answers: NDQ_005713

answers: rubidium-strontium dating).

answers: NDQ_005714

answers: rubidium-strontium dating).

answers: NDQ_005715

answers: Rubidium-87

answers: NDQ_005716

answers: if the rocks have not been subsequently altered

answers: NDQ_005717

answers: rubidium-strontium dating).

answers: NDQ_005718

answers: if the rocks have not been subsequently altered

answers: NDQ_005719

answers: rubidium-strontium dating).

answers: NDQ_005720

answers: rubidium-strontium dating).

text: Anthropologist Colin Groves states that 19th-century finds were generally "found by accident and by amateurs", and were thus generally lacking proper documentation of crucial contextual information, and that the dates assigned were therefore suspect. Cremo and Thompson fail to take account of this, he says, and seem to want to accord equal value to all finds. Groves also states that their discussion of radiometric dating fails to take account of the ongoing refinement of these methods, and the resulting fact that later results are more reliable than earlier ones. He concludes that the book is only "superficially scholarly".

text: Anthropologist

text: Colin Groves

text: states that 19th-century finds were generally "found by accident and by amateurs", and were thus generally lacking proper documentation of crucial contextual information, and that the dates assigned were therefore suspect. Cremo and Thompson fail to take account of this, he says, and seem to want to accord equal value to all finds. Groves also states that their discussion of

text: radiometric dating

text: fails to take account of the ongoing refinement of these methods, and the resulting fact that later results are more reliable than earlier ones. He concludes that the book is only "superficially scholarly".

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: later results are more reliable

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: later results are more reliable than earlier ones

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: later results are more reliable than earlier ones

answers: NDQ_005718

answers: later results are more reliable than earlier ones

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: later results are more reliable than earlier ones.

answers: NDQ_005712

answers: later results are more reliable than earlier ones.

answers: NDQ_005713

answers: later results are more reliable than earlier ones.

answers: NDQ_005714

answers: later results are more reliable than earlier ones.

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: later results are more reliable than earlier ones.

answers: NDQ_005718

answers: later results are more reliable than earlier ones.

answers: NDQ_005719

answers: later results are more reliable than earlier ones.

answers: NDQ_005720

answers: radiometric dating

text: The lunar geological timescale (or selenological timescale) divides the history of Earth's Moon into five generally recognized periods: the Copernican, Eratosthenian, Imbrian (Late and Early epochs), Nectarian, and Pre-Nectarian. The boundaries of this time scale are related to large impact events that have modified the lunar surface, changes in crater form that occur through time, and the size-frequency distribution of craters superposed on geological units. The absolute ages for these periods have been constrained by radiometric dating of samples obtained from the lunar surface. However, there is still much debate concerning the ages of certain key events, because correlating lunar regolith samples with geological units on the Moon is difficult, and most lunar radiometric ages have been highly affected by an intense history of bombardment.

text: The lunar geological timescale (or selenological timescale) divides the history of

text: Earth

text: 's

text: Moon

text: into five generally recognized periods: the

text: Copernican

text: Eratosthenian

text: , Imbrian (

text: Late

text: and

text: Early

text: epochs),

text: Nectarian

text: , and

text: Pre-Nectarian

text: . The boundaries of this time scale are related to large

text: impact event

text: s that have modified the

text: lunar surface

text: , changes in

text: crater

text: form that occur through time, and the size-frequency distribution of craters superposed on geological units. The absolute ages for these periods have been constrained by

text: radiometric dating

text: of samples obtained from the lunar surface. However, there is still much debate concerning the ages of certain key events, because correlating lunar

text: regolith

text: samples with geological units on the Moon is difficult, and most lunar radiometric ages have been highly affected by an intense history of bombardment.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: radiometric dating of samples obtained from the lunar surface

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating of samples obtained from the lunar surface

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: absolute ages for these periods have been constrained

answers: NDQ_005718

answers: highly affected by an intense history of bombardment

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: samples obtained from the lunar surface.

answers: NDQ_005712

answers: samples obtained from the lunar surface.

answers: NDQ_005713

answers: radiometric dating of samples obtained from the lunar surface.

answers: NDQ_005714

answers: radiometric dating of samples obtained from the lunar surface.

answers: NDQ_005715

answers: Nectarian, and Pre-Nectarian.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating of samples obtained from the lunar surface.

answers: NDQ_005718

answers: correlating lunar regolith samples with geological units on the Moon

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: The theory holds that ALH84001 was blasted off from the surface of Mars by a meteorite impact about 17 million years ago and fell on Earth roughly 13,000 years ago. These dates were established by a variety of radiometric dating techniques, including samarium-neodymium (Sm-Nd), rubidium-strontium (Rb-Sr), potassium-argon (K-Ar), and carbon-14. Other meteorites that have potential biological markings have generated less interest because they do not contain rock from a "wet" Mars. ALH84001 is the only meteorite collected from such a time period.

text: The theory holds that ALH84001 was blasted off from the surface of Mars by a meteorite impact about 17 million years ago and fell on

text: Earth

text: roughly 13,000 years ago. These dates were established by a variety of

text: radiometric dating

text: techniques, including

text: samarium-neodymium

text: (Sm-Nd),

text: rubidium-strontium

text: (Rb-Sr),

text: potassium-argon

text: (K-Ar), and

text: . Other meteorites that have potential biological markings have generated less interest because they do not contain rock from a "wet" Mars. ALH84001 is the only meteorite collected from such a time period.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: ALH84001 is the only meteorite collected from such a time period

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating techniques

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: K-Ar

answers: NDQ_005718

answers: they do not contain rock from a "wet" Mars

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: a variety of radiometric dating techniques,

answers: NDQ_005712

answers: they do not contain rock from a "wet" Mars.

answers: NDQ_005713

answers: carbon-14.

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: carbon-14.

answers: NDQ_005716

answers: carbon-14.

answers: NDQ_005717

answers: (K-Ar),

answers: NDQ_005718

answers: they do not contain rock from a "wet" Mars.

answers: NDQ_005719

answers: carbon-14.

answers: NDQ_005720

answers: carbon-14.

text: Combinations of the use of the above equations, such as U-Th-Pb dating, U-Pb dating and Pb-Pb dating, require different levels of analysis techniques and offer variable levels of precision and accuracy. The general uncertainty in the ages measured is 2σ (e.g.).

text: Combinations of the use of the above equations, such as U-Th-Pb dating,

text: U-Pb dating

text: and Pb-Pb dating, require different levels of analysis techniques and offer variable levels of precision and accuracy. The general uncertainty in the ages measured is 2σ (e.g.).

answers: NDQ_005711

answers: U-Th-Pb

answers: NDQ_005712

answers: Pb-Pb

answers: NDQ_005713

answers: NDQ_005714

answers: U-Th-Pb

answers: NDQ_005715

answers: U-Th

answers: NDQ_005716

answers: Pb decay

answers: NDQ_005717

answers: Pb-Pb dating

answers: NDQ_005718

answers: uncertainty in the ages measured

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: equations,

answers: NDQ_005712

answers: The general uncertainty in the ages measured is 2<unk>

answers: NDQ_005713

answers: The general uncertainty in the ages measured is 2<unk>

answers: NDQ_005714

answers: offer variable levels of precision and accuracy.

answers: NDQ_005715

answers: U-Th-Pb dating,

answers: NDQ_005716

answers: ages

answers: NDQ_005717

answers: The general uncertainty in the ages measured is 2<unk>

answers: NDQ_005718

answers: The general uncertainty in the ages measured is 2<unk>

answers: NDQ_005719

answers: U-Th-Pb dating,

answers: NDQ_005720

answers: U-Th-Pb dating,

text: The Member 4 deposits containing the Australopithecus africanus fossils have been dated to between 2.6 and 2.0 Ma, with the Sts5 'Mrs Ples' fossil estimated to date to between 2.05-2.01 Ma based on a combination of uranium-lead dating and palaeomagnetic analysis and electron spin resonance dating  The StW 573 partial skeleton (Little Foot) was recovered from a separate infill at the site within the confines of the Silberberg Grotto. It is estimated to be around 2.6-2.2 Ma based on a combination of uranium-lead dating and palaeomagnetic analysis and belongs to a second species of australopith, Australopithecus prometheus. In contrast, surface exposure dating of sediments indicate that skeleton StW 573 has an age of approximately 4 million years. While the flowstone dated in the uranium-lead dating has been shown to have formed later than the fossil, an age estimate of ~3 Ma suggested by the same authors  has little firm basis. The palaeomagnetic analysis  remains the most credible age estimate based on the current data as it included work on both sediments and speleothem.

text: The Member 4 deposits containing the

text: Australopithecus africanus

text: fossils have been dated to between 2.6 and 2.0 Ma, with the Sts5 'Mrs Ples' fossil estimated to date to between 2.05-2.01 Ma based on a combination of

text: uranium-lead dating

text: and

text: palaeomagnetic

text: analysis and

text: electron spin resonance

text: dating  The StW 573 partial skeleton (

text: Little Foot

text: ) was recovered from a separate infill at the site within the confines of the Silberberg Grotto. It is estimated to be around 2.6-2.2 Ma based on a combination of uranium-lead dating and palaeomagnetic analysis and belongs to a second species of australopith,

text: Australopithecus prometheus

text: . In contrast,

text: surface exposure dating

text: of sediments indicate that skeleton StW 573 has an age of approximately 4 million years. While the flowstone dated in the uranium-lead dating has been shown to have formed later than the fossil, an age estimate of ~3 Ma suggested by the same authors  has little firm basis. The palaeomagnetic analysis  remains the most credible age estimate based on the current data as it included work on both sediments and speleothem.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: uranium-lead

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-lead dating

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating measure when the organism died

answers: NDQ_005717

answers: while the flowstone dated in the uranium-lead dating has been shown to have formed later than the fossil

answers: NDQ_005718

answers: an age estimate of  3 Ma suggested by the same authors has little firm basis

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: electron spin resonance dating

answers: NDQ_005712

answers: 2.6 and 2.0 Ma,

answers: NDQ_005713

answers: electron spin resonance dating

answers: NDQ_005714

answers: electron spin resonance dating

answers: NDQ_005715

answers: electron spin resonance dating

answers: NDQ_005716

answers: electron spin resonance dating

answers: NDQ_005717

answers: flowstone

answers: NDQ_005718

answers: little firm basis.

answers: NDQ_005719

answers: electron spin resonance dating

answers: NDQ_005720

answers: electron spin resonance dating

text: Potassium argon dating in the region provides an age of 1095 - 1155 Ma for the Muskox intrusion, 1100 - 1200 Ma for the Mackenzie dike swarm and 740 - 1200 Ma for the Coppermine basalt flows (younger dates are interpreted as having been reset by later intrusion of gabbro sills at 604 - 718 Ma). Further stratigraphic and structural evidence provides further support that the Muskox, the MacKenzie dikes and the Coppermine flows are of the same magmatic event that formed the Mackenzie Large Igneous Province and the Muskox is interpreted as occupying the magma chamber which fed the volcanism.

text: Potassium argon dating

text: in the region provides an age of 1095 - 1155 Ma for the Muskox intrusion, 1100 - 1200 Ma for the

text: Mackenzie dike swarm

text: and 740 - 1200 Ma for the Coppermine basalt flows (younger dates are interpreted as having been reset by later intrusion of gabbro sills at 604 - 718 Ma). Further stratigraphic and structural evidence provides further support that the Muskox, the MacKenzie dikes and the Coppermine flows are of the same magmatic event that formed the

text: Mackenzie Large Igneous Province

text: and the Muskox is interpreted as occupying the magma chamber which fed the volcanism.

answers: NDQ_005711

answers: potassium argon

answers: NDQ_005712

answers: Potassium argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: Carbon dating measures when the organism died

answers: NDQ_005717

answers: age of 1095 - 1155 Ma

answers: NDQ_005718

answers: radiometric dating is not reliable

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium argon

answers: NDQ_005712

answers: Potassium argon

answers: NDQ_005713

answers: Potassium argon

answers: NDQ_005714

answers: Potassium argon

answers: NDQ_005715

answers: Potassium argon

answers: NDQ_005716

answers: Potassium argon

answers: NDQ_005717

answers: 1095 - 1155 Ma

answers: NDQ_005718

answers: (younger dates

answers: NDQ_005719

answers: Potassium argon

answers: NDQ_005720

answers: Potassium argon

text: The cause of the Late Triassic extinction is uncertain. It was accompanied by huge volcanic eruptions that occurred as the supercontinent Pangaea began to break apart about 202 to 191 million years ago (40Ar/39Ar dates), forming the Central Atlantic Magmatic Province (CAMP), one of the largest known inland volcanic events since the planet had first cooled and stabilized. Other possible but less likely causes for the extinction events include global cooling or even a bolide impact, for which an impact crater containing Manicouagan Reservoir in Quebec, Canada, has been singled out. However, the Manicouagan  impact melt  has been dated to 214±1 Mya. The date of the Triassic-Jurassic boundary has also been more accurately fixed recently, at  Mya. Both dates are gaining accuracy by using more accurate forms of radiometric dating, in particular the decay of uranium to lead in zircons formed at time of the impact. So, the evidence suggests the Manicouagan impact preceded the end of the Triassic by approximately 10±2 Ma. It could, therefor, not be the immediate cause of the observed mass extinction.

text: The cause of the Late Triassic extinction is uncertain. It was accompanied by huge

text: volcanic

text: eruptions that occurred as the supercontinent Pangaea began to break apart about 202 to 191 million years ago (40Ar/39Ar dates), forming the

text: Central Atlantic Magmatic Province

text: (CAMP), one of the largest known inland volcanic events since the planet had first cooled and stabilized. Other possible but less likely causes for the extinction events include global cooling or even a

text: bolide

text: impact, for which an impact crater containing

text: Manicouagan Reservoir

text: in

text: Quebec

text: Canada

text: , has been singled out. However, the Manicouagan  impact melt  has been dated to 214±1 Mya. The date of the Triassic-Jurassic boundary has also been more accurately fixed recently, at  Mya. Both dates are gaining accuracy by using more accurate forms of radiometric dating, in particular the decay of uranium to lead in zircons formed at time of the impact. So, the evidence suggests the Manicouagan impact preceded the end of the Triassic by approximately 10±2 Ma. It could, therefor, not be the immediate cause of the observed mass extinction.

answers: NDQ_005711

answers: decay of uranium

answers: NDQ_005712

answers: decay of uranium to lead

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: 40Ar/39Ar dates

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: decay of uranium to lead

answers: NDQ_005718

answers: decay of uranium to lead

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: decay of uranium

answers: NDQ_005712

answers: decay of uranium to lead in zircons

answers: NDQ_005713

answers: decay of uranium to lead in zircons

answers: NDQ_005714

answers: decay of uranium to lead in zircons

answers: NDQ_005715

answers: uranium to lead

answers: NDQ_005716

answers: decay of uranium

answers: NDQ_005717

answers: decay of uranium to lead in zircons

answers: NDQ_005718

answers: decay of uranium to lead in zircons

answers: NDQ_005719

answers: zircons

answers: NDQ_005720

answers: decay of uranium to lead

text: Since the euro was first issued in 2002, the countries which have an issue date stipulation are all dated 2002 onward, even though these coins were minted in previous years to prepare for the adoption of the euro. As a result, there are no euro coins dated 1999, 2000 and 2001 issued from countries with an issue date stipulation.Luxembourg has no domestic mint, so their coins are minted elsewhere. Regardless of the mintage location of these coins, the issue date stipulation in their coinage act must be followed by whichever country mints their coins and the date stamp is therefore applied accordingly.Since Monaco, San Marino and the Vatican City do not have their own coinage acts, the date stamp is applied in accordance with the coinage act of whichever country mints these coins. France produces the euro coins for Monaco and follows the mintage date stipulation; it began minting Monégasque euro coins only in 2001, since the mintage quantities were so low. Sammarinese and Vatican euro coins are minted in Italy and follow the issue date stipulation.

text: Since the euro was first issued in 2002, the countries which have an issue date stipulation are all dated 2002 onward, even though these coins were minted in previous years to prepare for the adoption of the euro. As a result, there are no euro coins dated 1999, 2000 and 2001 issued from countries with an issue date stipulation.Luxembourg has no domestic mint, so their coins are minted elsewhere. Regardless of the mintage location of these coins, the issue date stipulation in their coinage act must be followed by whichever country mints their coins and the date stamp is therefore applied accordingly.Since Monaco, San Marino and the Vatican City do not have their own coinage acts, the date stamp is applied in accordance with the coinage act of whichever country mints these coins. France produces the euro coins for Monaco and follows the mintage date stipulation; it began minting Monégasque euro coins only in 2001, since the mintage quantities were so low. Sammarinese and Vatican euro coins are minted in Italy and follow the issue date stipulation.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: the date stamp is applied in accordance with the coinage act

answers: NDQ_005718

answers: no euro coins dated 1999, 2000 and 2001

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: date stamp

answers: NDQ_005712

answers: 2002 onward,

answers: NDQ_005713

answers: Since the euro was first issued in 2002,

answers: NDQ_005714

answers: Since the euro was first issued in 2002,

answers: NDQ_005715

answers: Since the euro was first issued in 2002,

answers: NDQ_005716

answers: date stamp

answers: NDQ_005717

answers: 2002 onward,

answers: NDQ_005718

answers: mintage quantities were so low.

answers: NDQ_005719

answers: Since the euro was first issued in 2002,

answers: NDQ_005720

answers: Since the euro was first issued in 2002,

text: Furthermore,  extends the content of the state of the art by also including "the content of European patent applications as filed, the dates of filing of which are prior to the date referred to in paragraph 2 and which were published on or after that date". The purpose of this notional extension of the state of the art under the European Patent Convention is to address conflicting prior rights which might otherwise, without Article 54(3) EPC, lead to more than one patent granted for the same invention to different inventors. The extension of the definition of the state of the art under Article 54(3) EPC is limited to the assessment of novelty and does not apply to the assessment of inventive step. In other words, "documents within the meaning of Article 54(3) EPC are not to be considered in deciding on inventive step".

text: Furthermore,  extends the content of the state of the art by also including "the content of European patent applications as filed, the dates of filing of which are prior to the date referred to in paragraph 2 and which were published on or after that date". The purpose of this notional extension of the state of the art under the European Patent Convention is to address conflicting prior rights which might otherwise, without Article 54(3) EPC, lead to more than one patent granted for the same invention to different inventors. The extension of the definition of the state of the art under Article 54(3) EPC is limited to the assessment of novelty and does not apply to the assessment of inventive step. In other words, "documents within the meaning of Article 54(3) EPC are not to be considered in deciding on inventive step".

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: is limited to the assessment of novelty

answers: NDQ_005718

answers: not to be considered in deciding on inventive step

answers: NDQ_005719

answers: uranium-lead

answers: NDQ_005720

answers: NDQ_005711

answers: prior to the date referred to in paragraph 2

answers: NDQ_005712

answers: novelty

answers: NDQ_005713

answers: novelty and does not apply to the assessment of inventive step.

answers: NDQ_005714

answers: to address conflicting prior rights

answers: NDQ_005715

answers: novelty and does not apply to the assessment of inventive step.

answers: NDQ_005716

answers: novelty and does not apply to the assessment of inventive step.

answers: NDQ_005717

answers: novelty and does not apply to the assessment of inventive step.

answers: NDQ_005718

answers: assessment of novelty and does not apply to the assessment of inventive step.

answers: NDQ_005719

answers: novelty and does not apply to the assessment of inventive step.

answers: NDQ_005720

answers: novelty and does not apply to the assessment of inventive step.

text: Radiometric dating is based on the known and constant rate of decay of radioactive isotopes into their radiogenic daughter isotopes. Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age. For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their  decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.

text: Radiometric dating is based on the known and constant rate of decay of

text: radioactive isotopes

text: into their

text: radiogenic daughter isotopes

text: . Particular isotopes are suitable for different applications due to the type of atoms present in the mineral or other material and its approximate age. For example, techniques based on isotopes with half lives in the thousands of years, such as Carbon-14, cannot be used to date materials that have ages on the order of billions of years, as the detectable amounts of the radioactive atoms and their  decayed daughter isotopes will be too small to measure within the uncertainty of the instruments.

answers: NDQ_005711

answers: known and constant rate of decay

answers: NDQ_005712

answers: isotopes are suitable for different applications

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: half lives in the thousands of years

answers: NDQ_005715

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: rate of decay of radioactive isotopes into their radiogenic daughter isotopes

answers: NDQ_005718

answers: cannot be used to date materials that have ages on the order of billions of years

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: the known and constant rate of decay of radioactive isotopes

answers: NDQ_005712

answers: detectable amounts of the radioactive atoms

answers: NDQ_005713

answers: radiogenic daughter isotopes.

answers: NDQ_005714

answers: thousands of years,

answers: NDQ_005715

answers: thousands of years,

answers: NDQ_005716

answers: Carbon-14,

answers: NDQ_005717

answers: known and constant rate of decay of radioactive isotopes

answers: NDQ_005718

answers: uncertainty of the instruments.

answers: NDQ_005719

answers: thousands of years,

answers: NDQ_005720

answers: Carbon-14,

text: The dating of the rock type section of the Ediacaran Period in South Australia has proven uncertain. Therefore, the age range assigned those rocks from 635 to 542 million years, is based on more precice dating in other locations is possible. The base age of approximately 635 million years is based on U-Pb (uranium-lead) isochron dating from Namibia and China.

text: The

text: dating

text: of the rock type section of the Ediacaran Period in South Australia has proven uncertain. Therefore, the age range assigned those rocks from 635 to 542 million years, is based on more precice dating in other locations is possible. The base age of approximately 635 million years is based on U-Pb (

text: uranium

text: lead

text: isochron dating

text: from

text: Namibia

text: and China.

answers: NDQ_005711

answers: U-Pb

answers: NDQ_005712

answers: U-Pb

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: U-Pb isochron dating from Namibia and China

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: U-Pb

answers: NDQ_005717

answers: The base age of approximately 635 million years is based on U-Pb

answers: NDQ_005718

answers: uncertain

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: (uranium-lead) isochron

answers: NDQ_005712

answers: more precice dating in other locations is possible.

answers: NDQ_005713

answers: 635 to 542 million years,

answers: NDQ_005714

answers: more precice dating in other locations is possible.

answers: NDQ_005715

answers: 635 to 542 million years,

answers: NDQ_005716

answers: age range assigned those rocks from 635 to 542 million years,

answers: NDQ_005717

answers: U-Pb

answers: NDQ_005718

answers: uncertain.

answers: NDQ_005719

answers: U-Pb

answers: NDQ_005720

answers: U-Pb

text: As with many sloth fossils, these species of sloth have not been radiometrically dated. It is suggested that the Puerto Rican and Hispaniolan Acratocnus species survived into the late Pleistocene but disappeared by the mid-Holocene.  The related Cuban ground sloth, Megalocnus rodens, survived until at least c. 6600 BP, and the latest survival reported for any of the Antillean sloths is c. 5000 BP, for the Hispaniolan Neocnus comes, based on AMS radiocarbon dating. The cause(s) of their extinctions may have been climatic changes, or more likely, human hunting.

text: As with many sloth fossils, these species of sloth have not been radiometrically dated. It is suggested that the Puerto Rican and Hispaniolan Acratocnus species survived into the late

text: Pleistocene

text: but disappeared by the mid-

text: Holocene

text: .  The related Cuban ground sloth,

text: Megalocnus

text: rodens, survived until at least c. 6600

text: BP

text: , and the latest survival reported for any of the Antillean sloths is c. 5000 BP, for the

text: Hispaniola

text: n Neocnus comes, based on

text: AMS

text: radiocarbon dating

text: . The cause(s) of their extinctions may have been climatic changes, or more likely, human hunting.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: AMS radiocarbon dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: AMS radiocarbon dating

answers: NDQ_005715

answers: How long does carbon-14 decay?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: AMS radiocarbon dating

answers: NDQ_005718

answers: these species of sloth have not been radiometrically dated

answers: NDQ_005719

answers: How is radiometric dating used?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: AMS radiocarbon

answers: NDQ_005713

answers: AMS radiocarbon dating.

answers: NDQ_005714

answers: AMS

answers: NDQ_005715

answers: mid-Holocene.

answers: NDQ_005716

answers: AMS radiocarbon dating.

answers: NDQ_005717

answers: AMS

answers: NDQ_005718

answers: many sloth fossils,

answers: NDQ_005719

answers: AMS radiocarbon

answers: NDQ_005720

answers: AMS radiocarbon dating.

text: Uranium-lead dating is often performed on the mineral zircon (ZrSiO), though it can be used on other materials, such as baddeleyite, as well as monazite (see: monazite geochronology). Zircon and baddeleyite incorporate uranium atoms into their crystalline structure as substitutes for zirconium, but strongly reject lead. Zircon has a very high closure temperature, is resistant to mechanical weathering and is very chemically inert. Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. In situ micro-beam analysis can be achieved via laser ICP-MS or SIMS techniques.

text: Uranium-lead dating is often performed on the

text: mineral

text: zircon

text: (ZrSiO), though it can be used on other materials, such as

text: baddeleyite

text: , as well as

text: monazite

text: (see:

text: monazite geochronology

text: ). Zircon and baddeleyite incorporate uranium atoms into their crystalline structure as substitutes for

text: zirconium

text: , but strongly reject lead. Zircon has a very high closure temperature, is resistant to mechanical weathering and is very chemically inert. Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. In situ micro-beam analysis can be achieved via laser

entity_name: Inductively coupled plasma mass spectrometry

text: ICP-MS

text: or

text: SIMS

text: techniques.

answers: NDQ_005711

answers: Uranium-lead

answers: NDQ_005712

answers: Zircon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Zircon has a very high closure temperature

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: Zircon

answers: NDQ_005717

answers: Zircon has a very high closure temperature

answers: NDQ_005718

answers: isotopic age of the event

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Uranium-lead

answers: NDQ_005712

answers: isotopic age

answers: NDQ_005713

answers: Uranium-lead dating

answers: NDQ_005714

answers: Uranium-lead dating

answers: NDQ_005715

answers: zircon

answers: NDQ_005716

answers: Uranium-lead dating

answers: NDQ_005717

answers: strongly reject lead.

answers: NDQ_005718

answers: strongly reject lead.

answers: NDQ_005719

answers: zircon

answers: NDQ_005720

answers: zircon (ZrSiO),

text: Common isotopic systems used for thermochronology include fission track dating in zircon and apatite, potassium-argon and argon-argon dating in apatite, uranium-thorium-helium dating in zircon and apatite, and He/He dating.

text: Common isotopic systems used for thermochronology include

text: fission track dating

text: in

text: zircon

text: and

text: apatite

text: potassium-argon

text: and

text: argon-argon

text: dating in apatite, uranium-thorium-helium dating in zircon and apatite, and He/He dating.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: zircon and apatite

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a stable isotope

answers: NDQ_005715

answers: NDQ_005716

answers: fission track

answers: NDQ_005717

answers: apatite

answers: NDQ_005718

answers: thermochronology

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: thermochronology

answers: NDQ_005712

answers: thermochronology

answers: NDQ_005713

answers: He/He dating.

answers: NDQ_005714

answers: thermochronology

answers: NDQ_005715

answers: He/He dating.

answers: NDQ_005716

answers: thermochronology

answers: NDQ_005717

answers: apatite,

answers: NDQ_005718

answers: thermochronology

answers: NDQ_005719

answers: argon-argon dating in apatite,

answers: NDQ_005720

answers: uranium-thorium-helium

text: The territory of Vietnam is divided into five structural blocks : Northeast (NE), Northwest (NW), Truongson, Kon Tum and Nambo. The NE block is a part of the South China plate, in which strata and igneous rocks have been found dating from the Early Paleozoic to the Quaternary. The NW and Truongson blocks are regarded as NW-SE trending Paleozoic folded systems filled with thick (>12000 m) Paleozoic formations. Precambrian strata are widespread in the Red River Fault zone and Fansipan range in the NW block, and in the Kon Tum block. Archean rocks are found only in the Kon Tum block, which is regarded as a stable massif without Paleozoic sedimentary rocks. The Nambo block is covered with a very thick (>6000 m) sequence of Cenozoic formations deposited in a continental rift. During the Mesozoic many such graben structures were formed and become basins for sedimentation. Igneous activity in Vietnam is divided into five episodes from the Archean to Quaternary. The most important impediments to the description and interpretation of geology in Vietnam are lack of reliable radiometric and structural data, and scarcity of good outcrops.

text: The territory of

text: Vietnam

text: is divided into five structural blocks : Northeast (NE), Northwest (NW),

text: Truongson

text: , Kon Tum and Nambo. The NE block is a part of the

text: South China plate

text: , in which

text: strata

text: and

text: igneous

text: rocks have been found dating from the Early

text: Paleozoic

text: to the

text: Quaternary

text: . The NW and Truongson blocks are regarded as NW-SE trending Paleozoic folded systems filled with thick (>12000 m) Paleozoic formations.

text: Precambrian

text: strata are widespread in the

text: Red River Fault

text: zone and

text: Fansipan

text: range in the NW block, and in the Kon Tum block.

text: Archean

text: rocks are found only in the Kon Tum block, which is regarded as a stable massif without Paleozoic sedimentary rocks. The Nambo block is covered with a very thick (>6000 m) sequence of

text: Cenozoic

text: formations deposited in a continental rift. During the

text: Mesozoic

text: many such

text: graben

text: structures were formed and become basins for

text: sedimentation

text: . Igneous activity in Vietnam is divided into five episodes from the Archean to Quaternary. The most important impediments to the description and interpretation of

text: geology

text: in Vietnam are lack of reliable radiometric and structural data, and scarcity of good

text: outcrop

text: s.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Paleozoic

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating measures when the organism died

answers: NDQ_005717

answers: radiometric data, and scarcity of good outcrops.

answers: NDQ_005718

answers: reliable radiometric and structural data

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: Early Paleozoic to the Quaternary.

answers: NDQ_005712

answers: Early Paleozoic to the Quaternary.

answers: NDQ_005713

answers: lack of reliable radiometric and structural data,

answers: NDQ_005714

answers: lack of reliable radiometric

answers: NDQ_005715

answers: lack of reliable radiometric and structural data,

answers: NDQ_005716

answers: dating from the Early Paleozoic to the Quaternary.

answers: NDQ_005717

answers: Early Paleozoic to the Quaternary.

answers: NDQ_005718

answers: lack of reliable radiometric and structural data,

answers: NDQ_005719

answers: Early Paleozoic to the Quaternary.

answers: NDQ_005720

answers: Early Paleozoic to the Quaternary.

text: Around 99.284% of natural uranium is uranium-238, which has a half-life of 1.41 seconds (4.468 years, or 4.468 billion years).Depleted uranium has an even higher concentration of the U isotope, and even low-enriched uranium (LEU), while having a higher proportion of the uranium-235 isotope (in comparison to depleted uranium), is still mostly U. Reprocessed uranium is also mainly U, with about as much uranium-235 as natural uranium, a comparable proportion of uranium-236, and much smaller amounts of other isotopes of uranium such as uranium-234, uranium-233, and uranium-232.

text: Around 99.284% of

text: natural uranium

text: is uranium-238, which has a half-life of 1.41

text: second

text: s (4.468 years, or 4.468 billion years).

text: Depleted uranium

text: has an even higher concentration of the U isotope, and even

text: low-enriched uranium

text: (LEU), while having a higher proportion of the

text: isotope (in comparison to depleted uranium), is still mostly U.

text: Reprocessed uranium

text: is also mainly U, with about as much

text: as natural uranium, a comparable proportion of

text: , and much smaller amounts of other

text: isotopes of uranium

text: such as

text: , and

answers: NDQ_005711

answers: half-life

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 has a half-life of 1.41 seconds

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: uranium-238

answers: NDQ_005717

answers: uranium-235

answers: NDQ_005718

answers: half-life of 1.41 seconds

answers: NDQ_005719

answers: Why is potassium-argon dating useful for very young materials?

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: half-life

answers: NDQ_005712

answers: half-life

answers: NDQ_005713

answers: (4.468 years, or 4.468 billion years).Depleted

answers: NDQ_005714

answers: uranium is uranium-238,

answers: NDQ_005715

answers: 4.468 billion years).Depleted

answers: NDQ_005716

answers: half-life

answers: NDQ_005717

answers: 1.41 seconds

answers: NDQ_005718

answers: half-life of 1.41 seconds

answers: NDQ_005719

answers: uranium-238,

answers: NDQ_005720

answers: uranium-238,

text: A volcanic ash exposed in the lake shale beds was originally radiometrically dated using the K-Ar method at ~51 million years ago; however, a recently provided radiometric date using the Ar-Ar method places the McAbee Fossil Beds at 52.9 ± 0.83 million years old, placing it in the early Eocene Epoch.

text: A volcanic ash exposed in the lake shale beds was originally

text: radiometrically dated

text: using the

text: K-Ar

text: method at ~51 million years ago; however, a recently provided radiometric date using the

text: Ar-Ar

text: method places the McAbee Fossil Beds at 52.9 ± 0.83 million years old, placing it in the

text: early Eocene

text: Epoch.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 51 million years ago

answers: NDQ_005718

answers: 51 million years ago

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: K-Ar method

answers: NDQ_005712

answers: early Eocene Epoch.

answers: NDQ_005713

answers: K-Ar method

answers: NDQ_005714

answers: K-Ar

answers: NDQ_005715

answers: K-Ar

answers: NDQ_005716

answers: radiometrically dated using the K-Ar

answers: NDQ_005717

answers: <unk>51 million years ago;

answers: NDQ_005718

answers: 51 million years ago;

answers: NDQ_005719

answers: K-Ar method

answers: NDQ_005720

answers: K-Ar method

text: Antoine Zazzo has since carried out radiocarbon dating of the human remains using apatite, although he stresses the ages obtained should be treated with caution "...because the reliability of the reference age, a bone collagen sample dated in the late 60's or very early 70's, i.e.well before the advent of modern purification techniques, and in a site where collagen preservation is very poor, remains questionable." Nevertheless, the combination of the dates obtained by Antoine, and Wendorf's own assessment of the likely age of the remains, are a strong indication that the age of the human remains in the cemetery must be either a little older or similar to that of Nataruk.

text: Antoine Zazzo has since carried out radiocarbon dating of the human remains using apatite, although he stresses the ages obtained should be treated with caution "...because the reliability of the reference age, a bone collagen sample dated in the late 60's or very early 70's, i.e.well before the advent of modern purification techniques, and in a site where collagen preservation is very poor, remains questionable." Nevertheless, the combination of the dates obtained by Antoine, and Wendorf's own assessment of the likely age of the remains, are a strong indication that the age of the human remains in the cemetery must be either a little older or similar to that of Nataruk.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: the reliability of the reference age

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: i.e.well before the advent of modern purification techniques,

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: apatite,

answers: NDQ_005715

answers: apatite,

answers: NDQ_005716

answers: apatite,

answers: NDQ_005717

answers: apatite,

answers: NDQ_005718

answers: reliability of the reference age,

answers: NDQ_005719

answers: late 60's or very early 70's,

answers: NDQ_005720

answers: apatite,

text: The maximum age of the Unkar Group is also established by uranium-lead (U-Pb) dating of zircons from an ash bed from the Bass Formation in the basal Unkar Group of 1254 Ma near river Mile 78 (List of Colorado River rapids and features). The dating of detrital zircons from the Bass Formation have yielded dates of about 1200 Ma. These dates suggest that the 1254 Ma age may be a bit too old. However, these zircons likely underwent some lead loss, and, as a result these apparent dates are younger than their actual ages. As a result, the 1254 Ma dates remain the best estimate for the age of initial deposition of the Unkar Group.

text: The maximum age of the Unkar Group is also established by

text: uranium-lead

text: (U-Pb)

text: dating

text: of

text: zircon

text: s from an ash bed from the Bass Formation in the basal Unkar Group of 1254 Ma near river Mile 78 (

entity_name: List of Colorado River rapids and features

text: List of Colorado River rapids and features

text: ). The dating of detrital zircons from the Bass Formation have yielded dates of about 1200 Ma. These dates suggest that the 1254 Ma age may be a bit too old. However, these zircons likely underwent some lead loss, and, as a result these apparent dates are younger than their actual ages. As a result, the 1254 Ma dates remain the best estimate for the age of initial deposition of the Unkar Group.

answers: NDQ_005711

answers: U-Pb

answers: NDQ_005712

answers: these zircons likely underwent some lead loss

answers: NDQ_005713

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating measure when the organism died

answers: NDQ_005717

answers: the 1254 Ma dates remain the best estimate for the age of initial deposition

answers: NDQ_005718

answers: these zircons likely underwent some lead loss

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead

answers: NDQ_005712

answers: these zircons likely underwent some lead loss,

answers: NDQ_005713

answers: uranium-lead

answers: NDQ_005714

answers: lead loss,

answers: NDQ_005715

answers: 1254 Ma near river Mile 78

answers: NDQ_005716

answers: lead loss,

answers: NDQ_005717

answers: uranium-lead

answers: NDQ_005718

answers: these zircons likely underwent some lead loss,

answers: NDQ_005719

answers: 1200 Ma.

answers: NDQ_005720

answers: 1254 Ma

text: Eruption of the Siletzia basalts has been placed roughly in the late Paleocene through the mid Eocene; more specific dates have been difficult to obtain and somewhat variable.  Early K-Ar (potassium-argon) and Ar-Ar (argon-argon) radiometric dating by Duncan gave dates of 57 and 62 Ma (million years ago) to the northern and southern ends, and a date of 49 Ma for the Grays River volcanics near the center of Siletzia. This is suggestive of a spreading ridge (as previously noted by ), and has been a strong constraint on models of how Siletzia formed. Other researchers have since found younger dates (50-48 Ma) for the Crescent basalts, removing much of the age symmetry.

text: Eruption of the Siletzia basalts has been placed roughly in the late

text: Paleocene

text: through the mid

text: Eocene

text: ; more specific dates have been difficult to obtain and somewhat variable.  Early K-Ar (potassium-argon) and Ar-Ar (argon-argon)

text: radiometric dating

text: by Duncan gave dates of 57 and 62 Ma (million years ago) to the northern and southern ends, and a date of 49 Ma for the Grays River volcanics near the center of Siletzia. This is suggestive of a

text: spreading ridge

text: (as previously noted by ), and has been a strong constraint on models of how Siletzia formed. Other researchers have since found younger dates (50-48 Ma) for the Crescent basalts, removing much of the age symmetry.

answers: NDQ_005711

answers: K-Ar

answers: NDQ_005712

answers: K-Ar

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: K-Ar

answers: NDQ_005715

answers: How long does carbon-14 decay to carbon-12?

answers: NDQ_005716

answers: carbon dating measures when the organism died

answers: NDQ_005717

answers: 57 and 62 Ma

answers: NDQ_005718

answers: specific dates have been difficult to obtain

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: K-Ar (potassium-argon)

answers: NDQ_005712

answers: age symmetry.

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: K-Ar (potassium-argon)

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: K-Ar

answers: NDQ_005718

answers: variable.

answers: NDQ_005719

answers: K-Ar

answers: NDQ_005720

answers: K-Ar

text: Body fossils and trace fossils are the principal types of evidence about ancient life, and geochemical evidence has helped to decipher the evolution of life before there were organisms large enough to leave body fossils. Estimating the dates of these remains is essential but difficult: sometimes adjacent rock layers allow radiometric dating, which provides absolute dates that are accurate to within 0.5%, but more often paleontologists have to rely on relative dating by solving the "jigsaw puzzles" of biostratigraphy. Classifying ancient organisms is also difficult, as many do not fit well into the Linnaean taxonomy that is commonly used for classifying living organisms, and paleontologists more often use cladistics to draw up evolutionary "family trees". The final quarter of the 20th century saw the development of molecular phylogenetics, which investigates how closely organisms are related by measuring how similar the DNA is in their genomes. Molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the molecular clock on which such estimates depend.

text: Body fossils and

text: trace fossil

text: s are the principal types of evidence about ancient life, and

text: geochemical

text: evidence has helped to decipher the evolution of life before there were organisms large enough to leave body fossils. Estimating the dates of these remains is essential but difficult: sometimes adjacent rock layers allow

text: radiometric dating

text: , which provides

text: absolute dates

text: that are accurate to within 0.5%, but more often paleontologists have to rely on relative dating by solving the "

text: jigsaw puzzle

text: s" of

text: biostratigraphy

text: . Classifying ancient organisms is also difficult, as many do not fit well into the

text: Linnaean taxonomy

text: that is commonly used for classifying living organisms, and paleontologists more often use

text: cladistics

text: to draw up evolutionary "family trees". The final quarter of the 20th century saw the development of

text: molecular phylogenetics

text: , which investigates how closely organisms are related by measuring how similar the

text: DNA

text: is in their

text: genome

text: s. Molecular phylogenetics has also been used to estimate the dates when species diverged, but there is controversy about the reliability of the

text: molecular clock

text: on which such estimates depend.

answers: NDQ_005711

answers: adjacent rock layers

answers: NDQ_005712

answers: adjacent rock layers

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: absolute dates that are accurate to within 0.5%

answers: NDQ_005718

answers: accuracy to within 0.5%

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: adjacent rock layers

answers: NDQ_005712

answers: adjacent rock layers

answers: NDQ_005713

answers: radiometric dating, which provides absolute dates that are accurate to within 0.5%,

answers: NDQ_005714

answers: absolute dates that are accurate to within 0.5%,

answers: NDQ_005715

answers: molecular phylogenetics,

answers: NDQ_005716

answers: body fossils.

answers: NDQ_005717

answers: absolute dates that are accurate to within 0.5%,

answers: NDQ_005718

answers: more often paleontologists have to rely on relative dating

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: radiometric dating, which provides absolute dates that are accurate to within 0.5%,

text: Uranium–lead (U–Pb) dating is one of the oldest and most refined of the radiometric dating schemes.  It can be used to date rocks that formed from about 1 million years to over 4.5 billion years ago with routine precisions in the 0.1–1 percent range.

text: Uranium–lead (U–Pb) dating is one of the oldest and most refined of the

text: radiometric dating

text: schemes.  It can be used to date rocks that formed from about 1 million years to over 4.5 billion years ago with routine precisions in the 0.1–1 percent range.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium–lead

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium–lead

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: can be used to date rocks that formed from about 1 million years to over 4.5 billion years

answers: NDQ_005718

answers: precisions in the 0.1–1 percent range

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 0.1–1 percent range.

answers: NDQ_005712

answers: from about 1 million years to over 4.5 billion years ago

answers: NDQ_005713

answers: Uranium–lead

answers: NDQ_005714

answers: radiometric dating schemes.

answers: NDQ_005715

answers: Uranium–lead

answers: NDQ_005716

answers: Uranium–lead

answers: NDQ_005717

answers: 0.1–1 percent range.

answers: NDQ_005718

answers: 0.1–1 percent range.

answers: NDQ_005719

answers: 1 million years to over 4.5 billion years ago

answers: NDQ_005720

answers: 4.5 billion years ago

text: Absolute radiometric dating requires a measurable fraction of parent nucleus to remain in the sample rock. For rocks dating back to the beginning of the solar system, this requires extremely long-lived parent isotopes, making measurement of such rocks' exact ages imprecise. To be able to distinguish the relative ages of rocks from such old material, and to get a better time resolution than that available from long-lived isotopes, short-lived isotopes that are no longer present in the rock can be used.

text: Absolute radiometric dating requires a measurable fraction of parent nucleus to remain in the sample rock. For rocks dating back to the beginning of the solar system, this requires extremely long-lived parent isotopes, making measurement of such rocks' exact ages imprecise. To be able to distinguish the relative ages of rocks from such old material, and to get a better time resolution than that available from long-lived isotopes, short-lived isotopes that are no longer present in the rock can be used.

answers: NDQ_005711

answers: Absolute

answers: NDQ_005712

answers: this requires extremely long-lived parent isotopes

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Absolute radiometric dating

answers: NDQ_005715

answers: NDQ_005716

answers: Absolute radiometric dating

answers: NDQ_005717

answers: requires a measurable fraction of parent nucleus to remain in the sample rock

answers: NDQ_005718

answers: this requires extremely long-lived parent isotopes

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: a measurable fraction of parent nucleus to remain in the sample rock.

answers: NDQ_005712

answers: short-lived isotopes

answers: NDQ_005713

answers: short-lived isotopes

answers: NDQ_005714

answers: to get a better time resolution

answers: NDQ_005715

answers: short-lived isotopes

answers: NDQ_005716

answers: Absolute radiometric dating

answers: NDQ_005717

answers: short-lived isotopes

answers: NDQ_005718

answers: extremely long-lived parent isotopes,

answers: NDQ_005719

answers: short-lived isotopes

answers: NDQ_005720

answers: short-lived isotopes

text: Today the Blytt-Sernander sequence has been substantiated by a wide variety of scientific dating methods, mainly radiocarbon dates obtained from peat. Earlier radiocarbon dates were often left uncalibrated; that is, they were derived by assuming a constant concentration of atmospheric radiocarbon. In fact the atmospheric radiocarbon concentration has varied over time and thus radiocarbon dates need to be calibrated.

text: Today the Blytt-Sernander sequence has been substantiated by a wide variety of scientific dating methods, mainly

text: radiocarbon

text: dates obtained from peat. Earlier radiocarbon dates were often left uncalibrated; that is, they were derived by assuming a constant concentration of atmospheric radiocarbon. In fact the atmospheric radiocarbon concentration has varied over time and thus radiocarbon dates need to be

text: calibrated

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: the atmospheric radiocarbon concentration has varied over time

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: the atmospheric radiocarbon concentration has varied over time

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: assuming a constant concentration of atmospheric radiocarbon.

answers: NDQ_005712

answers: atmospheric radiocarbon concentration has varied over time

answers: NDQ_005713

answers: radiocarbon dates need to be calibrated.

answers: NDQ_005714

answers: the atmospheric radiocarbon concentration has varied over time

answers: NDQ_005715

answers: radiocarbon dates need to be calibrated.

answers: NDQ_005716

answers: radiocarbon dates obtained from peat.

answers: NDQ_005717

answers: assuming a constant concentration of atmospheric radiocarbon.

answers: NDQ_005718

answers: the atmospheric radiocarbon concentration has varied over time

answers: NDQ_005719

answers: radiocarbon dates obtained from peat.

answers: NDQ_005720

answers: radiocarbon dates obtained from peat.

text: Initial attempts were made in 1974 by Maurice Taieb and James Aronson in Aronson's laboratory at Case Western Reserve University to estimate the age of the fossils using the potassium-argon radiometric dating method. These efforts  were hindered by several factors: the rocks in the recovery area were chemically altered or reworked by volcanic activity; datable crystals were very scarce in the sample material; and there was a complete absence of pumice clasts at Hadar. (The Lucy skeleton occurs in the part of the Hadar sequence that accumulated with the fastest rate of deposition, which partly accounts for her excellent preservation.)

text: Initial attempts were made in 1974 by Maurice Taieb and James Aronson in Aronson's laboratory at

text: Case Western Reserve University

text: to estimate the age of the fossils using the

text: potassium-argon radiometric dating method

text: . These efforts  were hindered by several factors: the rocks in the recovery area were chemically altered or reworked by volcanic activity; datable crystals were very scarce in the sample material; and there was a complete absence of pumice clasts at Hadar. (The Lucy skeleton occurs in the part of the Hadar sequence that accumulated with the fastest rate of deposition, which partly accounts for her excellent preservation.)

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: potassium-argon radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: initial attempts were made in 1974

answers: NDQ_005718

answers: volcanic activity

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: potassium-argon radiometric dating method.

answers: NDQ_005714

answers: potassium-argon radiometric dating method.

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: datable crystals

answers: NDQ_005717

answers: datable crystals were very scarce in the sample material;

answers: NDQ_005718

answers: datable crystals were very scarce in the sample material;

answers: NDQ_005719

answers: potassium-argon radiometric dating

answers: NDQ_005720

answers: potassium-argon

text: Liquid argon is used as the target for neutrino experiments and direct dark matter searches. The interaction between the hypothetical WIMP particle and an argon nucleus produces scintillation light that is detected by photomultiplier tubes. Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP-nucleus scattering. As with most other liquefied noble gases, argon has a high scintillation light yield (c. 51 photons/keV), is transparent to its own scintillation light, and is relatively easy to purify. Compared to xenon, argon is cheaper and has a distinct scintillation time profile which allows the separation of electronic recoils from nuclear recoils.  On the other hand, its intrinsic beta-ray background is larger due to  contamination, unless one uses argon from underground sources, which has much less  contamination. Most of the argon in the Earth’s atmosphere was produced by electron capture of long-lived  ( + e →  + ν) present in natural potassium within the earth.  The  activity in the atmosphere is maintained by cosmogenic production through (n,2n) and similar reactions.  The half-life of  is only 269 years.  As a result, the underground Ar, shielded by rock and water, has much less  contamination.  Dark matter detectors currently operating with liquid argon include DarkSide, WArP, ArDM, microCLEAN and DEAP.  Neutrino experiments include ICARUS and MicroBooNE, both of which use high purity liquid argon in a time projection chamber for fine grained three-dimensional imaging of neutrino interactions.

text: Liquid argon is used as the target for neutrino experiments and direct

text: dark matter

text: searches. The interaction between the hypothetical

text: WIMP

text: particle and an argon nucleus produces

text: scintillation

text: light that is detected by

text: photomultiplier tubes

text: . Two-phase detectors containing argon gas are used to detect the ionized electrons produced during the WIMP-nucleus scattering. As with most other liquefied noble gases, argon has a high scintillation light yield (c. 51 photons/keV), is transparent to its own scintillation light, and is relatively easy to purify. Compared to

text: xenon

text: , argon is cheaper and has a distinct scintillation time profile which allows the separation of electronic recoils from nuclear recoils.  On the other hand, its intrinsic beta-ray background is larger due to  contamination, unless one uses argon from underground sources, which has much less  contamination. Most of the argon in the Earth’s atmosphere was produced by electron capture of long-lived  ( + e →  + ν) present in natural potassium within the earth.  The  activity in the atmosphere is maintained by cosmogenic production through (n,2n) and similar reactions.  The half-life of  is only 269 years.  As a result, the underground Ar, shielded by rock and water, has much less  contamination.  Dark matter detectors currently operating with liquid argon include

text: DarkSide

text: WArP

text: ArDM

entity_name: Cryogenic Low-Energy Astrophysics with Neon

text: microCLEAN

text: and

text: DEAP

text: .  Neutrino experiments include

text: ICARUS

text: and

text: MicroBooNE

text: , both of which use high purity liquid argon in a

text: time projection chamber

text: for fine grained three-dimensional imaging of neutrino interactions.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: half-life of is only 269 years

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: half-life of is only 269 years

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: half-life of is only 269 years

answers: NDQ_005717

answers: The interaction between the hypothetical WIMP particle and an argon nucleus produces scintillation light

answers: NDQ_005718

answers: half-life of is only 269 years

answers: NDQ_005719

answers: What is the half-life of argon?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: electron capture of long-lived

answers: NDQ_005712

answers: long-lived

answers: NDQ_005713

answers: neutrino

answers: NDQ_005714

answers: by electron capture of long-lived

answers: NDQ_005715

answers: 269 years.

answers: NDQ_005716

answers: The half-life of is only 269 years.

answers: NDQ_005717

answers: The half-life of is only 269 years.

answers: NDQ_005718

answers: The half-life of is only 269 years.

answers: NDQ_005719

answers: 269 years.

answers: NDQ_005720

answers: 269 years.

text: Ar, the most abundant isotope of argon, is produced by the decay of K with a half-life of 1.25 years by electron capture or positron emission. Because of this, it is used in potassium-argon dating to determine the age of rocks.

text: Ar

text: , the most abundant

text: isotope

text: of argon, is produced by the decay of

text: K

text: with a half-life of 1.25 years by

text: electron capture

text: or

text: positron emission

text: . Because of this, it is used in

text: potassium-argon dating

text: to determine the age of rocks.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: Ar decay

answers: NDQ_005717

answers: to determine the age of rocks

answers: NDQ_005718

answers: half-life

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon dating

answers: NDQ_005712

answers: potassium-argon dating to determine the age of rocks.

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: potassium-argon dating to determine the age of rocks.

answers: NDQ_005715

answers: K

answers: NDQ_005716

answers: electron capture or positron emission.

answers: NDQ_005717

answers: to determine the age of rocks.

answers: NDQ_005718

answers: half-life of 1.25 years

answers: NDQ_005719

answers: potassium-argon dating to determine the age of rocks.

answers: NDQ_005720

answers: potassium-argon dating

text: The site has wider significance because its evidence shows the coincidence of cultural, ritual, economic and population changes over a long period of use. Finds show long-distance contacts of the communities at Klin-Yar: in the Koban period to the Black Sea, and across the Caucasus Mountains to Mesopotamia; in the Sarmatian period to the Eastern Roman Empire; and in the Alanic period to Central Asia, Iran, and the Byzantine Empire. A branch of the Silk Road is thought to have run along the Podkumok valley in the Alanic period, explaining some of the wealth and the contacts of this site. Klin–Yar is the first site in the North Caucasus where a so-called ‘reservoir effect’ in radiocarbon dating, was demonstrated in dates derived from human bones; the dates show irregular offsets caused by ancient carbon in the water of this volcanic region.

text: The site has wider significance because its evidence shows the coincidence of cultural, ritual, economic and population changes over a long period of use. Finds show long-distance contacts of the communities at Klin-Yar: in the Koban period to the Black Sea, and across the Caucasus Mountains to Mesopotamia; in the Sarmatian period to the Eastern Roman Empire; and in the Alanic period to Central Asia, Iran, and the Byzantine Empire. A branch of the

text: Silk Road

text: is thought to have run along the Podkumok valley in the Alanic period, explaining some of the wealth and the contacts of this site. Klin–Yar is the first site in the North Caucasus where a so-called ‘reservoir effect’ in

text: radiocarbon dating

text: , was demonstrated in dates derived from human bones; the dates show irregular offsets caused by ancient carbon in the water of this volcanic region.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: reservoir effect

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: was demonstrated in dates derived from human bones

answers: NDQ_005718

answers: reservoir effect

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: ancient carbon in the water of this volcanic region.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: ‘reservoir effect’

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: carbon

answers: NDQ_005717

answers: a so-called ‘reservoir effect’

answers: NDQ_005718

answers: irregular offsets

answers: NDQ_005719

answers: radiocarbon dating,

answers: NDQ_005720

answers: radiocarbon dating,

text: Fossils of Teratophoneus were first found in the Kaiparowits Formation of southern Utah. Later, fossils from the same formation were discovered and identified as the genus. Argon-argon radiometric dating indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late Cretaceous period. This date means that Teratophoneus lived in the middle of the Campanian stage of the Late Cretaceous. Three different fossils of Teratophoneus have been found. Originally, Teratophoneus was described based on the holotype UMNH VP 16690. More recently, the specimens UMNP VP 16691 and BYU 8120 have been assigned to it.

text: Fossils of Teratophoneus were first found in the Kaiparowits Formation of southern Utah. Later, fossils from the same formation were discovered and identified as the genus.

text: Argon-argon radiometric dating

text: indicates that the Kaiparowits Formation was deposited between 76.1 and 74.0 million years ago, during the Campanian stage of the Late

text: Cretaceous

text: period. This date means that Teratophoneus lived in the middle of the

text: Campanian

text: stage of the

text: Late Cretaceous

text: . Three different fossils of Teratophoneus have been found. Originally, Teratophoneus was described based on the

text: holotype

text: UMNH

text: VP 16690. More recently, the specimens UMNP VP 16691 and BYU 8120 have been assigned to it.

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: Argon-argon

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: Argon-argon radiometric dating

answers: NDQ_005715

answers: How long does it take for carbon-14 to decay to carbon-12?

answers: NDQ_005716

answers: argon radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: argon-argon

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: Argon-argon

answers: NDQ_005712

answers: between 76.1 and 74.0 million years ago,

answers: NDQ_005713

answers: Argon-argon

answers: NDQ_005714

answers: Argon-argon radiometric

answers: NDQ_005715

answers: Argon-argon

answers: NDQ_005716

answers: Argon-argon radiometric dating

answers: NDQ_005717

answers: between 76.1 and 74.0 million years ago,

answers: NDQ_005718

answers: Argon-argon

answers: NDQ_005719

answers: Argon-argon radiometric dating

answers: NDQ_005720

answers: Argon-argon radiometric dating

text: The three naturally-occurring actinide alpha decay chains given below—thorium, uranium/radium (from U-238), and actinium (from U-235)—each ends with its own specific lead isotope (Pb-208, Pb-206, and Pb-207 respectively). All these isotopes are stable and are also present in nature as primordial nuclides, but their excess amounts in comparison with lead-204 (which has only a primordial origin) can be used in the technique of uranium-lead dating to date rocks.

text: The three naturally-occurring actinide alpha decay chains given below—thorium, uranium/radium (from U-238), and actinium (from U-235)—each ends with its own specific lead isotope (Pb-208, Pb-206, and Pb-207 respectively). All these isotopes are stable and are also present in nature as

text: primordial nuclide

text: s, but their excess amounts in comparison with lead-204 (which has only a primordial origin) can be used in the technique of

text: uranium-lead dating

text: to date rocks.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium/radium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: Pb-208

answers: NDQ_005717

answers: Pb-208, Pb-206, and Pb-207 respectively

answers: NDQ_005718

answers: has only a primordial origin

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead dating

answers: NDQ_005712

answers: uranium-lead dating to date rocks.

answers: NDQ_005713

answers: uranium-lead dating

answers: NDQ_005714

answers: uranium-lead dating to date rocks.

answers: NDQ_005715

answers: lead-204

answers: NDQ_005716

answers: date rocks.

answers: NDQ_005717

answers: lead-204

answers: NDQ_005718

answers: lead-204 (which has only a primordial origin)

answers: NDQ_005719

answers: rocks.

answers: NDQ_005720

answers: uranium-lead dating to date rocks.

text: Initial attempts at radiometric dating of the Driftwood Creek beds were unsuccessful, however a volcanic ash exposed in the lake shale beds was radiometrically dated at 51.77 ± 0.34 million years ago.

text: Initial attempts at

text: radiometric dating

text: of the Driftwood Creek beds were unsuccessful, however a volcanic ash exposed in the lake shale beds was

text: radiometrically dated

text: at 51.77 ± 0.34 million years ago.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: radiometric dating works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: failed

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 51.77 <unk> 0.34 million years ago.

answers: NDQ_005712

answers: 51.77 <unk> 0.34 million years ago.

answers: NDQ_005713

answers: 51.77 <unk> 0.34 million years ago.

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: 51.77

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 51.77 <unk> 0.34 million years ago.

answers: NDQ_005718

answers: unsuccessful,

answers: NDQ_005719

answers: 51.77 <unk> 0.34 million years ago.

answers: NDQ_005720

answers: 51.77 <unk> 0.34 million years ago.

text: Garniss H. Curtis, (born May 27, 1919 – died December 19, 2012) was a professor emeritus of geology at the University of California, Berkeley, geochronologist, volcanologist, geophysicist, and founder of the Berkeley Geochronology Center.  In 1960, Curtis and fellow UC Berkeley geophysicist Jack Evernden used potassium-argon dating methods developed by UC Berkeley physicist John Reynolds on minerals found in tephra deposits collected by Evernden to date Mary Leakey's 1959 Olduvai Gorge Bed I hominin Zinjanthropus (Paranthropus boisei) to 1.89 to 1.57 Mya.  The great age of the fossil hominid and associated stone tools in the bed pushed back the then accepted age of the Pleistocene another million years, causing a stir in the geology community. The dating of these fossil finds is considered a starting point for the collaboration of paleoanthropology and geochronology.

text: Garniss H. Curtis, (born May 27, 1919 – died December 19, 2012) was a

text: professor emeritus

text: of

text: geology

text: at the

text: University of California, Berkeley

text: geochronologist

text: volcanologist

text: geophysicist

text: , and founder of the

text: Berkeley Geochronology Center

text: .  In 1960, Curtis and fellow UC Berkeley geophysicist

text: Jack Evernden

text: used

text: potassium-argon dating

text: methods developed by UC Berkeley

text: physicist

text: John Reynolds

text: on minerals found in

text: tephra

text: deposits collected by Evernden to date

text: Mary Leakey

text: 's 1959

text: Olduvai Gorge

text: Bed I

text: hominin

text: Zinjanthropus (

text: Paranthropus boisei

text: ) to 1.89 to 1.57

text: Mya

text: .  The great age of the fossil

text: hominid

text: and associated stone tools in the bed pushed back the then accepted age of the

text: Pleistocene

text: another million years, causing a stir in the geology community. The dating of these fossil finds is considered a starting point for the collaboration of

text: paleoanthropology

text: and

text: geochronology

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-argon dating methods

answers: NDQ_005715

answers: potassium-argon dating

answers: NDQ_005716

answers: carbon dating measures when the organism died

answers: NDQ_005717

answers: minerals found in tephra deposits collected by Evernden

answers: NDQ_005718

answers: potassium-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 1.89 to 1.57 Mya.

answers: NDQ_005713

answers: potassium-argon

answers: NDQ_005714

answers: paleoanthropology and geochronology.

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: minerals found in tephra deposits

answers: NDQ_005718

answers: age of the Pleistocene another million years,

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: potassium-argon

text: The maximum published age of 149 years was determined via radiometric dating of trace isotopes found in an orange roughy's otolith (ear bone). Similarly, counting by the growth rings of orange roughy otoliths has given a maximum age of 125 to 156 years. The validity of these results is questioned by commercial fishers as some state the former method is controversial and the latter method is known to underestimate age in older specimens. The issue has yet to be resolved definitively, but carries important implications relating to the orange roughy's conservation status.

text: The maximum published age of 149 years was determined via

text: radiometric dating

text: of trace

text: isotope

text: s found in an orange roughy's

text: otolith

text: (ear bone). Similarly, counting by the

text: growth ring

text: s of orange roughy otoliths has given a maximum age of 125 to 156 years. The validity of these results is questioned by commercial fishers as some state the former method is controversial and the latter method is known to underestimate age in older specimens. The issue has yet to be resolved definitively, but carries important implications relating to the orange roughy's

text: conservation status

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: trace isotopes

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating of trace isotopes

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric

answers: NDQ_005717

answers: radiometric dating of trace isotopes

answers: NDQ_005718

answers: the latter method is known to underestimate age in older specimens

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: trace isotopes

answers: NDQ_005712

answers: 125 to 156 years.

answers: NDQ_005713

answers: trace isotopes

answers: NDQ_005714

answers: known to underestimate age in older specimens.

answers: NDQ_005715

answers: 125 to 156 years.

answers: NDQ_005716

answers: growth rings

answers: NDQ_005717

answers: trace isotopes

answers: NDQ_005718

answers: underestimate age in older specimens.

answers: NDQ_005719

answers: counting by the growth rings

answers: NDQ_005720

answers: 125 to 156 years.

text: The above calculations make several assumptions, such as that the level of  in the atmosphere has remained constant over time. In fact, the level of  in the atmosphere has varied significantly and as a result the values provided by the equation above have to be corrected by using data from other sources.  This is done by calibration curves, which convert a measurement of  in a sample into an estimated calendar age.  The calculations involve several steps and include an intermediate value called the "radiocarbon age", which is the age in "radiocarbon years" of the sample: an age quoted in radiocarbon years means that no calibration curve has been used − the calculations for radiocarbon years assume that the / ratio has not changed over time.  Calculating radiocarbon ages also requires the value of the half-life for , which for more than a decade after Libby's initial work was thought to be 5,568 years.  This was revised in the early 1960s to 5,730 years, which meant that many calculated dates in papers published prior to this were incorrect (the error in the half-life is about 3%).  For consistency with these early papers, and to avoid the risk of a double correction for the incorrect half-life, radiocarbon ages are still calculated using the incorrect half-life value.  A correction for the half-life is incorporated into calibration curves, so even though radiocarbon ages are calculated using a half-life value that is known to be incorrect, the final reported calibrated date, in calendar years, is accurate.  When a date is quoted, the reader should be aware that if it is an uncalibrated date (a term used for dates given in radiocarbon years) it may differ substantially from the best estimate of the actual calendar date, both because it uses the wrong value for the half-life of , and because no correction (calibration) has been applied for the historical variation of  in the atmosphere over time.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon ages are still calculated using the incorrect half-life value

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: half-life

answers: NDQ_005717

answers: radiocarbon ages are still calculated using the incorrect half-life value

answers: NDQ_005718

answers: it may differ substantially from the best estimate of the actual calendar date

answers: NDQ_005719

answers: radiocarbon ages are calculated using the incorrect half-life value

answers: NDQ_005720

answers: radiocarbon ages

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon years

answers: NDQ_005714

answers: radiocarbon ages are still calculated using the incorrect half-life value.

answers: NDQ_005715

answers: 5,568 years.

answers: NDQ_005716

answers: half-life,

answers: NDQ_005717

answers: radiocarbon ages are still calculated using the incorrect half-life value.

answers: NDQ_005718

answers: radiocarbon ages are still calculated using the incorrect half-life value.

answers: NDQ_005719

answers: 3%).

answers: NDQ_005720

answers: (the error in the half-life is about 3%).

text: Cordón del Azufre is a small, inactive complex volcano located in the Central Andes, at the border of Argentina and Chile. The centre contains a series of craters and lava flows covering a surface area of . A western component with four craters aligned in a north–south direction on a  ridge forms the oldest part. The eastern component is formed by lava flows and craters in Argentina, and the youngest part la Moyra volcano in the western component generated a lava flow that advanced  westwards. Weakly porphyritic Andesite and dacite form the rocks of the volcano. No activity, including fumarolic activity, has been recorded at Cordón del Azufre, but the appearance (dark and pristine) and radiometric age (0.3 ± 0.3 mya K-Ar on the most recent flow) of the lava flows suggest a recent age.

text: Cordón del Azufre is a small, inactive

text: complex volcano

text: located in the Central

text: Andes

text: , at the border of

text: Argentina

text: and

text: Chile

text: . The centre contains a series of

text: crater

text: s and

text: lava flow

text: s covering a surface area of . A western component with four craters aligned in a north–south direction on a

text: ridge

text: forms the oldest part. The eastern component is formed by lava flows and craters in Argentina, and the youngest part la Moyra volcano in the western component generated a lava flow that advanced  westwards. Weakly

text: porphyritic

text: Andesite

text: and

text: dacite

text: form the rocks of the volcano. No activity, including

text: fumarolic

text: activity, has been recorded at Cordón del Azufre, but the appearance (dark and pristine) and

text: radiometric age

text: (0.3 ± 0.3 mya

text: K-Ar

text: on the most recent flow) of the lava flows suggest a recent age.

answers: NDQ_005711

answers: radiometric age

answers: NDQ_005712

answers: lava flows suggest a recent age

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: How old is Cordón del Azufre?

answers: NDQ_005716

answers: radiometric age

answers: NDQ_005717

answers: 0.3  0.3 mya K-Ar on the most recent flow

answers: NDQ_005718

answers: 0.3  0.3 mya

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: (0.3 <unk> 0.3 mya K-Ar

answers: NDQ_005712

answers: (0.3 <unk> 0.3 mya K-Ar

answers: NDQ_005713

answers: radiometric age

answers: NDQ_005714

answers: radiometric age

answers: NDQ_005715

answers: Cordón del Azufre

answers: NDQ_005716

answers: radiometric age

answers: NDQ_005717

answers: (0.3 <unk> 0.3 mya

answers: NDQ_005718

answers: No activity,

answers: NDQ_005719

answers: recent age.

answers: NDQ_005720

answers: radiometric age

text: Stonebergia has been identified from a location, the type locality, at the "One mile Creek" exposure of the Allenby Formation near Princeton, British Columbia. The Allenby Formation is currently considered to be Early Eocene in age, based on potassium–argon radiometric dating of plagioclase and biotite crystals.  The Allenby formation sediments are interpreted as preserved river lake and wetlands systems, with a surrounding mountain environment.

text: Stonebergia has been identified from a location, the

text: type locality

text: , at the "One mile Creek" exposure of the

text: Allenby Formation

text: near

text: Princeton, British Columbia

text: . The Allenby Formation is currently considered to be Early Eocene in age, based on

text: potassium–argon

text: radiometric dating

text: of

text: plagioclase

text: and

text: biotite

text: crystals.  The Allenby formation sediments are interpreted as preserved river lake and wetlands systems, with a surrounding mountain environment.

answers: NDQ_005711

answers: potassium–argon

answers: NDQ_005712

answers: potassium–argon

answers: NDQ_005713

answers: Yes

answers: NDQ_005714

answers: potassium–argon radiometric dating

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: potassium–argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium–argon

answers: NDQ_005712

answers: potassium–argon

answers: NDQ_005713

answers: potassium–argon

answers: NDQ_005714

answers: potassium–argon radiometric dating

answers: NDQ_005715

answers: potassium–argon

answers: NDQ_005716

answers: potassium–argon radiometric dating

answers: NDQ_005717

answers: The Allenby Formation is currently considered to be Early Eocene

answers: NDQ_005718

answers: potassium–argon

answers: NDQ_005719

answers: potassium–argon radiometric dating

answers: NDQ_005720

answers: potassium–argon radiometric dating

text: Helium dating may refer to the traditional uranium-thorium dating or uranium-thorium/helium dating.

text: Helium dating may refer to the traditional

text: uranium-thorium dating

text: or uranium-thorium/helium dating.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium-thorium

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: helium decay

answers: NDQ_005717

answers: uranium-thorium

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Helium dating

answers: NDQ_005712

answers: uranium-thorium

answers: NDQ_005713

answers: Helium dating

answers: NDQ_005714

answers: Helium dating

answers: NDQ_005715

answers: Helium dating

answers: NDQ_005716

answers: Helium dating

answers: NDQ_005717

answers: Helium dating

answers: NDQ_005718

answers: Helium dating

answers: NDQ_005719

answers: Helium dating

answers: NDQ_005720

answers: Helium dating

text: Between 1997 and 2005, a team of scientists at the Institute for Creation Research conducted an eight-year research project entitled RATE (Radioisotopes and the Age of The Earth) to assess the validity and accuracy of radiometric dating techniques. While they concluded that there was overwhelming evidence for over 500 million years' worth of radioactive decay, they claimed to have found other scientific evidence to prove a young earth. They therefore proposed that nuclear decay rates were accelerated by a factor of one billion during the Creation week and at the time of the Flood. However, when subjected to independent scrutiny by non-affiliated experts, their analyses were shown to be flawed.

text: Between 1997 and 2005, a team of scientists at the

text: Institute for Creation Research

text: conducted an eight-year research project entitled

text: RATE

text: (Radioisotopes and the Age of The Earth) to assess the validity and accuracy of radiometric dating techniques. While they concluded that there was overwhelming evidence for over 500 million years' worth of radioactive decay, they claimed to have found other scientific evidence to prove a young earth. They therefore proposed that nuclear decay rates were accelerated by a factor of one billion during the Creation week and at the time of the Flood. However, when subjected to independent scrutiny by non-affiliated experts, their analyses were shown to be flawed.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: over 500 million years

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radioactive decay

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: radioactive decay

answers: NDQ_005718

answers: their analyses were shown to be flawed

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactive decay,

answers: NDQ_005712

answers: over 500 million years' worth of radioactive decay,

answers: NDQ_005713

answers: (Radioisotopes and the Age of The Earth)

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: 500 million years' worth of radioactive decay,

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: nuclear decay rates were accelerated by a factor of one billion

answers: NDQ_005718

answers: when subjected to independent scrutiny by non-affiliated experts,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Over the next thirty years many calibration curves were published using a variety of methods and statistical approaches. These were superseded by the INTCAL series of curves, beginning with INTCAL98, published in 1998, and updated in 2004, 2009, and 2013. The improvements to these curves are based on new data gathered from tree rings, varves, coral, plant macrofossils, speleothems, and foraminifera.  The INTCAL13 data includes separate curves for the northern and southern hemispheres, as they differ systematically because of the hemisphere effect; there is also a separate marine calibration curve. For a set of samples with a known sequence and separation in time such as a sequence of tree rings, the samples' radiocarbon ages form a small subset of the calibration curve. The resulting curve can then be matched to the actual calibration curve by identifying where, in the range suggested by the radiocarbon dates, the wiggles in the calibration curve best match the wiggles in the curve of sample dates. This "wiggle-matching" technique can lead to more precise dating than is possible with individual radiocarbon dates.  Wiggle-matching can be used in places where there is a plateau on the calibration curve, and hence can provide a much more accurate date than the intercept or probability methods are able to produce.  The technique is not restricted to tree rings; for example, a stratified tephra sequence in New Zealand, known to predate human colonization of the islands, has been dated to 1314 AD ± 12 years by wiggle-matching. The wiggles also mean that reading a date from a calibration curve can give more than one answer: this occurs when the curve wiggles up and down enough that the radiocarbon age intercepts the curve in more than one place, which may lead to a radiocarbon result being reported as two separate age ranges, corresponding to the two parts of the curve that the radiocarbon age intercepted.

text: Over the next thirty years many calibration curves were published using a variety of methods and statistical approaches. These were superseded by the INTCAL series of curves, beginning with INTCAL98, published in 1998, and updated in 2004, 2009, and 2013. The improvements to these curves are based on new data gathered from tree rings,

text: varve

text: s,

text: coral

text: , plant

text: macrofossil

text: s,

text: speleothems

text: , and

text: foraminifera

text: .  The INTCAL13 data includes separate curves for the northern and southern hemispheres, as they differ systematically because of the hemisphere effect; there is also a separate marine calibration curve. For a set of samples with a known sequence and separation in time such as a sequence of tree rings, the samples' radiocarbon ages form a small subset of the calibration curve. The resulting curve can then be matched to the actual calibration curve by identifying where, in the range suggested by the radiocarbon dates, the wiggles in the calibration curve best match the wiggles in the curve of sample dates. This "wiggle-matching" technique can lead to more precise dating than is possible with individual radiocarbon dates.  Wiggle-matching can be used in places where there is a plateau on the calibration curve, and hence can provide a much more accurate date than the intercept or probability methods are able to produce.  The technique is not restricted to tree rings; for example, a stratified

text: tephra

text: sequence in New Zealand, known to predate human colonization of the islands, has been dated to 1314 AD ± 12 years by wiggle-matching. The wiggles also mean that reading a date from a calibration curve can give more than one answer: this occurs when the curve wiggles up and down enough that the radiocarbon age intercepts the curve in more than one place, which may lead to a radiocarbon result being reported as two separate age ranges, corresponding to the two parts of the curve that the radiocarbon age intercepted.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating only works for materials of these ages because

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains and artifacts

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: wiggle-matching

answers: NDQ_005717

answers: This "wiggle-matching" technique can lead to more precise dating than is possible with individual radiocarbon dates.

answers: NDQ_005718

answers: reading a date from a calibration curve can give more than one answer

answers: NDQ_005719

answers: Wiggle-matching

answers: NDQ_005720

answers: radiocarbon ages

answers: NDQ_005711

answers: the radiocarbon age intercepts the curve in more than one place,

answers: NDQ_005712

answers: known sequence and separation in time

answers: NDQ_005713

answers: "wiggle-matching"

answers: NDQ_005714

answers: "wiggle-matching" technique can lead to more precise dating

answers: NDQ_005715

answers: "wiggle-matching"

answers: NDQ_005716

answers: individual radiocarbon dates.

answers: NDQ_005717

answers: "wiggle-matching"

answers: NDQ_005718

answers: intercept or probability methods

answers: NDQ_005719

answers: wiggles in the curve of sample dates.

answers: NDQ_005720

answers: "wiggle-matching"

text: Absolute dates, subject to a statistical uncertainty, are determined through radiometric dating using isotope ratios such as Ar/Ar dating, which can be used to identify the date of solidifying basalt. In the CRBG deposits Ar, which is produced by K decay, only accumulates after the melt solidifies.

text: Absolute dates, subject to a statistical uncertainty, are determined through

text: radiometric dating

text: using isotope ratios such as

text: Ar/Ar

text: dating, which can be used to identify the date of solidifying basalt. In the CRBG deposits Ar, which is produced by K decay, only accumulates after the melt solidifies.

answers: NDQ_005711

answers: isotope

answers: NDQ_005712

answers: solidifying basalt

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays

answers: NDQ_005715

answers: NDQ_005716

answers: Ar decay

answers: NDQ_005717

answers: K decay, only accumulates after the melt solidifies

answers: NDQ_005718

answers: statistical uncertainty

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: isotope ratios

answers: NDQ_005712

answers: Absolute dates, subject to a statistical uncertainty,

answers: NDQ_005713

answers: isotope ratios

answers: NDQ_005714

answers: Absolute dates, subject to a statistical uncertainty,

answers: NDQ_005715

answers: Ar/Ar dating,

answers: NDQ_005716

answers: K decay, only accumulates after the melt solidifies.

answers: NDQ_005717

answers: Ar, which is produced by K decay,

answers: NDQ_005718

answers: statistical uncertainty,

answers: NDQ_005719

answers: Ar/Ar dating,

answers: NDQ_005720

answers: Ar/Ar dating,

text: Thermochronology is the study of the thermal evolution of a region of a planet. Thermochronologists use radiometric dating along with the closure temperatures that represent the temperature of the mineral being studied at the time given by the date recorded, to understand the thermal history of a specific rock, mineral, or geologic unit. It is a subfield within geology, and is closely associated with geochronology.

text: Thermochronology is the study of the thermal evolution of a region of a planet. Thermochronologists use

text: radiometric dating

text: along with the

text: closure temperature

text: s that represent the temperature of the mineral being studied at the time given by the date recorded, to understand the thermal history of a specific rock, mineral, or geologic unit. It is a subfield within

text: geology

text: , and is closely associated with

text: geochronology

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: thermochronology

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: temperature of the mineral being studied at the time given by the date recorded

answers: NDQ_005718

answers: thermochronology

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: date recorded,

answers: NDQ_005712

answers: thermal history of a specific rock, mineral, or geologic unit.

answers: NDQ_005713

answers: Thermochronologists use radiometric dating

answers: NDQ_005714

answers: to understand the thermal history

answers: NDQ_005715

answers: Thermochronology

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: closure temperatures

answers: NDQ_005718

answers: date recorded,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: It is similar to El Rojo Norte  farther north. A mafic andesite lava flow was erupted from the  high cone that also features red scoria. Ages obtained by potassium-argon dating are 2.93±0.13, 3.4±0.4 and 3.23±0.12 mya.

text: It is similar to

text: El Rojo Norte

text: farther north. A

text: mafic

text: andesite lava flow was erupted from the  high cone that also features red scoria. Ages obtained by

text: potassium-argon dating

text: are 2.93±0.13, 3.4±0.4 and 3.23±0.12

text: mya

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon is a noble gas

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dating is not reliable

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 2.93 0.13

answers: NDQ_005718

answers: potassium-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: 2.93<unk>0.13,

answers: NDQ_005716

answers: Ages obtained by potassium-argon

answers: NDQ_005717

answers: Ages

answers: NDQ_005718

answers: Ages

answers: NDQ_005719

answers: 3.23<unk>0.12 mya.

answers: NDQ_005720

answers: potassium-argon

text: Relative dates for both categories have been established using radiocarbon dates from sites with similar assemblages from Colorado, Wyoming, Kansas, Montana, and elsewhere.  These dates are 9350 – 7900 radiocarbon years for Jimmy Allen (Pitblado 2003) and 11,000 radiocarbon years for Goshen/Plainview (Frison 1991).

text: Relative dates for both categories have been established using radiocarbon dates from sites with similar assemblages from

text: Colorado

text: Wyoming

text: Kansas

text: Montana

text: , and elsewhere.  These dates are 9350 – 7900 radiocarbon years for Jimmy Allen (Pitblado 2003) and 11,000 radiocarbon years for Goshen/Plainview (Frison 1991).

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon dating is used for dating human remains

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon years

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dates from sites with similar assemblages

answers: NDQ_005715

answers: 9350 – 7900

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: 9350 – 7900 radiocarbon years for Jimmy Allen

answers: NDQ_005718

answers: Relative dates

answers: NDQ_005719

answers: Relative dates for both categories have been established using radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: Geologists have attempted to date the Cardenas Basalt for many years. On the basis of other geologic criteria, geologists have found that the dates, which range from 700 to 1,000 million years ago, obtained for the age of the Cardenas Basalt and upper age of the Unkar Group were too young and something was clearly perturbing the dating systematics. The current interpretation is that the deposition of the overlying Chuar Group in a marine setting disrupted the potassium-argon (K-Ar) radiometric system. Apparently, fluids associated with the deposition of the Chuar Group have altered the older Cardenas Basalt, partially degraded the minerals, and therefore disrupted the K-Ar systematics. Using newer dating techniques and approaches not available to earlier geologists, the Cardenas Basalt and intrusive sills have been re-dated. New data acquired using newer dating techniques and approaches, indicate that the Cardenas Basalt erupted about 1,104 million years ago. This date marks the end of Unkar time.

text: Geologist

text: s have attempted to date the Cardenas Basalt for many years. On the basis of other geologic criteria, geologists have found that the dates, which range from 700 to 1,000 million years ago, obtained for the age of the Cardenas Basalt and upper age of the Unkar Group were too young and something was clearly perturbing the dating systematics. The current interpretation is that the deposition of the overlying Chuar Group in a marine setting disrupted the potassium-argon (K-Ar) radiometric system. Apparently, fluids associated with the deposition of the Chuar Group have altered the older Cardenas Basalt, partially degraded the minerals, and therefore disrupted the K-Ar systematics. Using newer dating techniques and approaches not available to earlier geologists, the Cardenas Basalt and intrusive sills have been re-dated. New data acquired using newer dating techniques and approaches, indicate that the Cardenas Basalt erupted about 1,104 million years ago. This date marks the end of

text: Unkar

text: time.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon (K-Ar)

answers: NDQ_005715

answers: K-Ar

answers: NDQ_005716

answers: unkar time

answers: NDQ_005717

answers: (K-Ar) radiometric system

answers: NDQ_005718

answers: too young

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 700 to 1,000 million years ago,

answers: NDQ_005713

answers: potassium-argon (K-Ar) radiometric system.

answers: NDQ_005714

answers: (K-Ar) radiometric system.

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: (K-Ar) radiometric system.

answers: NDQ_005717

answers: (K-Ar) radiometric system.

answers: NDQ_005718

answers: too young

answers: NDQ_005719

answers: potassium-argon (K-Ar) radiometric system.

answers: NDQ_005720

answers: 700 to 1,000 million years ago,

text: Many pages contain substantial drawings or charts which are colored with paint. Based on modern analysis using polarized light microscopy (PLM), it has been determined that a quill pen and iron gall ink were used for the text and figure outlines; the colored paint was applied (somewhat crudely) to the figures, possibly at a later date. The ink of the drawings, text and page and quire numbers had similar microscopic characteristics. Energy-dispersive X-ray spectroscopy (EDS) performed in 2009 revealed that the inks contained major amounts of iron, sulfur, potassium, calcium and carbon and trace amounts of copper and occasionally zinc. EDS did not show the presence of lead, while X-ray Diffraction (XRD) identified potassium lead oxide, potassium hydrogen sulphate and syngenite in one of the samples tested. The similarity between the drawing inks and text inks suggested a contemporaneous origin.

text: Many pages contain substantial drawings or charts which are colored with paint. Based on modern analysis using

text: polarized light microscopy

text: (PLM), it has been determined that a

text: quill pen

text: and

text: iron gall ink

text: were used for the text and figure outlines; the colored paint was applied (somewhat crudely) to the figures, possibly at a later date. The ink of the drawings, text and page and quire numbers had similar microscopic characteristics.

text: Energy-dispersive X-ray spectroscopy

text: (EDS) performed in 2009 revealed that the inks contained major amounts of iron, sulfur, potassium, calcium and carbon and

text: trace amounts

text: of copper and occasionally zinc. EDS did not show the presence of lead, while

text: X-ray Diffraction

text: (XRD) identified potassium

text: lead oxide

text: , potassium hydrogen sulphate and

text: syngenite

text: in one of the samples tested. The similarity between the drawing inks and text inks suggested a contemporaneous origin.

answers: NDQ_005711

answers: X-ray Diffraction

answers: NDQ_005712

answers: X-ray Diffraction (XRD)

answers: NDQ_005713

answers: NDQ_005714

answers: energy-dispersive X-ray spectroscopy

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating measures when the organism died because only then does

answers: NDQ_005717

answers: Energy-dispersive X-ray spectroscopy (EDS)

answers: NDQ_005718

answers: the presence of lead

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: Energy-dispersive X-ray spectroscopy

answers: NDQ_005712

answers: contemporaneous origin.

answers: NDQ_005713

answers: polarized light microscopy

answers: NDQ_005714

answers: Energy-dispersive X-ray spectroscopy

answers: NDQ_005715

answers: lead,

answers: NDQ_005716

answers: carbon

answers: NDQ_005717

answers: EDS did not show the presence of lead,

answers: NDQ_005718

answers: EDS did not show the presence of lead,

answers: NDQ_005719

answers: EDS did not show the presence of lead,

answers: NDQ_005720

answers: X-ray Diffraction (XRD) identified potassium lead oxide,

text: Ceratomyrmex is known from a total of four adult fossils. The holotype is specimen number "NIGP164022" of the Nanjing Institute of Geology and Paleontology; the adult specimen "IGR.BU-002" of the University of Rennes is designated as paratype.  The two additional specimens described but not designated as paratypes were residing in the private collection of Sieghard Ellenberger, Germany.  The described specimens are of worker caste adults which have been preserved as inclusions in transparent chunks of Burmese amber.  The amber specimens were recovered from deposits in Kachin State, in Myanmar.  Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the Aptian – Cenomanian boundary, in the earliest Cenomanian.

text: Ceratomyrmex is known from a total of four adult fossils. The

text: holotype

text: is specimen number "NIGP164022" of the Nanjing Institute of Geology and Paleontology; the adult specimen "IGR.BU-002" of the University of Rennes is designated as paratype.  The two additional specimens described but not designated as paratypes were residing in the private collection of Sieghard Ellenberger, Germany.  The described specimens are of

text: worker caste

text: adults which have been preserved as

text: inclusions

text: in transparent chunks of

text: Burmese amber

text: .  The

text: amber

text: specimens were recovered from deposits in

text: Kachin State

text: , in Myanmar.  Burmese amber has been

text: radiometrically dated

text: using

text: U

text: Pb

text: isotopes, yielding an age of approximately 98.79 ± 0.62  million years old, close to the

text: Aptian

text: Cenomanian

text: boundary, in the earliest Cenomanian.

answers: NDQ_005711

answers: using U-Pb isotopes

answers: NDQ_005712

answers: U-Pb

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: U-Pb isotopes

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: radiometrically dated using U-Pb isotopes

answers: NDQ_005718

answers: U-Pb isotopes

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: U-Pb isotopes,

answers: NDQ_005712

answers: U-Pb isotopes,

answers: NDQ_005713

answers: U-Pb isotopes,

answers: NDQ_005714

answers: U-Pb isotopes,

answers: NDQ_005715

answers: Ceratomyrmex

answers: NDQ_005716

answers: radiometrically dated using U-Pb isotopes,

answers: NDQ_005717

answers: U-Pb isotopes,

answers: NDQ_005718

answers: U-Pb isotopes,

answers: NDQ_005719

answers: U-Pb isotopes,

answers: NDQ_005720

answers: U-Pb isotopes,

text: An analysis of early Chinese mathematics has demonstrated its unique development compared to other parts of the world, leading scholars to assume an entirely independent development. The oldest extant mathematical text from China is the Chou Pei Suan Ching, variously dated to between 1200 BC and 100 BC, though a date of about 300 BC appears reasonable. However, the Tsinghua Bamboo Slips, containing the earliest known decimal multiplication table (although ancient Babylonians had ones with a base of 60), is dated around 305 BC and is perhaps the oldest surviving mathematical text of China.

text: An analysis of early Chinese mathematics has demonstrated its unique development compared to other parts of the world, leading scholars to assume an entirely independent development. The oldest extant mathematical text from China is the

text: Chou Pei Suan Ching

text: , variously dated to between 1200 BC and 100 BC, though a date of about 300 BC appears reasonable. However, the

text: Tsinghua Bamboo Slips

text: , containing the earliest known

text: decimal

text: multiplication table

text: (although ancient Babylonians had ones with a base of 60), is dated around 305 BC and is perhaps the oldest surviving mathematical text of China.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Chou Pei Suan Ching

answers: NDQ_005713

answers: unanswerable

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Chou Pei Suan Ching

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 1200 BC and 100 BC,

answers: NDQ_005712

answers: 1200 BC and 100 BC,

answers: NDQ_005713

answers: 1200 BC and 100 BC,

answers: NDQ_005714

answers: independent development.

answers: NDQ_005715

answers: 1200 BC and 100 BC,

answers: NDQ_005716

answers: surviving

answers: NDQ_005717

answers: 305 BC

answers: NDQ_005718

answers: ancient Babylonians had ones with a base of 60),

answers: NDQ_005719

answers: 1200 BC and 100 BC,

answers: NDQ_005720

answers: 1200 BC and 100 BC,

text: The Ringing Rocks Pluton is one of several bimodal vent complexes that are located within a 20 km belt east of the main Butte Pluton. Radiometric dating and cross-cutting relationships place most of these intrusions as post-Elkhorn Mountains Volcanics and pre-Butte Pluton. Similar intrusions can be found in the Rader Creek Pluton.

text: The Ringing Rocks Pluton is one of several bimodal vent complexes that are located within a 20 km belt east of the main Butte Pluton. Radiometric dating and cross-cutting relationships place most of these intrusions as post-Elkhorn Mountains Volcanics and pre-Butte Pluton. Similar intrusions can be found in the Rader Creek Pluton.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: pre-Butte Pluton

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Radiometric dating

answers: NDQ_005718

answers: cross-cutting relationships

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: cross-cutting relationships

answers: NDQ_005712

answers: post-Elkhorn Mountains Volcanics

answers: NDQ_005713

answers: Radiometric dating

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: The Ringing Rocks Pluton

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: Radiometric dating and cross-cutting relationships

answers: NDQ_005718

answers: cross-cutting relationships

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: While some of what happens on a date is guided by an understanding of basic, unspoken rules, there is considerable room to experiment, and there are numerous sources of advice available. Sources of advice include magazine articles, self-help books, dating coaches, friends, and many other sources. And the advice given can pertain to all facets of dating, including such aspects as where to go, what to say, what not to say, what to wear, how to end a date, how to flirt, and differing approaches regarding first dates versus subsequent dates. In addition, advice can apply to periods before a date, such as how to meet prospective partners, as well as after a date, such as how to break off a relationship.

text: While some of what happens on a date is guided by an understanding of basic, unspoken rules, there is considerable room to experiment, and there are numerous sources of advice available. Sources of advice include magazine articles, self-help books, dating coaches, friends, and many other sources. And the advice given can pertain to all facets of dating, including such aspects as where to go, what to say, what not to say, what to wear, how to end a date, how to flirt, and differing approaches regarding first dates versus subsequent dates. In addition, advice can apply to periods before a date, such as how to meet prospective partners, as well as after a date, such as how to break off a relationship.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: how to end a date

answers: NDQ_005718

answers: unspoken rules

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: sources of advice

answers: NDQ_005712

answers: first dates versus subsequent dates.

answers: NDQ_005713

answers: dating coaches,

answers: NDQ_005714

answers: unspoken rules,

answers: NDQ_005715

answers: what to say, what not to say,

answers: NDQ_005716

answers: unspoken rules,

answers: NDQ_005717

answers: what to say, what not to say,

answers: NDQ_005718

answers: unspoken rules,

answers: NDQ_005719

answers: first dates versus subsequent dates.

answers: NDQ_005720

answers: what to say, what not to say,

text: The pass was created when a huge mountain slide (actually the collapse of an entire mountain, with an estimated volume of 1 km; the third-largest mountain slide ever in the eastern Alps) filled part of the valley to a height of 300–400 meters, distributing its boulders up to 16 km away. While it was initially believed that this had happened at least 12,000 years B.P. as a consequence of the strong temperature increase and intense run-off after the end of the last deglaciation, pollen analysis performed as early as 1940 had already indicated an age of not much more than 4,000 years (i.e., an event date around 2000 BC), an estimate that was essentially confirmed by radiocarbon dating in the 1960s. Using uranium-thorium dating, scientists from Innsbruck University who published their data in 2007 dated the event to 4,150 +/- 100 years B.P., i.e., to the 22nd century BC which corresponds to the latest stages of the Alpine neolithic period.

text: The pass was created when a huge mountain slide (actually the collapse of an entire mountain, with an estimated volume of 1 km; the third-largest mountain slide ever in the eastern Alps) filled part of the valley to a height of 300–400 meters, distributing its boulders up to 16 km away. While it was initially believed that this had happened at least 12,000 years B.P. as a consequence of the strong temperature increase and intense run-off after the end of the last deglaciation,

text: pollen analysis

text: performed as early as 1940 had already indicated an age of not much more than 4,000 years (i.e., an event date around 2000 BC), an estimate that was essentially confirmed by

text: radiocarbon dating

text: in the 1960s. Using

text: uranium-thorium dating

text: , scientists from

text: Innsbruck University

text: who published their data in 2007 dated the event to 4,150 +/- 100 years B.P., i.e., to the 22nd century BC which corresponds to the latest stages of the Alpine

text: neolithic

text: period.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: uranium-thorium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: uranium-thorium

answers: NDQ_005718

answers: radiocarbon dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: 4,000 years

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 4,150 +/- 100 years B.P.,

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: uranium-thorium

text: A road rises to Veste Oberhaus on the Ilz side. On foot, the castle can be reached via the 200 steps of the Oberhausleiten-Stiege stairway from the Schanzlbrücke Danube bridge. The main gate, the Ravelintor, bears the arms of Cardinal Johann Philipp von Lamberg and was built in 1703. This leads to the Kronwerke, a Baroque bailey constructed in 1674–1740, and a second defensive area dating mostly to the 16th century. From this middle defensive ring, the Burgstraße leads past the main watchtower (built around 1350) and across a drawbridge through a tower built in 1433 to the main fortress. The gate tower at this point bears the arms of Prince Bishop Leonhard von Laiming dated 1440. The buildings encircling the outer courtyard are 16th-century. The church of St. George in the inner courtyard has early and high Gothic frescoes and predates the fortress; it was renovated in Baroque style. The building erected by Christoph von Schachner in 1499–1503 with the highly visible coat of arms and date of 1499 on its facade contains a ceremonial Rittersaal (knights' hall) on the upper floor; this is connected by an open arcade to the dirnitz and princely suite, which date to the 14th–17th centuries. A cannon battery is housed on the lower story under the Rittersaal.

text: A road rises to Veste Oberhaus on the Ilz side. On foot, the castle can be reached via the 200 steps of the Oberhausleiten-Stiege stairway from the Schanzlbrücke Danube bridge. The main gate, the Ravelintor, bears the arms of Cardinal Johann Philipp von Lamberg and was built in 1703. This leads to the Kronwerke, a

text: Baroque

text: bailey constructed in 1674–1740, and a second defensive area dating mostly to the 16th century. From this middle defensive ring, the Burgstraße leads past the main watchtower (built around 1350) and across a drawbridge through a tower built in 1433 to the main fortress. The gate tower at this point bears the arms of Prince Bishop Leonhard von Laiming dated 1440. The buildings encircling the outer courtyard are 16th-century. The church of St. George in the inner courtyard has early and high

text: Gothic

text: frescoes and predates the fortress; it was renovated in Baroque style. The building erected by Christoph von Schachner in 1499–1503 with the highly visible coat of arms and date of 1499 on its facade contains a ceremonial Rittersaal (knights' hall) on the upper floor; this is connected by an open arcade to the

text: dirnitz

text: and princely suite, which date to the 14th–17th centuries. A cannon battery is housed on the lower story under the Rittersaal.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 14th–17th centuries

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 1433 to the main fortress

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: None of the above choices are available

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: 16th century.

answers: NDQ_005712

answers: 14th–17th centuries.

answers: NDQ_005713

answers: 1703.

answers: NDQ_005714

answers: 1703.

answers: NDQ_005715

answers: 1703.

answers: NDQ_005716

answers: 1440.

answers: NDQ_005717

answers: 1440.

answers: NDQ_005718

answers: highly visible coat of arms and date of 1499

answers: NDQ_005719

answers: 16th century.

answers: NDQ_005720

answers: 1703.

text: There is also contention on the founding dates of many universities. Using the date of acquisition of a papal and royal/imperial charter is inadequate, as the older universities, believing their status and reputations sufficient and indisputable, refused or resisted asking for an official charter for a long time. Some historians trace the founding of a university to the first date when evidence of some kind of teaching was done in that locality, even if only local and limited. Others wait until there is evidence of higher learning, a wide student catchment, the emergence of its masters teaching elsewhere or a more definitive mention of it as a Studium generale.

text: There is also contention on the founding dates of many universities. Using the date of acquisition of a papal and royal/imperial charter is inadequate, as the older universities, believing their status and reputations sufficient and indisputable, refused or resisted asking for an official charter for a long time. Some historians trace the founding of a university to the first date when evidence of some kind of teaching was done in that locality, even if only local and limited. Others wait until there is evidence of higher learning, a wide student catchment, the emergence of its masters teaching elsewhere or a more definitive mention of it as a Studium generale.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: materials of these ages

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Using the date of acquisition of a papal and royal/imperial charter is inadequate

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: evidence of some kind of teaching was done in that locality,

answers: NDQ_005712

answers: date of acquisition of a papal and royal/imperial charter

answers: NDQ_005713

answers: date of acquisition of a papal and royal/imperial charter

answers: NDQ_005714

answers: inadequate,

answers: NDQ_005715

answers: date of acquisition of a papal and royal/imperial charter

answers: NDQ_005716

answers: date of acquisition of a papal and royal/imperial charter

answers: NDQ_005717

answers: evidence of some kind of teaching was done in that locality,

answers: NDQ_005718

answers: date of acquisition of a papal and royal/imperial charter

answers: NDQ_005719

answers: date of acquisition of a papal and royal/imperial charter

answers: NDQ_005720

answers: date of acquisition of a papal and royal/imperial charter

text: 1949 Radiocarbon dating

text: Radiocarbon dating

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: carbon is present

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: How long does carbon-14 decay to carbon-12?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating is used to determine the age of what

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: Which of the following is not used for radiocarbon dating?

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: Radiocarbon dating

answers: NDQ_005712

answers: Radiocarbon dating

answers: NDQ_005713

answers: 1949 Radiocarbon dating

answers: NDQ_005714

answers: 1949 Radiocarbon dating

answers: NDQ_005715

answers: 1949 Radiocarbon dating

answers: NDQ_005716

answers: Radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon dating

answers: NDQ_005718

answers: Radiocarbon

answers: NDQ_005719

answers: 1949 Radiocarbon dating

answers: NDQ_005720

answers: 1949 Radiocarbon dating

text: Nuclear scientist Rodger Sparks recognizes Athol Rafter’s contribution to radiocarbon dating in Radiocarbon dating – New Zealand beginnings, New Zealand Science Review, 61, 2 (2004)

text: Nuclear scientist Rodger Sparks recognizes Athol Rafter’s contribution to radiocarbon dating in Radiocarbon dating – New Zealand beginnings,

text: New Zealand Science Review

text: , 61, 2 (2004)

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: Rodger Sparks recognizes Athol Rafter’s contribution

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: Radiocarbon dating – New Zealand beginnings, New Zealand Science Review,

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: The Princeton Chert was originally considered to be Middle Eocene based on data from mammals, freshwater fish, and potassium-argon dates. Recently, more accurate radiometric techniques provided a date of 48.7 mya, placing the Princeton Chert in the Ypresian stage (47.8–56.0 mya), consistent with the whole Allenby Formation being now dated radiometrically as being Early Eocene.

text: The Princeton Chert was originally considered to be

text: Middle Eocene

text: based on data from

text: mammals

text: , freshwater fish, and potassium-argon dates. Recently, more accurate

text: radiometric

text: techniques provided a date of 48.7 mya, placing the Princeton Chert in the

text: Ypresian

text: stage (47.8–56.0 mya), consistent with the whole

text: Allenby Formation

text: being now dated radiometrically as being

text: Early Eocene

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: Ypresian stage

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dates

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: based on data from mammals, freshwater fish

answers: NDQ_005718

answers: Ypresian stage

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiometric techniques

answers: NDQ_005712

answers: Early Eocene.

answers: NDQ_005713

answers: Early Eocene.

answers: NDQ_005714

answers: radiometric techniques

answers: NDQ_005715

answers: Early Eocene.

answers: NDQ_005716

answers: radiometric techniques

answers: NDQ_005717

answers: The Princeton Chert was originally considered to be Middle Eocene

answers: NDQ_005718

answers: accurate

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: The Princeton Chert was originally considered to be Middle Eocene

text: It remains unclear when, why, and by whom the earliest dolmens were made. The oldest known dolmens are in Western Europe, where they were set in place around 7,000 years ago. Archaeologists still do not know who erected these dolmens, which makes it difficult to know why they did it. They are generally all regarded as tombs or burial chambers, despite the absence of clear evidence for this. Human remains, sometimes accompanied by artifacts, have been found in or close to the dolmens which could be scientifically dated using radiocarbon dating. However, it has been impossible to prove that these remains date from the time when the stones were originally set in place.

text: It remains unclear when, why, and by whom the earliest dolmens were made. The oldest known dolmens are in Western Europe, where they were set in place around 7,000 years ago. Archaeologists still do not know who erected these dolmens, which makes it difficult to know why they did it. They are generally all regarded as tombs or burial chambers, despite the absence of clear evidence for this. Human remains, sometimes accompanied by artifacts, have been found in or close to the dolmens which could be scientifically dated using

text: radiocarbon dating

text: . However, it has been impossible to prove that these remains date from the time when the stones were originally set in place.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: human remains, sometimes accompanied by artifacts

answers: NDQ_005718

answers: impossible to prove that these remains date from the time when the stones were originally set in place

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating.

answers: NDQ_005715

answers: 7,000 years ago.

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: radiocarbon dating.

answers: NDQ_005718

answers: impossible to prove that these remains

answers: NDQ_005719

answers: radiocarbon dating.

answers: NDQ_005720

answers: radiocarbon dating.

text: The young Earth creationist belief that the age of the Earth is 6,000 to 10,000 years old conflicts with the age of 4.54 billion years measured using independently cross-validated geochronological methods including radiometric dating. Creationists dispute these and all other methods which demonstrate the timescale of geologic history in spite of the lack of scientific evidence that there are any inconsistencies or errors in the measurement of the Earth's age.

text: The young Earth creationist belief that the age of the Earth is 6,000 to 10,000 years old conflicts with the

text: age of 4.54 billion years

text: measured using independently cross-validated

text: geochronological

text: methods including

text: radiometric dating

text: . Creationists dispute these and all other methods which demonstrate the timescale of

text: geologic history

text: in spite of the lack of

text: scientific evidence

text: that there are any inconsistencies or errors in the measurement of the Earth's age.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 6,000 to 10,000 years

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: inconsistencies or errors

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: independently cross-validated geochronological methods

answers: NDQ_005712

answers: independently cross-validated geochronological methods

answers: NDQ_005713

answers: independently cross-validated geochronological methods

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: 6,000 to 10,000 years old conflicts with the age of 4.54 billion years

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: radiometric dating.

answers: NDQ_005718

answers: inconsistencies or errors in the measurement of the Earth's age.

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: The preservation of these fossils is one of their great fascinations to science. As soft-bodied organisms, they would normally not fossilise and, unlike later soft-bodied fossil biota such as the Burgess Shale or Solnhofen Limestone, the Ediacaran biota is not found in a restricted environment subject to unusual local conditions: they were a global phenomenon. The processes that were operating must have been systemic and worldwide. There was something very different about the Ediacaran Period that permitted these delicate creatures to be left behind and it is thought the fossils were preserved by virtue of rapid covering by ash or sand, trapping them against the mud or microbial mats on which they lived. Their preservation was possibly enhanced by the high concentration of silica in the oceans before silica-secreting organisms such as sponges and diatoms became prevalent. Ash beds provide more detail and can readily be dated to the nearest million years or better using radiometric dating.However, it is more common to find Ediacaran fossils under sandy beds deposited by storms or high-energy bottom-scraping ocean currents known as turbidites. Soft-bodied organisms today almost never fossilise during such events, but the presence of widespread microbial mats probably aided preservation by stabilising their impressions in the sediment below.

text: The preservation of these fossils is one of their great fascinations to science. As soft-bodied organisms, they would normally not fossilise and, unlike later soft-bodied fossil biota such as the

text: Burgess Shale

text: or

text: Solnhofen Limestone

text: , the Ediacaran biota is not found in a restricted environment subject to unusual local conditions: they were a global phenomenon. The processes that were operating must have been systemic and worldwide. There was something very different about the Ediacaran Period that permitted these delicate creatures to be left behind and it is thought the fossils were preserved by virtue of rapid covering by ash or sand, trapping them against the mud or microbial mats on which they lived. Their preservation was possibly enhanced by the high concentration of silica in the oceans before silica-secreting organisms such as sponges and diatoms became prevalent. Ash beds provide more detail and can readily be dated to the nearest million years or better using

text: radiometric dating

text: .However, it is more common to find Ediacaran fossils under sandy beds deposited by storms or high-energy bottom-scraping ocean currents known as

text: turbidite

text: s. Soft-bodied organisms today almost never fossilise during such events, but the presence of widespread microbial mats probably aided preservation by stabilising their impressions in the sediment below.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: ash beds

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Ash beds provide more detail

answers: NDQ_005718

answers: more common to find Ediacaran fossils under sandy beds

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: Ash beds

answers: NDQ_005712

answers: Ash beds

answers: NDQ_005713

answers: radiometric dating.However,

answers: NDQ_005714

answers: radiometric dating.However,

answers: NDQ_005715

answers: radiometric dating.However,

answers: NDQ_005716

answers: radiometric dating.However,

answers: NDQ_005717

answers: radiometric dating.However,

answers: NDQ_005718

answers: it is more common to find Ediacaran fossils

answers: NDQ_005719

answers: radiometric dating.However,

answers: NDQ_005720

answers: radiometric dating.However,

text: The last match saw Kimiko Date-Krumm taking on Anabel Medina Garrigues. In the first set Krumm broke Garrigues serve early but failed to keep the advantage; however in the 9th game Date-Krumm broke the Medina Garrigues serve and eventually won the set 6–4. The second set then saw the two players trade breaks in the first four games, and then hold their respective serves for a 3–3. As Date-Krumm became more aggressive she broke the Medina Garrigues serve to lead 4–3 then broke again to win the set and match 6–3.

text: The last match saw

text: Kimiko Date-Krumm

text: taking on

text: Anabel Medina Garrigues

text: . In the first set Krumm broke Garrigues serve early but failed to keep the advantage; however in the 9th game Date-Krumm broke the Medina Garrigues serve and eventually won the set 6–4. The second set then saw the two players trade breaks in the first four games, and then hold their respective serves for a 3–3. As Date-Krumm became more aggressive she broke the Medina Garrigues serve to lead 4–3 then broke again to win the set and match 6–3.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: isotopes

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: 6–4.

answers: NDQ_005712

answers: 6–3.

answers: NDQ_005713

answers: 6–3.

answers: NDQ_005714

answers: 6–4.

answers: NDQ_005715

answers: 6–4.

answers: NDQ_005716

answers: 6–4.

answers: NDQ_005717

answers: 6–4.

answers: NDQ_005718

answers: failed to keep the advantage;

answers: NDQ_005719

answers: 6–3.

answers: NDQ_005720

answers: 6–4.

text: The dating framework provided by radiocarbon led to a change in the prevailing view of how innovations spread through prehistoric Europe. Researchers had previously thought that many ideas spread by diffusion through the continent, or by invasions of peoples bringing new cultural ideas with them. As radiocarbon dates began to prove these ideas wrong in many instances, it became apparent that these innovations must sometimes have arisen locally. This has been described as a "second radiocarbon revolution", and with regard to British prehistory, archaeologist Richard Atkinson has characterized the impact of radiocarbon dating as "radical ... therapy" for the "progressive disease of invasionism". More broadly, the success of radiocarbon dating stimulated interest in analytical and statistical approaches to archaeological data.  Taylor has also described the impact of AMS, and the ability to obtain accurate measurements from very small samples, as ushering in a third radiocarbon revolution.

text: The dating framework provided by radiocarbon led to a change in the prevailing view of how innovations spread through prehistoric Europe. Researchers had previously thought that many ideas spread by diffusion through the continent, or by invasions of peoples bringing new cultural ideas with them. As radiocarbon dates began to prove these ideas wrong in many instances, it became apparent that these innovations must sometimes have arisen locally. This has been described as a "second radiocarbon revolution", and with regard to British prehistory, archaeologist

text: Richard Atkinson

text: has characterized the impact of radiocarbon dating as "radical ... therapy" for the "progressive disease of invasionism". More broadly, the success of radiocarbon dating stimulated interest in analytical and statistical approaches to archaeological data.  Taylor has also described the impact of AMS, and the ability to obtain accurate measurements from very small samples, as ushering in a third radiocarbon revolution.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: How long does carbon-14 decay to carbon-12?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: the ability to obtain accurate measurements from very small samples, as ushering in a third radiocarbon revolution.

answers: NDQ_005718

answers: very small samples

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: very small samples,

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: third radiocarbon revolution.

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: these innovations must sometimes have arisen locally.

answers: NDQ_005718

answers: these innovations must sometimes have arisen locally.

answers: NDQ_005719

answers: AMS, and the ability to obtain accurate measurements from very small samples,

answers: NDQ_005720

answers: radiocarbon

text: Most ice concentration algorithms based on microwave radiometryare predicated on the dual observation that: 1. different surface typeshave different, strongly clustered, microwave signatures and2. the radiometric signature at the instrument head is a linearcombination of that of the different surface types, with the weightstaking on the values of the relative concentrations.If we form a vector space from each of the instrument channelsin which all but one of the signatures of the different surface typesare linearly independent, then it is straightforward to solve forthe relative concentrations:

text: Most ice concentration algorithms based on microwave radiometryare predicated on the dual observation that: 1. different surface typeshave different, strongly clustered, microwave signatures and2. the radiometric signature at the instrument head is a linearcombination of that of the different surface types, with the weightstaking on the values of the relative concentrations.If we form a vector space from each of the instrument channelsin which all but one of the signatures of the different surface typesare linearly independent, then it is straightforward to solve forthe relative concentrations:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: argon isotope

answers: NDQ_005718

answers: linearcombination

answers: NDQ_005719

answers: uranium-lead dating are useful for very young materials

answers: NDQ_005720

answers: context: uranium-lead

answers: NDQ_005711

answers: microwave radiometryare

answers: NDQ_005712

answers: linearly independent,

answers: NDQ_005713

answers: the radiometric signature

answers: NDQ_005714

answers: ice concentration algorithms based on microwave radiometryare

answers: NDQ_005715

answers: linearly independent,

answers: NDQ_005716

answers: microwave radiometryare

answers: NDQ_005717

answers: linearly independent, then it is straightforward to solve forthe relative concentrations:

answers: NDQ_005718

answers: weightstaking on the values of the relative concentrations.If

answers: NDQ_005719

answers: Most ice concentration algorithms based on microwave radiometryare

answers: NDQ_005720

answers: microwave radiometryare

text: The first evidence of the systematic use of Stone-Age technologies in the Philippines is estimated to have dated back to about 50,000 BC, and this phase in the development of proto-Philippine societies is considered to end with the rise of metal tools in about 500 BC, although stone tools continued to be used past that date. However, new discoveries in Luzon, particularly in Liwan, Kalinga, found stone tools that were dated through potassium argon test at most 920,000 years old, and at least 750,000 years old.

text: The first evidence of the systematic use of Stone-Age technologies in the Philippines is estimated to have dated back to about 50,000 BC, and this phase in the development of proto-Philippine societies is considered to end with the rise of metal tools in about 500 BC, although stone tools continued to be used past that date. However, new discoveries in Luzon, particularly in

text: Liwan, Kalinga

text: , found stone tools that were dated through potassium argon test at most 920,000 years old, and at least 750,000 years old.

answers: NDQ_005711

answers: potassium argon

answers: NDQ_005712

answers: potassium argon test

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium argon test

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: potassium argon

answers: NDQ_005717

answers: stone tools that were dated through potassium argon test

answers: NDQ_005718

answers: argon test at most 920,000 years old

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium argon test

answers: NDQ_005712

answers: potassium argon test

answers: NDQ_005713

answers: potassium argon test

answers: NDQ_005714

answers: potassium argon

answers: NDQ_005715

answers: 50,000 BC,

answers: NDQ_005716

answers: potassium argon

answers: NDQ_005717

answers: 920,000 years old, and at least 750,000 years old.

answers: NDQ_005718

answers: potassium argon test at most 920,000 years old,

answers: NDQ_005719

answers: potassium argon test at most 920,000 years old,

answers: NDQ_005720

answers: potassium argon

text: Nye cited radiometric dating, ice core data, and the light from distant stars to argue that the Earth must be much older than young Earth creationists like Ham theorize. Ham argued that these various dating methods are untrustworthy because they often give varying ages for the same artifacts.

text: Nye cited

text: radiometric dating

text: ice core

text: data, and the light from distant stars to argue that the Earth must be much older than young Earth creationists like Ham theorize. Ham argued that these various dating methods are untrustworthy because they often give varying ages for the same artifacts.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: ice core data

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: they often give varying ages

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: varying ages for the same artifacts.

answers: NDQ_005712

answers: varying ages for the same artifacts.

answers: NDQ_005713

answers: varying ages for the same artifacts.

answers: NDQ_005714

answers: they often give varying ages for the same artifacts.

answers: NDQ_005715

answers: Nye cited radiometric dating,

answers: NDQ_005716

answers: varying ages for the same artifacts.

answers: NDQ_005717

answers: varying ages for the same artifacts.

answers: NDQ_005718

answers: they often give varying ages for the same artifacts.

answers: NDQ_005719

answers: they often give varying ages for the same artifacts.

answers: NDQ_005720

answers: radiometric dating,

text: Because heating of a sample above the annealing temperature causes the fission damage to heal or anneal, the technique is useful for dating the most recent cooling event in the history of the sample. This resetting of the clock can be used to investigate the thermal history of basin sediments, kilometer-scale exhumation caused by tectonism and erosion, low temperature metamorphic events, and geothermal vein formation.  The fission track method has also been used to date archaeological sites and artifacts. It was used to confirm the potassium-argon dates for the deposits at Olduvai Gorge.

text: Because heating of a sample above the annealing temperature causes the fission damage to heal or anneal, the technique is useful for dating the most recent cooling event in the history of the sample. This resetting of the clock can be used to investigate the thermal history of

text: basin

text: sediment

text: s, kilometer-scale exhumation caused by

text: tectonism

text: and

text: erosion

text: , low temperature

text: metamorphic

text: events, and

text: geothermal

text: vein

text: formation.  The fission track method has also been used to date

text: archaeological

text: sites and artifacts. It was used to confirm the

text: potassium-argon

text: dates for the deposits at

text: Olduvai Gorge

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: fission damage to heal or anneal

answers: NDQ_005715

answers: NDQ_005716

answers: anneal

answers: NDQ_005717

answers: fission damage to heal or anneal

answers: NDQ_005718

answers: fission damage to heal or anneal

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: most recent cooling event in the history of the sample.

answers: NDQ_005713

answers: The fission track method

answers: NDQ_005714

answers: The fission track method

answers: NDQ_005715

answers: The fission track method

answers: NDQ_005716

answers: fission damage to heal or anneal,

answers: NDQ_005717

answers: The fission track method

answers: NDQ_005718

answers: heating of a sample above the annealing temperature

answers: NDQ_005719

answers: dating the most recent cooling event in the history of the sample.

answers: NDQ_005720

answers: potassium-argon dates for the deposits at Olduvai Gorge.

text: The presence of the incense shovel and ladle leads some to believe that they were part of some form of ritual ceremony.  This is supported by evidence of a Roman relief in which a sea captain is shown in front of an altar, praising his gods after a safe journey.  The various lead weights are believed to be associated with fishing nets.  They weights are very similar in form and function to those found on another Roman shipwreck located off the coast of Dor, Israel.  Due to a lack of materials that can be radio-carbon dated, the shipwreck has been dated to the 1st or 2nd century BC based on artifact typologies.

text: The presence of the

text: incense

text: shovel and ladle leads some to believe that they were part of some form of ritual ceremony.  This is supported by evidence of a Roman relief in which a sea captain is shown in front of an altar, praising his gods after a safe journey.  The various lead weights are believed to be associated with fishing nets.  They weights are very similar in form and function to those found on another Roman shipwreck located off the coast of

text: Dor, Israel

text: .  Due to a lack of materials that can be

text: radio-carbon

text: dated, the shipwreck has been dated to the 1st or 2nd century BC based on artifact typologies.

answers: NDQ_005711

answers: carbon

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: radio-carbon

answers: NDQ_005714

answers: radio-carbon

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: due to a lack of materials that can be radio-carbon dated

answers: NDQ_005718

answers: materials that can be radio-carbon dated

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radio-carbon

answers: NDQ_005712

answers: radio-carbon dated,

answers: NDQ_005713

answers: radio-carbon

answers: NDQ_005714

answers: radio-carbon dated,

answers: NDQ_005715

answers: lead weights

answers: NDQ_005716

answers: radio-carbon dated,

answers: NDQ_005717

answers: radio-carbon dated,

answers: NDQ_005718

answers: lack of materials that can be radio-carbon dated,

answers: NDQ_005719

answers: radio-carbon dated,

answers: NDQ_005720

answers: lead weights

text: The Biographical Directory normally uses the date of a special election, as the seniority date.  However, mostly in early Congresses, the date of the member taking his seat can be the one given. The date of the special election is mentioned in a note to the list below, when that date is not used as the seniority date by the Biographical Directory.

text: The Biographical Directory normally uses the date of a special election, as the seniority date.  However, mostly in early Congresses, the date of the member taking his seat can be the one given. The date of the special election is mentioned in a note to the list below, when that date is not used as the seniority date by the Biographical Directory.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: 5,730 years

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: date of the member taking his seat

answers: NDQ_005718

answers: date of the member taking his seat

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: The Biographical Directory normally uses the date of a special election,

answers: NDQ_005712

answers: early Congresses,

answers: NDQ_005713

answers: The Biographical Directory normally uses the date of a special election,

answers: NDQ_005714

answers: seniority date.

answers: NDQ_005715

answers: The Biographical Directory normally uses the date of a special election,

answers: NDQ_005716

answers: date of a special election, as the seniority date.

answers: NDQ_005717

answers: date of a special election,

answers: NDQ_005718

answers: the date of the member taking his seat can be the one given.

answers: NDQ_005719

answers: The Biographical Directory normally uses the date of a special election,

answers: NDQ_005720

answers: The Biographical Directory normally uses the date of a special election,

text: The photovoltaic assay, used only in the dated Photo Electric Intoximeter (PEI), is a form of breath testing rarely encountered today. The process works by using photocells to analyze the color change of a redox (oxidation-reduction) reaction. A breath sample is bubbled through an aqueous solution of sulfuric acid, potassium dichromate, and silver nitrate. The silver nitrate acts as a catalyst, allowing the alcohol to be oxidized at an appreciable rate. The requisite acidic condition needed for the reaction might also be provided by the sulfuric acid. In solution, ethanol reacts with the potassium dichromate, reducing the dichromate ion to the chromium (III) ion. This reduction results in a change of the solution's color from red-orange to green. The reacted solution is compared to a vial of non-reacted solution by a photocell, which creates an electric current proportional to the degree of the color change; this current moves the needle that indicates BAC.

text: The photovoltaic assay, used only in the dated

text: Photo Electric Intoximeter (PEI)

text: , is a form of breath testing rarely encountered today. The process works by using

text: photocells

text: to analyze the color change of a

text: redox

text: (oxidation-reduction) reaction. A breath sample is bubbled through an

text: aqueous

text: solution

text: of

text: sulfuric acid

text: potassium dichromate

text: , and

text: silver nitrate

text: . The

text: silver nitrate

text: acts as a

text: catalyst

text: , allowing the

text: alcohol

text: to be oxidized at an appreciable rate. The requisite acidic condition needed for the reaction might also be provided by the

text: sulfuric acid

text: . In

text: solution

text: ethanol

text: reacts with the

text: potassium dichromate

text: , reducing the

text: dichromate

text: ion

text: to the

text: chromium

text: (III)

text: ion

text: . This reduction results in a change of the

text: solution

text: 's color from red-orange to green. The reacted

text: solution

text: is compared to a

text: vial

text: of non-reacted

text: solution

text: by a

text: photocell

text: , which creates an

text: electric current

text: proportional to the degree of the color change; this current moves the needle that indicates BAC.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: photovoltaic assay

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: BAC

answers: NDQ_005717

answers: The silver nitrate acts as a catalyst

answers: NDQ_005718

answers: breath testing rarely encountered today

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: photocells

answers: NDQ_005712

answers: dated

answers: NDQ_005713

answers: Photo Electric Intoximeter

answers: NDQ_005714

answers: BAC.

answers: NDQ_005715

answers: Photo Electric Intoximeter

answers: NDQ_005716

answers: BAC.

answers: NDQ_005717

answers: ethanol reacts with the potassium dichromate,

answers: NDQ_005718

answers: breath testing rarely encountered today.

answers: NDQ_005719

answers: dated Photo Electric Intoximeter

answers: NDQ_005720

answers: Photo Electric Intoximeter

text: The boundary between the Wabigoon and Quetico subprovinces seems to have been also controlled by colliding plates and subsequent transpressions. This Rainy Lake – Seine River fault zone is a major northeast-southwest trending strike-slip fault zone; it trends N80°E to cut through the northwest part of Voyageurs National Park in Minnesota and extends westward to near International Falls, Minnesota and Fort Frances, Ontario. The fault has transported rocks in the greenstone belt a considerable distance from their origin. The greenstone belt is  wide at the Seven Sisters Islands; to the west the greenstone interfingers with pods of anorthositic gabbro. Radiometric dating from the Rainy Lake area in Ontario show an age of about 2,700 million years old, which favors a moving tectonic plate model for the formation of the boundary.

text: The boundary between the Wabigoon and Quetico subprovinces seems to have been also controlled by colliding plates and subsequent

text: transpression

text: s. This Rainy Lake – Seine River fault zone is a major northeast-southwest trending

text: strike-slip

text: fault zone; it trends N80°E to cut through the northwest part of

text: Voyageurs National Park

text: in Minnesota and extends westward to near

text: International Falls

text: , Minnesota and

text: Fort Frances

text: , Ontario. The fault has transported rocks in the greenstone belt a considerable distance from their origin. The greenstone belt is  wide at the Seven Sisters Islands; to the west the greenstone interfingers with pods of

text: anorthositic

text: gabbro

text: Radiometric dating

text: from the Rainy Lake area in Ontario show an age of about 2,700 million years old, which favors a moving tectonic plate model for the formation of the boundary.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages because

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: How long does the half-life of carbon-14 decay?

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: an age of about 2,700 million years old

answers: NDQ_005718

answers: age of about 2,700 million years old

answers: NDQ_005719

answers: How is radiometric dating used?

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 2,700 million years old,

answers: NDQ_005712

answers: a moving tectonic plate model

answers: NDQ_005713

answers: 2,700 million years old,

answers: NDQ_005714

answers: Radiometric

answers: NDQ_005715

answers: 2,700 million years old,

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: 2,700 million years old,

answers: NDQ_005718

answers: moving tectonic plate model

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: 2,700 million years old,

text: Aluminium (Al) has 22 known isotopes from Al to Al and 4 known isomers. Only Al (stable isotope) and Al (radioactive isotope, t = 7.2 × 10 y) occur naturally, however Al has a natural abundance of 99.9+ %. Other than Al, all radioisotopes have half-lives under 7 minutes, most under a second.  Relative atomic mass is 26.9815386(8). Al is produced from argon in the atmosphere by spallation caused by cosmic-ray protons. Aluminium isotopes have found practical application in dating marine sediments, manganese nodules, glacial ice, quartz in rock exposures, and meteorites. The ratio of Al to Be has been used to study the role of sediment transport, deposition, and storage, as well as burial times, and erosion, on 10 to 10 year time scales.

text: Aluminium

text: (Al) has 22 known

text: isotope

text: s from Al to Al and 4 known

text: isomers

text: . Only Al (

text: stable isotope

text: ) and Al (

text: radioactive

text: isotope,

text: t

text: = 7.2 × 10

text: y

text: ) occur naturally, however Al has a natural abundance of 99.9+ %. Other than Al, all radioisotopes have half-lives under 7 minutes, most under a second.

text: Relative atomic mass

text: is 26.9815386(8). Al is produced from

text: argon

text: in the

text: atmosphere

text: by

text: spallation

text: caused by

text: cosmic-ray

text: proton

text: s. Aluminium isotopes have found practical application in dating

text: marine

text: sediment

text: s,

text: manganese nodule

text: s, glacial ice,

text: quartz

text: in

text: rock

text: exposures, and

text: meteorite

text: s. The ratio of Al to

text: Be

text: has been used to study the role of sediment

text: transport

text: deposition

text: , and storage, as well as burial times, and erosion, on 10 to 10 year time scales.

answers: NDQ_005711

answers: radioactive isotopes

answers: NDQ_005712

answers: 10 to 10 year

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: aluminium isotopes have found practical application

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: burial times

answers: NDQ_005717

answers: aluminium isotopes have found practical application

answers: NDQ_005718

answers: half-lives under 7 minutes, most under a second

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 10 to 10 year time scales.

answers: NDQ_005712

answers: 10 to 10 year time scales.

answers: NDQ_005713

answers: Aluminium isotopes

answers: NDQ_005714

answers: Aluminium isotopes

answers: NDQ_005715

answers: 7 minutes,

answers: NDQ_005716

answers: burial times,

answers: NDQ_005717

answers: Aluminium isotopes

answers: NDQ_005718

answers: half-lives under 7 minutes,

answers: NDQ_005719

answers: Aluminium isotopes have found practical application in dating marine sediments,

answers: NDQ_005720

answers: Aluminium isotopes have found practical application in dating marine sediments,

text: Researchers have studied other radioactive isotopes created by cosmic rays to determine if they could also be used to assist in dating objects of archaeological interest; such isotopes include , , , , and .  With the development of AMS in the 1980s it became possible to measure these isotopes precisely enough for them to be the basis of useful dating techniques, which have been primarily applied to dating rocks.  Naturally occurring radioactive isotopes can also form the basis of dating methods, as with potassium–argon dating, argon–argon dating, and uranium series dating.  Other dating techniques of interest to archaeologists include thermoluminescence, optically stimulated luminescence, electron spin resonance, and fission track dating, as well as techniques that depend on annual bands or layers, such as dendrochronology, tephrochronology, and varve chronology.

text: Researchers have studied other radioactive isotopes created by cosmic rays to determine if they could also be used to assist in dating objects of archaeological interest; such isotopes include

text: , and

text: .  With the development of AMS in the 1980s it became possible to measure these isotopes precisely enough for them to be the basis of useful dating techniques, which have been primarily applied to dating rocks.  Naturally occurring radioactive isotopes can also form the basis of dating methods, as with

text: potassium–argon dating

text: argon–argon dating

text: , and

text: uranium series dating

text: .  Other dating techniques of interest to archaeologists include

text: thermoluminescence

text: optically stimulated luminescence

text: electron spin resonance

text: , and

text: fission track dating

text: , as well as techniques that depend on annual bands or layers, such as

text: dendrochronology

text: tephrochronology

text: , and

text: varve

text: chronology.

answers: NDQ_005711

answers: radioactive isotopes

answers: NDQ_005712

answers: uranium series dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: isotopes created by cosmic rays

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: naturally occurring radioactive isotopes can also form the basis

answers: NDQ_005718

answers: primarily applied to dating rocks

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: radioactive isotopes created by cosmic rays

answers: NDQ_005712

answers: rocks.

answers: NDQ_005713

answers: AMS

answers: NDQ_005714

answers: rocks.

answers: NDQ_005715

answers: AMS

answers: NDQ_005716

answers: radioactive isotopes created by cosmic rays

answers: NDQ_005717

answers: Naturally occurring radioactive isotopes

answers: NDQ_005718

answers: annual bands or layers,

answers: NDQ_005719

answers: uranium series dating.

answers: NDQ_005720

answers: uranium series dating.

text: The later Tara ignimbrite (including the Upper Tara Ignimbrite, the Filo Delgado Ignimbrite and the Pampa Tortoral Tuff) forms the western dome of the Guacha caldera and spreads mostly north and southeast, between Argentina, Bolivia and Chile. It has a minimum volume of  and covers a surface area of at least  in Chile and  in Bolivia where it was at first not recognized. Some outflows are more than  thick. Several different dates have been determined on the basis of argon-argon dating, including 3.55±0.01 on biotite and 3.49±0.01 mya on sanidine, which is the preferred age. The Chajnantor lavas and the Rio Guacha dome in the caldera have been K-Ar dated at 3.67±0.13 and 3.61±0.02 mya respectively. This ignimbrite ponded inside the Guacha caldera, and one particularly thick layer (>) is found beneath Zapaleri stratovolcano. This ignimbrite was formerly known as Upper Tara. Geological considerations indicate that this ignimbrite formed from pre-existent melts and an influx of andesitic magma.

text: The later Tara ignimbrite (including the Upper Tara Ignimbrite, the Filo Delgado Ignimbrite and the Pampa Tortoral Tuff) forms the western dome of the Guacha caldera and spreads mostly north and southeast, between

text: Argentina

text: Bolivia

text: and

text: Chile

text: . It has a minimum volume of  and covers a surface area of at least  in Chile and  in Bolivia where it was at first not recognized. Some outflows are more than  thick. Several different dates have been determined on the basis of

text: argon-argon dating

text: , including 3.55±0.01 on

text: biotite

text: and 3.49±0.01

text: mya

text: on

text: sanidine

text: , which is the preferred age. The Chajnantor lavas and the Rio Guacha dome in the caldera have been

text: K-Ar dated

text: at 3.67±0.13 and 3.61±0.02

text: mya

text: respectively. This ignimbrite ponded inside the Guacha caldera, and one particularly thick layer (>) is found beneath

text: Zapaleri

text: stratovolcano. This ignimbrite was formerly known as Upper Tara. Geological considerations indicate that this ignimbrite formed from pre-existent melts and an influx of

text: andesitic

text: magma.

answers: NDQ_005711

answers: K-Ar

answers: NDQ_005712

answers: sanidine

answers: NDQ_005713

answers: What is the preferred age?

answers: NDQ_005714

answers: argon-argon dating

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: sanidine

answers: NDQ_005717

answers: 3.67 0.13 and 3.61 0.02 mya respectively

answers: NDQ_005718

answers: K-Ar dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: argon-argon

answers: NDQ_005712

answers: argon-argon

answers: NDQ_005713

answers: argon-argon dating,

answers: NDQ_005714

answers: argon-argon

answers: NDQ_005715

answers: argon-argon

answers: NDQ_005716

answers: argon-argon

answers: NDQ_005717

answers: 3.67<unk>0.13 and 3.61<unk>0.02 mya

answers: NDQ_005718

answers: Some outflows are more than thick.

answers: NDQ_005719

answers: argon-argon dating,

answers: NDQ_005720

answers: argon-argon dating,

text: It is, however, enacted by the Immovable Property (Removal or Modification of Restrictions) Act that, after the commencement of the Act (October 1, 1965), any fideicommissum created in favour of more than two successive fideicommissaries shall be limited to two, whatever the wording of the will. Where the fideicommissum was created before the commencement of the Act, only two successive fideicomrnissaries are permitted from the date of the will. If, at the date of commencement, two or more fideicommissary substitutions have already taken place, the fideicommissum shall be terminated at the date of commencement.

text: It is, however, enacted by the Immovable Property (Removal or Modification of Restrictions) Act that, after the commencement of the Act (October 1, 1965), any fideicommissum created in favour of more than two successive fideicommissaries shall be limited to two, whatever the wording of the will. Where the fideicommissum was created before the commencement of the Act, only two successive fideicomrnissaries are permitted from the date of the will. If, at the date of commencement, two or more fideicommissary substitutions have already taken place, the fideicommissum shall be terminated at the date of commencement.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: two successive fideicommissaries

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: When the fideicommissum was created before the commencement of the Act

answers: NDQ_005718

answers: two successive fideicommissaries shall be limited to two

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: two successive fideicommissaries shall be limited to two,

answers: NDQ_005712

answers: two successive fideicommissaries shall be limited to two,

answers: NDQ_005713

answers: two successive fideicommissaries shall be limited to two,

answers: NDQ_005714

answers: Immovable Property

answers: NDQ_005715

answers: two successive fideicommissaries shall be limited to two,

answers: NDQ_005716

answers: date of the will.

answers: NDQ_005717

answers: only two successive fideicomrnissaries

answers: NDQ_005718

answers: two,

answers: NDQ_005719

answers: two successive fideicommissaries shall be limited to two,

answers: NDQ_005720

answers: two successive fideicommissaries shall be limited to two,

text: Radiometric dates of 1883-1870 Ma are reported for mafic, ultramafic, carbonatite and lamprophyre intrusions within the Trough.

text: Radiometric dates

text: of 1883-1870 Ma are reported for

text: mafic

text: ultramafic

text: carbonatite

text: and

text: lamprophyre

text: intrusions within the Trough.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: carbonatite intrusions

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 1883-1870 Ma

answers: NDQ_005718

answers: radiometric dating cannot be used to determine the age of rocks

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiometric dates of 1883-1870 Ma

answers: NDQ_005712

answers: 1883-1870 Ma

answers: NDQ_005713

answers: Radiometric dates of 1883-1870 Ma

answers: NDQ_005714

answers: Radiometric dates

answers: NDQ_005715

answers: 1883-1870 Ma

answers: NDQ_005716

answers: Radiometric dates

answers: NDQ_005717

answers: 1883-1870 Ma

answers: NDQ_005718

answers: Radiometric dates of 1883-1870 Ma

answers: NDQ_005719

answers: Radiometric dates of 1883-1870 Ma

answers: NDQ_005720

answers: Radiometric dates of 1883-1870 Ma

text: He died at the age of 43, being survived by his wife, Joyce Rinehart, and two sons and a daughter. During his career he pioneered the study of rare earth elements in examining the crust, mantle, and interior of the planet. He led the development of the use of rubidium-strontium and uranium-lead radiometric dating methods for rocks, particularly for samples returned from the Moon. His examinations of trace elements resulted in new understands of how volcanic fluids originate.

text: He died at the age of 43, being survived by his wife, Joyce Rinehart, and two sons and a daughter. During his career he pioneered the study of rare earth elements in examining the crust, mantle, and interior of the planet. He led the development of the use of

text: rubidium-strontium

text: and uranium-lead

text: radiometric dating

text: methods for rocks, particularly for samples returned from the Moon. His examinations of trace elements resulted in new understands of how volcanic fluids originate.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: rubidium-strontium

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: He led the development of the use of rubidium-strontium

answers: NDQ_005718

answers: samples returned from the Moon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead

answers: NDQ_005712

answers: samples returned from the Moon.

answers: NDQ_005713

answers: uranium-lead

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: Joyce Rinehart,

answers: NDQ_005716

answers: dating

answers: NDQ_005717

answers: rubidium-strontium

answers: NDQ_005718

answers: samples returned from the Moon.

answers: NDQ_005719

answers: rubidium-strontium

answers: NDQ_005720

answers: uranium-lead radiometric dating

text: Radiocarbon dated samples from the cromlech show the tomb was accessed by many generations over a period of 300–800 years, and that the human bones are the disarticulated remains (i.e., not complete skeletons) of at least 40 individuals: male and female adults, adolescents, children, and infants. One of the red deer bones has been radiocarbon dated to between 2750 BP and 2150 BP, showing that at least some of the bones entered long after the site had been deserted.

text: Radiocarbon dated

text: samples from the cromlech show the tomb was accessed by many generations over a period of 300–800 years, and that the human bones are the disarticulated remains (i.e., not complete skeletons) of at least 40 individuals: male and female adults, adolescents, children, and infants. One of the red deer bones has been radiocarbon dated to between 2750 BP and 2150 BP, showing that at least some of the bones entered long after the site had been deserted.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon

answers: NDQ_005718

answers: not complete skeletons

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: 300–800 years,

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: disarticulated remains

answers: NDQ_005715

answers: 300–800 years,

answers: NDQ_005716

answers: disarticulated remains

answers: NDQ_005717

answers: Radiocarbon

answers: NDQ_005718

answers: complete skeletons)

answers: NDQ_005719

answers: radiocarbon dated to between 2750 BP and 2150 BP,

answers: NDQ_005720

answers: radiocarbon dated to between 2750 BP and 2150 BP,

text: Samples used for radiocarbon dating must be handled carefully to avoid contamination.  Not all material can be dated by this method; only samples containing organic matter can be tested: the date found will be the date of death of the plants or animals from which the sample originally came.

text: Samples used for

text: radiocarbon dating

text: must be handled carefully to avoid contamination.  Not all material can be dated by this method; only samples containing organic matter can be tested: the date found will be the date of death of the plants or animals from which the sample originally came.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: organic matter

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: only organic matter can be tested

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: only samples containing organic matter can be tested

answers: NDQ_005718

answers: Not all material can be dated by this method

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: date of death

answers: NDQ_005712

answers: samples containing organic matter

answers: NDQ_005713

answers: Not all material can be dated by this method;

answers: NDQ_005714

answers: only samples containing organic matter

answers: NDQ_005715

answers: Not all material can be dated by this method;

answers: NDQ_005716

answers: only samples containing organic matter

answers: NDQ_005717

answers: only samples containing organic matter

answers: NDQ_005718

answers: Not all material can be dated by this method;

answers: NDQ_005719

answers: Not all material can be dated by this method;

answers: NDQ_005720

answers: Not all material can be dated by this method;

text: Fission track dating is a radiometric dating technique based on analyses of the damage trails, or tracks, left by fission fragments in certain uranium-bearing minerals and glasses.  Fission-track dating is a relatively simple method of radiometric dating that has made a significant impact on understanding the thermal history of continental crust, the timing of volcanic events,  and the source and age of different archeological artifacts.  The method involves using the number of fission events produced from the spontaneous decay of uranium-238 in common accessory minerals to date the time of rock cooling below closure temperature.  Fission tracks are sensitive to heat, and therefore the technique is useful at unraveling the thermal evolution of rocks and minerals.   Most current research using fission tracks is aimed at: a) understanding the evolution of mountain belts; b) determining the source or provenance of sediments; c) studying the thermal evolution of basins; d) determining the age of poorly dated strata; and e) dating and provenance determination of archeological artifacts.

text: Fission track dating is a

text: radiometric dating

text: technique based on analyses of the damage trails, or tracks, left by

text: fission

text: fragments in certain

text: uranium

text: -bearing

text: mineral

text: s and

text: glass

text: es.  Fission-track dating is a relatively simple method of radiometric dating that has made a significant impact on understanding the thermal history of

text: continental crust

text: , the timing of

text: volcanic

text: events,  and the source and age of different

text: archeological

text: artifacts.  The method involves using the number of fission events produced from the spontaneous decay of

text: in common accessory minerals to date the time of rock cooling below

text: closure temperature

text: .  Fission tracks are sensitive to heat, and therefore the technique is useful at unraveling the thermal evolution of rocks and minerals.   Most current research using fission tracks is aimed at: a) understanding the evolution of mountain belts; b) determining the source or

text: provenance

text: of sediments; c) studying the thermal evolution of

text: basins

text: ; d) determining the age of poorly dated

text: strata

text: ; and e) dating and provenance determination of archeological artifacts.

answers: NDQ_005711

answers: Fission track dating

answers: NDQ_005712

answers: fission tracks are sensitive to heat

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Fission tracks are sensitive to heat

answers: NDQ_005715

answers: uranium-238

answers: NDQ_005716

answers: fission

answers: NDQ_005717

answers: Fission tracks are sensitive to heat

answers: NDQ_005718

answers: sensitive to heat

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: damage trails, or tracks, left by fission fragments

answers: NDQ_005712

answers: Fission tracks are sensitive to heat,

answers: NDQ_005713

answers: spontaneous decay of uranium-238

answers: NDQ_005714

answers: Fission tracks are sensitive to heat,

answers: NDQ_005715

answers: uranium-238

answers: NDQ_005716

answers: rock cooling below closure temperature.

answers: NDQ_005717

answers: spontaneous decay of uranium-238

answers: NDQ_005718

answers: Fission tracks are sensitive to heat,

answers: NDQ_005719

answers: Fission track dating

answers: NDQ_005720

answers: uranium-238

text: The monument is circled by the ancient wall from the c. XII-XIV. Unfortunately only parts of the original walls still exist today. The urban configuration of the site  is almost identical to the original layout. Without a doubt, the Medieval Bridge isthe emblem of the town, of an angular design with seven uneven arcs and two towers. The part of the town nearest to the bridge there are many narrow streets that belong to the ancient Jewish quarter. It is in this area where you will find the Miqvé, the purification baths, which date from c. XII, and demonstrate the presence of an important Jewish community. The street from the medieval bridge leads to the Town Square “Plaça Major”, a square whose arcades date from c. XVI, and used to be the centre of the medieval town. Important buildings are the Local Government “Ajuntament” dating from c. XVII, the Royal Curia “Cúria Reial”, dating from c. XIV, and the "Casa Tallaferro". The street “Tallaferro” leads to the entrance to the Castle precinct. Inside the precinct there remains one of the towers from the ancient County Castle, and the apse of Saint Mary “Santa Maria” that dates from c. XI. Along with the street “Portalet” these are the remains which best retain the medieval appearance,along with panoramic views of the Romanic Bridge. Leading up from the Main Street “Carrer Major”, there are the “Casa Romà” (c. XIV) and the parish church of Saint Vincent “Sant Vicenç” dating from c. XI-XII which has very sculpturesque doors and windows.Near to the Main Town Square, there is the “Prat de Sant Pere”, wide and spacious which used to be the Cemetery of the Benedictine monastery of Saint Peter “Sant Pere”. Today there only remains the three-nave church and one apse, dating from the c. XI. Also there is the small chapel of Saint James “Sant Jaume” (c. XII) and the “Casa Cornellà” (Llaudes) dating fromthe c. XII and which has a patio with three galleries. Behind the monastery there is the church of the hospital of Saint Julia “Sant Julià”, with one nave and no apse, dating from c. XII, and an outstanding entrance portal.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: c. XIV

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: XI

answers: NDQ_005718

answers: only parts of the original walls still exist

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: “Casa Romà”

answers: NDQ_005712

answers: c. XII-XIV.

answers: NDQ_005713

answers: entrance to the Castle precinct.

answers: NDQ_005714

answers: “Casa Romà” (c. XIV)

answers: NDQ_005715

answers: “Casa Romà” (c. XIV)

answers: NDQ_005716

answers: “C<unk>ria Reial”,

answers: NDQ_005717

answers: c. XI.

answers: NDQ_005718

answers: only parts of the original walls still exist today.

answers: NDQ_005719

answers: XI-XII

answers: NDQ_005720

answers: “Casa Romà”

text: A simple numbering based on periodic table position was never entirely satisfactory, however. Besides the case of iodine and tellurium, later several other pairs of elements (such as argon and potassium, cobalt and nickel) were known to have nearly identical or reversed atomic weights, thus requiring their placement in the periodic table to be determined by their chemical properties. However the gradual identification of more and more chemically similar lanthanide elements, whose atomic number was not obvious, led to inconsistency and uncertainty in the periodic numbering of elements at least from lutetium (element 71) onwards (hafnium was not known at this time).

text: A simple numbering based on periodic table position was never entirely satisfactory, however. Besides the case of iodine and tellurium, later several other pairs of elements (such as argon and potassium, cobalt and nickel) were known to have nearly identical or reversed atomic weights, thus requiring their placement in the periodic table to be determined by their chemical properties. However the gradual identification of more and more chemically similar

text: lanthanide

text: elements, whose atomic number was not obvious, led to inconsistency and uncertainty in the periodic numbering of elements at least from

text: lutetium

text: (element 71) onwards (

text: hafnium

text: was not known at this time).

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: iodine

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: iodine and tellurium

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: periodic table position

answers: NDQ_005717

answers: argon and potassium, cobalt and nickel

answers: NDQ_005718

answers: inconsistency and uncertainty

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: chemical properties.

answers: NDQ_005712

answers: chemical properties.

answers: NDQ_005713

answers: A simple numbering based on periodic table position was never entirely satisfactory,

answers: NDQ_005714

answers: chemical properties.

answers: NDQ_005715

answers: lutetium

answers: NDQ_005716

answers: numbering based on periodic table

answers: NDQ_005717

answers: nearly identical or reversed atomic weights,

answers: NDQ_005718

answers: inconsistency and uncertainty

answers: NDQ_005719

answers: argon and potassium, cobalt and nickel)

answers: NDQ_005720

answers: lutetium

text: Due to the long half-life, the technique is most applicable for dating minerals and rocks more than 100,000 years old. For shorter timescales, it is unlikely that enough argon-40 will have had time to accumulate in order to be accurately measurable. K–Ar dating was instrumental in the development of the geomagnetic polarity time scale. Although it finds the most utility in geological applications, it plays an important role in archaeology. One archeological application has been in bracketing the age of archeological deposits at Olduvai Gorge by dating lava flows above and below the deposits. It has also been indispensable in other early east African sites with a history of volcanic activity such as Hadar, Ethiopia. The K–Ar method continues to have utility in dating clay mineral diagenesis. Clay minerals are less than 2 micrometres thick and cannot easily be irradiated for Ar–Ar analysis because Ar recoils from the crystal lattice.

text: Due to the long

text: half-life

text: , the technique is most applicable for dating minerals and rocks more than 100,000 years old. For shorter timescales, it is unlikely that enough argon-40 will have had time to accumulate in order to be accurately measurable. K–Ar dating was instrumental in the development of the

text: geomagnetic polarity time scale

text: . Although it finds the most utility in

text: geological

text: applications, it plays an important role in

text: archaeology

text: . One archeological application has been in bracketing the age of archeological deposits at

text: Olduvai Gorge

text: by dating

text: lava

text: flows above and below the deposits. It has also been indispensable in other early east

text: Africa

text: n sites with a history of

text: volcanic

text: activity such as

text: Hadar, Ethiopia

text: . The K–Ar method continues to have utility in dating clay mineral

text: diagenesis

text: . Clay minerals are less than 2 micrometres thick and cannot easily be irradiated for

text: Ar–Ar

text: analysis because Ar recoils from the crystal lattice.

answers: NDQ_005711

answers: argon-40

answers: NDQ_005712

answers: the technique is most applicable for dating minerals and rocks more than 100,000 years old

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: argon-40 will have had time to accumulate in order to be accurately measurable

answers: NDQ_005715

answers: K–Ar

answers: NDQ_005716

answers: argon-40

answers: NDQ_005717

answers: it is unlikely that enough argon-40 will have had time to accumulate in order to be accurately measurable

answers: NDQ_005718

answers: the technique is most applicable for dating minerals and rocks more than 100,000 years old

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: long half-life,

answers: NDQ_005712

answers: more than 100,000 years old.

answers: NDQ_005713

answers: the technique is most applicable for dating minerals and rocks more than 100,000 years old.

answers: NDQ_005714

answers: long half-life,

answers: NDQ_005715

answers: K–Ar dating

answers: NDQ_005716

answers: half-life,

answers: NDQ_005717

answers: the technique is most applicable for dating minerals and rocks more than 100,000 years old.

answers: NDQ_005718

answers: For shorter timescales,

answers: NDQ_005719

answers: shorter timescales,

answers: NDQ_005720

answers: K–Ar dating

text: As discussed by Gaiser and others, radiocarbon dates reported from any Carolina bay are all minimum dates for their formation.  Because only organic matter can be dated by radiocarbon dating, the reported radiocarbon dates only represents times during which organic matter of some type accumulated in Carolina bays and was later preserved. At other times, datable organic matter would either not have been preserved as sediment accumulated within them, or older organic matter destroyed when they dried out completely. During glacial periods when sea level was 130 meters (400 ft) below present, the water table would have been below the bottom of the vast majority of the bays. At such times, any organic matter would have been destroyed by oxidization and weathering of the lake bottom. Also, at that time eolian processes would have eroded any existing sediments filling the bottom of many bays removing any older lake sediments and the pollen, and datable organic matter. As a result, it is highly unlikely that organic matter dating to the exact age of any Carolina Bay would have been preserved except in the deepest of them. Thus, the oldest radiocarbon date from a Carolina Bay only indicates when the water table rose high enough for a permanent lake or swamp to exist within it.

text: As discussed by Gaiser and others, radiocarbon dates reported from any Carolina bay are all minimum dates for their formation.  Because only organic matter can be dated by radiocarbon dating, the reported radiocarbon dates only represents times during which organic matter of some type accumulated in Carolina bays and was later preserved. At other times, datable organic matter would either not have been preserved as sediment accumulated within them, or older organic matter destroyed when they dried out completely. During glacial periods when

text: sea level

text: was 130 meters (400 ft) below present, the water table would have been below the bottom of the vast majority of the bays. At such times, any organic matter would have been destroyed by oxidization and weathering of the lake bottom. Also, at that time eolian processes would have eroded any existing sediments filling the bottom of many bays removing any older lake sediments and the pollen, and datable organic matter. As a result, it is highly unlikely that organic matter dating to the exact age of any Carolina Bay would have been preserved except in the deepest of them. Thus, the oldest radiocarbon date from a Carolina Bay only indicates when the water table rose high enough for a permanent lake or swamp to exist within it.

answers: NDQ_005711

answers: radiocarbon dating

answers: NDQ_005712

answers: organic matter can be dated

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: only organic matter can be dated

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: only organic matter can be dated

answers: NDQ_005717

answers: only organic matter can be dated by potassium-argon dating

answers: NDQ_005718

answers: highly unlikely that organic matter dating to the exact age of any Carolina Bay would have been preserved except in the deepest of them

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: organic matter can be dated by radiocarbon dating,

answers: NDQ_005712

answers: organic matter

answers: NDQ_005713

answers: radiocarbon dating,

answers: NDQ_005714

answers: only organic matter

answers: NDQ_005715

answers: radiocarbon dates

answers: NDQ_005716

answers: organic matter

answers: NDQ_005717

answers: organic matter

answers: NDQ_005718

answers: only organic matter

answers: NDQ_005719

answers: radiocarbon dating,

answers: NDQ_005720

answers: radiocarbon dating,

text: Radiometric dating measures the steady decay of radioactive elements in an object to determine its age. It is used to calculate dates for the older part of the planet’s geological record. The theory is very complicated but, in essence, the radioactive elements within an object decay to form isotopes of each chemical element. Isotopes are atoms of the element that differ in mass but share the same general properties. Geologists are most interested in the decay of isotopes carbon-14 (into nitrogen-14) and potassium-40 (into argon-40). Carbon-14 aka radiocarbon dating works for organic materials that are less than about 50,000 years old. For older periods, the potassium-argon dating process is more accurate.

text: Radiometric dating

text: measures the steady decay of

text: radioactive element

text: s in an object to determine its age. It is used to calculate dates for the older part of the planet’s geological record. The theory is very complicated but, in essence, the radioactive elements within an object decay to form

text: isotope

text: s of each

text: chemical element

text: . Isotopes are

text: atom

text: s of the element that differ in

text: mass

text: but share the same general properties. Geologists are most interested in the decay of isotopes

text: (into

text: ) and

text: (into

text: ). Carbon-14 aka

text: radiocarbon dating

text: works for organic materials that are less than about 50,000 years old. For older periods, the

text: potassium-argon dating

text: process is more accurate.

answers: NDQ_005711

answers: decay of radioactive elements

answers: NDQ_005712

answers: less than about 50,000 years

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: less than about 50,000 years old

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: For older periods, the potassium-argon dating process is more accurate

answers: NDQ_005718

answers: isotopes of each chemical element

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: measures the steady decay of radioactive elements

answers: NDQ_005712

answers: less than about 50,000 years old.

answers: NDQ_005713

answers: Radiometric dating measures the steady decay of radioactive elements

answers: NDQ_005714

answers: organic materials that are less than about 50,000 years old.

answers: NDQ_005715

answers: carbon-14 (into nitrogen-14)

answers: NDQ_005716

answers: steady decay of radioactive elements in an object to determine its age.

answers: NDQ_005717

answers: For older periods, the potassium-argon dating process is more accurate.

answers: NDQ_005718

answers: The theory is very complicated

answers: NDQ_005719

answers: Carbon-14

answers: NDQ_005720

answers: Radiometric dating

text: In radiometric dating, closure temperature or blocking temperature refers to the temperature of a system, such as a mineral, at the time given by its radiometric date. In physical terms, the closure temperature is the temperature at which a system has cooled so that there is no longer any significant diffusion of the parent or daughter isotopes out of the system and into the external environment.  The concept's initial mathematical formulation was presented in a seminal paper by Martin H. Dodson, "Closure temperature in cooling geochronological and petrological systems" in the journal Contributions to Mineralogy and Petrology, 1973, with refinements to a usable experimental formulation by other scientists in later years. This temperature varies broadly among different minerals and also differs depending on the parent and daughter atoms being considered. It is specific to a particular material and isotopic system.

text: In

text: radiometric dating

text: , closure temperature or blocking temperature refers to the temperature of a system, such as a

text: mineral

text: , at the time given by its radiometric date. In physical terms, the closure temperature is the temperature at which a system has cooled so that there is no longer any significant diffusion of the parent or daughter

text: isotopes

text: out of the system and into the external environment.  The concept's initial mathematical formulation was presented in a seminal paper by

text: Martin H. Dodson

text: , "Closure temperature in cooling geochronological and petrological systems" in the journal

entity_name: Contributions to Mineralogy and Petrology

text: Contributions to Mineralogy and Petrology

text: , 1973, with refinements to a usable experimental formulation by other scientists in later years. This temperature varies broadly among different minerals and also differs depending on the parent and daughter atoms being considered. It is specific to a particular material and isotopic system.

answers: NDQ_005711

answers: radiometric date

answers: NDQ_005712

answers: temperature varies broadly among different minerals

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: closure temperature or blocking temperature refers to the temperature of a system, such as a mineral

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: closure temperature

answers: NDQ_005717

answers: closure temperature or blocking temperature

answers: NDQ_005718

answers: This temperature varies broadly among different minerals

answers: NDQ_005719

answers: It is specific to a particular material and isotopic system.

answers: NDQ_005720

answers: NDQ_005711

answers: radiometric date.

answers: NDQ_005712

answers: It is specific to a particular material and isotopic system.

answers: NDQ_005713

answers: closure temperature or blocking temperature

answers: NDQ_005714

answers: radiometric dating,

answers: NDQ_005715

answers: In radiometric dating,

answers: NDQ_005716

answers: the closure temperature is the temperature at which a system has cooled

answers: NDQ_005717

answers: closure temperature or blocking temperature

answers: NDQ_005718

answers: It is specific to a particular material and isotopic system.

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: radiometric dating,

text: By measuring the amount of radioactive decay of a radioactive isotope with a known half-life, geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods. More slowly decaying isotopes are useful for longer periods of time, but less accurate in absolute years. With the exception of the radiocarbon method, most of these techniques are actually based on measuring an increase in the abundance of a radiogenic isotope, which is the decay-product of the radioactive parent isotope. Two or more radiometric methods can be used in concert to achieve more robust results. Most radiometric methods are suitable for geological time only, but some such as the radiocarbon method and the Ar/Ar dating method can be extended into the time of early human life and into recorded history.

text: By measuring the amount of

text: radioactive decay

text: of a

text: radioactive isotope

text: with a known

text: half-life

text: , geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods. More slowly decaying isotopes are useful for longer periods of time, but less accurate in absolute years. With the exception of the

text: radiocarbon method

text: , most of these techniques are actually based on measuring an increase in the abundance of a

text: radiogenic

text: isotope, which is the decay-product of the radioactive parent isotope. Two or more radiometric methods can be used in concert to achieve more robust results. Most radiometric methods are suitable for geological time only, but some such as the radiocarbon method and the Ar/Ar dating method can be extended into the time of early human life and into recorded history.

answers: NDQ_005711

answers: measuring the amount of radioactive decay

answers: NDQ_005712

answers: half-life

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: half-life

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: the decay-product of the radioactive parent isotope

answers: NDQ_005718

answers: Most radiometric methods are suitable for geological time only

answers: NDQ_005719

answers: not enough information

answers: NDQ_005720

answers: radioactive decay

answers: NDQ_005711

answers: measuring the amount of radioactive decay

answers: NDQ_005712

answers: geological time

answers: NDQ_005713

answers: a radioactive isotope with a known half-life,

answers: NDQ_005714

answers: geologists can establish the absolute age of the parent material.

answers: NDQ_005715

answers: less accurate in absolute years.

answers: NDQ_005716

answers: decay-product of the radioactive parent isotope.

answers: NDQ_005717

answers: measuring an increase in the abundance of a radiogenic isotope,

answers: NDQ_005718

answers: less accurate in absolute years.

answers: NDQ_005719

answers: Ar/Ar dating method

answers: NDQ_005720

answers: radiocarbon method,

text: Diploporus torreyoides has been identified from a single location in the Clarno Formation, the Clarno nut beds, type locality for both the formation and the species.  The nut beds are approximately  east of the unincorporated community of Clarno, Oregon and currently considered to be middle Eocene in age, based on averaging zircon fission track radiometric dating which yielded an age of 43.6 and 43.7 ± 10 million years ago and Argon–argon dating radiometric dating which yielded a 36.38 ± 1.31 to 46.8 ± 3.36 mya date.  The average of the dates resulted in an age range of 45 to 43 mya.  The beds are composed of silica and calcium carbonate cemented tuffaceous sandstones, siltstones, and conglomerates which preserve either a lake delta environment, or alternatively periodic floods and volcanic mudflows preserved with hot spring activity.  An unidentified species of Diploporus has been reported from the Sentinel Butte Formation near the town of Almont, North Dakota and the Beicegal Creek, North Dakota.  The age of the formation is based on the recovery of late Tiffanian mammals in the upper section of the formation along with the floral and palynological assemblages of the formation.

text: Diploporus torreyoides has been identified from a single location in the

text: Clarno Formation

text: , the Clarno nut beds,

text: type locality

text: for both the formation and the species.  The nut beds are approximately  east of the unincorporated community of

text: Clarno, Oregon

text: and currently considered to be middle Eocene in age, based on averaging

text: zircon fission track

text: radiometric dating

text: which yielded an age of 43.6 and 43.7 ± 10

text: million years ago

text: and

text: Argon–argon dating

text: radiometric dating

text: which yielded a 36.38 ± 1.31 to 46.8 ± 3.36 mya date.  The average of the dates resulted in an age range of 45 to 43 mya.  The beds are composed of silica and calcium carbonate cemented

text: tuff

text: aceous sandstones, siltstones, and conglomerates which preserve either a lake delta environment, or alternatively periodic floods and volcanic mudflows preserved with hot spring activity.  An unidentified species of Diploporus has been reported from the

text: Sentinel Butte Formation

text: near the town of

text: Almont, North Dakota

text: and the Beicegal Creek, North Dakota.  The age of the formation is based on the recovery of

text: late Tiffanian

text: mammals in the upper section of the formation along with the floral and

text: palynological

text: assemblages of the formation.

answers: NDQ_005711

answers: zircon fission track

answers: NDQ_005712

answers: zircon fission track

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Argon–argon dating radiometric dating

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: Argon–argon dating

answers: NDQ_005717

answers: 36.38  1.31 to 46.8  3.36 mya

answers: NDQ_005718

answers: an age range of 45 to 43 mya

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: averaging zircon fission track

answers: NDQ_005712

answers: middle Eocene

answers: NDQ_005713

answers: averaging zircon fission track radiometric dating

answers: NDQ_005714

answers: Argon–argon

answers: NDQ_005715

answers: Argon–argon

answers: NDQ_005716

answers: Argon–argon

answers: NDQ_005717

answers: 36.38

answers: NDQ_005718

answers: age range of 45 to 43 mya.

answers: NDQ_005719

answers: Argon–argon

answers: NDQ_005720

answers: Argon–argon dating radiometric dating

text: The Beds of Nogon-Tsav are considered to be the same age as the Nemegt Formation. This geologic formation has never been dated radiometrically, but the fauna present in the fossil record indicate it was probably deposited during the Maastrichtian stage, at the end of the Late Cretaceous.

text: The Beds of Nogon-Tsav are considered to be the same age as the

text: Nemegt Formation

text: . This

text: geologic formation

text: has never been

text: dated radiometrically

text: , but the

text: fauna

text: present in the fossil record indicate it was probably deposited during the

text: Maastrichtian

text: stage

text: , at the end of the

text: Late Cretaceous

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: geologic formation has never been dated

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometrically

answers: NDQ_005718

answers: has never been dated radiometrically

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: fauna present in the fossil record

answers: NDQ_005712

answers: Late Cretaceous.

answers: NDQ_005713

answers: radiometrically,

answers: NDQ_005714

answers: radiometrically,

answers: NDQ_005715

answers: The Beds of Nogon-Tsav

answers: NDQ_005716

answers: radiometrically,

answers: NDQ_005717

answers: radiometrically,

answers: NDQ_005718

answers: This geologic formation has never been dated radiometrically,

answers: NDQ_005719

answers: radiometrically,

answers: NDQ_005720

answers: radiometrically,

text: It was claimed that the writ of error was not brought within the statute of limitations, and although the writ of error was dated the tenth day of May 1884, and was noted by the clerk as having been filed on that day, it was also marked by the clerk of the circuit court of La Crosse county, as filed on the twenty-ninth day of that month. Since it was not disputed that this was the day it was filed in his office, it was held that this was the date on which the writ of error was brought.

text: It was claimed that the writ of error was not brought within the

text: statute of limitations

text: , and although the writ of error was dated the tenth day of May 1884, and was noted by the clerk as having been filed on that day, it was also marked by the clerk of the circuit court of La Crosse county, as filed on the twenty-ninth day of that month. Since it was not disputed that this was the day it was filed in his office, it was held that this was the date on which the writ of error was brought.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: the writ of error

answers: NDQ_005718

answers: statute of limitations

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: tenth day of May 1884,

answers: NDQ_005712

answers: statute of limitations,

answers: NDQ_005713

answers: tenth day of May 1884,

answers: NDQ_005714

answers: statute of limitations,

answers: NDQ_005715

answers: tenth day of May 1884,

answers: NDQ_005716

answers: tenth day of May 1884,

answers: NDQ_005717

answers: tenth day of May 1884,

answers: NDQ_005718

answers: statute of limitations,

answers: NDQ_005719

answers: tenth day of May 1884,

answers: NDQ_005720

answers: tenth day of May 1884,

text: Absolute dating in Shanga was achieved through radiocarbon testing and imported pottery. Both methods of dating present dates ranging from the 8th to 15th centuries. A total of thirteen radiocarbon dates have been processed in the site. The radiocarbon dates demonstrate that Shanga was occupied sometime between the 8th and 15th centuries. Horton points out that Shanga pottery dating has been extensively examined by archaeologists Neville Chittick, James Kirkman and Richard Wilding.

text: Absolute

text: dating

text: in Shanga was achieved through

text: radiocarbon testing

text: and imported pottery. Both methods of dating present dates ranging from the 8th to 15th centuries. A total of thirteen radiocarbon dates have been processed in the site. The radiocarbon dates demonstrate that Shanga was occupied sometime between the 8th and 15th centuries. Horton points out that Shanga pottery dating has been extensively examined by archaeologists

text: Neville Chittick

text: , James Kirkman and Richard Wilding.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: 8th to 15th centuries

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: absolute dating

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: 8th to 15th centuries.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: Absolute dating in Shanga was achieved through radiocarbon testing

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: 8th to 15th centuries.

answers: NDQ_005718

answers: dates ranging from the 8th to 15th centuries.

answers: NDQ_005719

answers: 8th to 15th centuries.

answers: NDQ_005720

answers: radiocarbon testing

text: One example is that of dating objects, using observable evidence such as tree rings for dendrochronology or carbon-14 for radiometric dating.  The observation is caused by the age of the object being dated, rather than the reverse, and the aim is to use the method for estimating dates based on new observations. The problem is whether the model used for relating known ages with observations should aim to minimise the error in the observation, or minimise the error in the date.  The two approaches will produce different results, and the difference will increase if the model is then used for extrapolation at some distance from the known results.

text: One example is that of dating objects, using observable evidence such as

text: tree

text: rings for

text: dendrochronology

text: or

text: for

text: radiometric dating

text: .  The observation is

text: cause

text: d by the age of the object being dated, rather than the reverse, and the aim is to use the method for estimating dates based on new observations. The

text: problem

text: is whether the model used for relating known ages with observations should aim to minimise the error in the observation, or minimise the error in the date.  The two approaches will produce different results, and the difference will increase if the model is then used for

text: extrapolation

text: at some distance from the known results.

answers: NDQ_005711

answers: carbon-14

answers: NDQ_005712

answers: carbon-14

answers: NDQ_005713

answers: carbon-14

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: carbon-14

answers: NDQ_005718

answers: The two approaches will produce different results

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: carbon-14

answers: NDQ_005712

answers: The observation is caused by the age of the object being dated,

answers: NDQ_005713

answers: carbon-14

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: carbon-14 for radiometric dating.

answers: NDQ_005716

answers: carbon-14 for radiometric dating.

answers: NDQ_005717

answers: The observation is caused by the age of the object being dated,

answers: NDQ_005718

answers: whether the model used for relating known ages with observations

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: carbon-14 for radiometric dating.

text: Potassium–argon dating and argon–argon dating performed on rocks from the Chao I stage have indicated an average age of 423,000 ± 100,000 years. However, anomalous chemical compositions of the dated rocks suggest that they may overestimate the true age of the volcanics. Such alteration may be the result of the inclusion of xenocrysts or K leaching. A glacial moraine system lies on Cerro del León at  altitude. One of these moraines abuts Cerro Chao, indicating that the dome must be older than the moraine and thus older than the last glaciation 11,000 years ago.

text: Potassium–argon dating

text: and

text: argon–argon dating

text: performed on rocks from the Chao I stage have indicated an average age of 423,000 ± 100,000 years. However, anomalous chemical compositions of the dated rocks suggest that they may overestimate the true age of the volcanics. Such alteration may be the result of the inclusion of

text: xenocryst

text: s or

text: K

text: leaching. A

text: glacial moraine

text: system lies on Cerro del León at  altitude. One of these moraines abuts Cerro Chao, indicating that the dome must be older than the moraine and thus older than the last glaciation 11,000 years ago.

answers: NDQ_005711

answers: Potassium–argon dating

answers: NDQ_005712

answers: argon–argon dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: argon–argon dating

answers: NDQ_005715

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: average age of 423,000  100,000 years

answers: NDQ_005718

answers: overestimate the true age of the volcanics

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: chemical compositions

answers: NDQ_005712

answers: 423,000 <unk> 100,000 years.

answers: NDQ_005713

answers: 423,000 <unk> 100,000 years.

answers: NDQ_005714

answers: 423,000 <unk> 100,000 years.

answers: NDQ_005715

answers: 423,000 <unk> 100,000 years.

answers: NDQ_005716

answers: age of 423,000 <unk> 100,000 years.

answers: NDQ_005717

answers: 423,000 <unk> 100,000 years.

answers: NDQ_005718

answers: overestimate the true age of the volcanics.

answers: NDQ_005719

answers: 423,000 <unk> 100,000 years.

answers: NDQ_005720

answers: 423,000 <unk> 100,000 years.

text: In December 2010 Professor Timothy Jull, a member of the original 1988 radiocarbon-dating team and editor of the peer-reviewed journal Radiocarbon, coauthored an article in that journal with Rachel A Freer-Waters. They examined a portion of the radiocarbon sample that was left over from the section used by the University of Arizona in 1988 for the carbon dating exercise, and were assisted by the director of the Gloria F Ross Center for Tapestry Studies. They viewed the fragment using a low magnification (~30×) stereomicroscope, as well as under high magnification (320×) viewed through both transmitted light and polarized light, and then with epifluorescence microscopy. They found "only low levels of contamination by a few cotton fibers" and no evidence that the samples actually used for measurements in the C14 dating processes were dyed, treated, or otherwise manipulated. They concluded that the radiocarbon dating had been performed on a sample of the original shroud material.

text: In December 2010 Professor

text: Timothy Jull

text: , a member of the original 1988 radiocarbon-dating team and editor of the peer-reviewed journal Radiocarbon, coauthored an article in that journal with Rachel A Freer-Waters. They examined a portion of the radiocarbon sample that was left over from the section used by the University of Arizona in 1988 for the carbon dating exercise, and were assisted by the director of the Gloria F Ross Center for Tapestry Studies. They viewed the fragment using a low magnification (~30×) stereomicroscope, as well as under high magnification (320×) viewed through both transmitted light and polarized light, and then with epifluorescence microscopy. They found "only low levels of contamination by a few cotton fibers" and no evidence that the samples actually used for measurements in the C14 dating processes were dyed, treated, or otherwise manipulated. They concluded that the radiocarbon dating had been performed on a sample of the original shroud material.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: shroud material

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: C14 dating processes were dyed, treated, or otherwise manipulated

answers: NDQ_005718

answers: contamination by a few cotton fibers

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon-dating

answers: NDQ_005712

answers: C14

answers: NDQ_005713

answers: radiocarbon-dating

answers: NDQ_005714

answers: dyed, treated, or otherwise manipulated.

answers: NDQ_005715

answers: C14

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: C14

answers: NDQ_005718

answers: dyed, treated, or otherwise manipulated.

answers: NDQ_005719

answers: carbon dating

answers: NDQ_005720

answers: C14

text: Haidomyrmex, is known from three solitary adult fossil specimens which are composed of mostly complete adult females which have been preserved as an inclusions in transparent chunk of  Burmese amber. The amber specimens entombing H. scimitarus, and H. zigrasi were recovered from deposits in Kachin State,  west of Myitkyna town in Myanmar.  In contrast, type specimen of H. cerberus was collected in the early 1900s from an unspecified location in Myanmar.  Burmese amber has been radiometrically dated using U-Pb isotopes, yielding an age of approximately 99 million years old, close to the boundary between the Aptian and Cenomanian.  The amber is suggested to have formed in a tropical environment around 5° north latitude and the resin to have been produced by either an Araucariaceae or Cupressaceae species tree.  The mandibles of Haidomyrmecini genera are unique among ants in having a movement along the vertical plane.  All other species with a trap-jaw type mandible structure show movement along the horizontal plane.  Barden and Grimaldi suggest that the mandibles may have been capable of opening up to between 140° and 180°, if 0° is a closed position with the mandible tips near the clypeus.   The resulting gape that results from the open position is nearly twice the head capsule diameter.  The long legs and antennae are both features seen in arboreal ant species, and it has been suggested that the species may have nested in preexisting cavities in trees.

text: Haidomyrmex, is known from three solitary adult fossil specimens which are composed of mostly complete adult females which have been preserved as an

text: inclusion

text: s in transparent chunk of

text: Burmese amber

text: . The

text: amber

text: specimens entombing H. scimitarus, and H. zigrasi were recovered from deposits in

text: Kachin State

text: ,  west of Myitkyna town in Myanmar.  In contrast, type specimen of H. cerberus was collected in the early 1900s from an unspecified location in Myanmar.  Burmese amber has been

text: radiometrically dated

text: using

text: U

text: Pb

text: isotopes, yielding an age of approximately 99 million years old, close to the boundary between the

text: Aptian

text: and

text: Cenomanian

text: .  The amber is suggested to have formed in a tropical environment around 5° north latitude and the resin to have been produced by either an

text: Araucariaceae

text: or

text: Cupressaceae

text: species tree.  The mandibles of Haidomyrmecini genera are unique among ants in having a movement along the vertical plane.  All other species with a trap-jaw type mandible structure show movement along the horizontal plane.  Barden and Grimaldi suggest that the mandibles may have been capable of opening up to between 140° and 180°, if 0° is a closed position with the mandible tips near the clypeus.   The resulting gape that results from the open position is nearly twice the head capsule diameter.  The long legs and antennae are both features seen in

text: arboreal

text: ant species, and it has been suggested that the species may have nested in preexisting cavities in trees.

answers: NDQ_005711

answers: radiometrically

answers: NDQ_005712

answers: U-Pb isotopes

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: U-Pb isotopes

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: Burmese amber

answers: NDQ_005717

answers: yielding an age of approximately 99 million years old

answers: NDQ_005718

answers: age of approximately 99 million years old

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: U-Pb isotopes,

answers: NDQ_005712

answers: U-Pb isotopes,

answers: NDQ_005713

answers: movement along the vertical plane.

answers: NDQ_005714

answers: U-Pb isotopes,

answers: NDQ_005715

answers: movement along the horizontal plane.

answers: NDQ_005716

answers: radiometrically dated using U-Pb isotopes,

answers: NDQ_005717

answers: U-Pb isotopes,

answers: NDQ_005718

answers: 0° is a closed position

answers: NDQ_005719

answers: arboreal

answers: NDQ_005720

answers: 140° and 180°,

text: The usual presentation of a radiocarbon date, as a specific date plus or minus an error term, obscures the fact that the true age of the object being measured may lie outside the range of dates quoted. In 1970, the British Museum radiocarbon laboratory ran weekly measurements on the same sample for six months. The results varied widely (though consistently with a normal distribution of errors in the measurements), and included multiple date ranges (of 1σ confidence) that did not overlap with each other. The extreme measurements included one with a maximum age of under 4,400 years, and another with a minimum age of over 4,500 years.

text: The usual presentation of a radiocarbon date, as a specific date plus or minus an error term, obscures the fact that the true age of the object being measured may lie outside the range of dates quoted. In 1970, the British Museum radiocarbon laboratory ran weekly measurements on the same sample for six months. The results varied widely (though consistently with a normal distribution of errors in the measurements), and included multiple date ranges (of 1σ confidence) that did not overlap with each other. The extreme measurements included one with a maximum age of under 4,400 years, and another with a minimum age of over 4,500 years.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: true age of the object being measured may lie outside the range of dates quoted

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: may lie outside the range of dates quoted

answers: NDQ_005718

answers: may lie outside the range of dates quoted

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: true age of the object being measured may lie outside the range of dates quoted.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: may lie outside the range of dates quoted.

answers: NDQ_005715

answers: 4,400 years,

answers: NDQ_005716

answers: the true age

answers: NDQ_005717

answers: The extreme measurements included one with a maximum age of under 4,400 years,

answers: NDQ_005718

answers: true age of the object being measured may lie outside the range of dates quoted.

answers: NDQ_005719

answers: 4,400 years,

answers: NDQ_005720

answers: 4,400

text: METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is a computer model developed by the University of Idaho, that uses Landsat satellite data to compute and map evapotranspiration (ET).  METRIC calculates ET as a residual of the surface energy balance, where ET is estimated by keeping account of total net short wave and long wave radiation at the vegetation or soil surface, the amount of heat conducted into soil, and the amount of heat convected into the air above the surface.  The difference in these three terms represents the amount of energy absorbed during the conversion of liquid water to vapor, which is ET. METRIC expresses near-surface temperature gradients used in heat convection as indexed functions of radiometric surface temperature, thereby eliminating the need for absolutely accurate surface temperature and the need for air-temperature measurements.

text: METRIC (Mapping EvapoTranspiration at high Resolution with Internalized Calibration) is a

text: computer model

text: developed by the

text: University of Idaho

text: , that uses

text: Landsat

text: satellite data to compute and map

text: evapotranspiration

text: (ET).  METRIC calculates ET as a residual of the surface energy balance, where ET is estimated by keeping account of total net short wave and long wave radiation at the vegetation or soil surface, the amount of heat conducted into soil, and the amount of heat convected into the air above the surface.  The difference in these three terms represents the amount of energy absorbed during the conversion of liquid water to vapor, which is ET. METRIC expresses near-surface temperature gradients used in heat convection as indexed functions of radiometric surface temperature, thereby eliminating the need for absolutely accurate surface temperature and the need for air-temperature measurements.

answers: NDQ_005711

answers: METRIC

answers: NDQ_005712

answers: METRIC

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: METRIC calculates ET as a residual

answers: NDQ_005718

answers: need for air-temperature measurements

answers: NDQ_005719

answers: METRIC

answers: NDQ_005720

answers: NDQ_005711

answers: radiometric surface temperature,

answers: NDQ_005712

answers: eliminating the need for absolutely accurate surface temperature

answers: NDQ_005713

answers: METRIC calculates ET as a residual of the surface energy balance,

answers: NDQ_005714

answers: amount of energy absorbed during the conversion of liquid water to vapor,

answers: NDQ_005715

answers: METRIC

answers: NDQ_005716

answers: energy absorbed during the conversion of liquid water to vapor,

answers: NDQ_005717

answers: conversion of liquid water to vapor,

answers: NDQ_005718

answers: absolutely accurate surface temperature and the need for air-temperature measurements.

answers: NDQ_005719

answers: METRIC

answers: NDQ_005720

answers: METRIC

text: After the award of their PhDs, they both joined the staff at Imperial College. They published their thesis work in a paper in 1951, that had a major impact on the study of Precambrian basement complexes, by showing that it was possible to understand their metamorphic and structural development as a series of discrete orogenic events that could be discerned in the field. They proposed that an older Archaean Scourian complex, had been partially reworked by a younger paleoproterozoic Laxfordian orogenic event, as shown by its effect on a set of dolerite dykes, known as the Scourie dykes. Subsequent fieldwork, metamorphic studies and radiometric dating has refined their chronology but supported their original hypothesis.

text: After the award of their PhDs, they both joined the staff at Imperial College. They published their thesis work in a paper in 1951, that had a major impact on the study of

text: Precambrian

text: basement complexes, by showing that it was possible to understand their

text: metamorphic

text: and

text: structural

text: development as a series of discrete

text: orogenic

text: events that could be discerned in the field. They proposed that an older

text: Archaean

text: Scourian complex, had been partially reworked by a younger

text: paleoproterozoic

text: Laxfordian orogenic event, as shown by its effect on a set of

text: dolerite

text: dyke

text: s, known as the Scourie dykes. Subsequent fieldwork, metamorphic studies and

text: radiometric dating

text: has refined their chronology but supported their original hypothesis.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Precambrian

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric dating has refined their chronology but supported their original hypothesis

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Subsequent fieldwork

answers: NDQ_005718

answers: original hypothesis

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric

answers: NDQ_005711

answers: fieldwork,

answers: NDQ_005712

answers: Precambrian

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: supported their original hypothesis.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Yoshinogari (吉野ヶ里 遺跡 Yoshinogari iseki) is the name of a large and complex Yayoi archaeological site in Yoshinogari and Kanzaki in Saga Prefecture, Kyūshū, Japan. According to the Yayoi chronology established by pottery seriations in the 20th century, Yoshinogari dates to between the 3rd century BC and the 3rd century AD. However, recent attempts to use absolute dating methods such as AMS radiocarbon dating have shown that the earliest Yayoi component of Yoshinogari dates to before 400 BC.

text: Yoshinogari (吉野ヶ里 遺跡 Yoshinogari iseki) is the name of a large and complex

text: Yayoi

text: archaeological site

text: in

text: Yoshinogari

text: and

text: Kanzaki

text: in

text: Saga Prefecture

text: Kyūshū

text: Japan

text: . According to the Yayoi chronology established by pottery seriations in the 20th century, Yoshinogari dates to between the 3rd century BC and the 3rd century AD. However, recent attempts to use absolute dating methods such as

text: AMS

text: radiocarbon dating

text: have shown that the earliest Yayoi component of Yoshinogari dates to before 400 BC.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: AMS radiocarbon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: AMS radiocarbon dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: AMS radiocarbon dating

answers: NDQ_005718

answers: absolute dating methods

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: AMS radiocarbon

answers: NDQ_005712

answers: absolute dating methods such as AMS radiocarbon

answers: NDQ_005713

answers: AMS radiocarbon dating

answers: NDQ_005714

answers: AMS radiocarbon dating

answers: NDQ_005715

answers: Yoshinogari

answers: NDQ_005716

answers: absolute dating

answers: NDQ_005717

answers: before 400 BC.

answers: NDQ_005718

answers: absolute

answers: NDQ_005719

answers: AMS radiocarbon dating

answers: NDQ_005720

answers: AMS radiocarbon dating

text: Measurement of radiocarbon was originally done by beta-counting devices, which counted the amount of beta radiation emitted by decaying  atoms in a sample. More recently, accelerator mass spectrometry has become the method of choice; it counts all the  atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples (as small as individual plant seeds), and gives results much more quickly. The development of radiocarbon dating has had a profound impact on archaeology. In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the "radiocarbon revolution".  Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the last ice age, and the beginning of the Neolithic and Bronze Age in different regions.

text: Measurement of radiocarbon was originally done by beta-counting devices, which counted the amount of

text: beta radiation

text: emitted by decaying  atoms in a sample. More recently,

text: accelerator mass spectrometry

text: has become the method of choice; it counts all the  atoms in the sample and not just the few that happen to decay during the measurements; it can therefore be used with much smaller samples (as small as individual plant seeds), and gives results much more quickly. The development of radiocarbon dating has had a profound impact on

text: archaeology

text: . In addition to permitting more accurate dating within archaeological sites than previous methods, it allows comparison of dates of events across great distances. Histories of archaeology often refer to its impact as the "radiocarbon revolution".  Radiocarbon dating has allowed key transitions in prehistory to be dated, such as the end of the

text: last ice age

text: , and the beginning of the

text: Neolithic

text: and

text: Bronze Age

text: in different regions.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: it counts all the atoms

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: it counts all the atoms in the sample

answers: NDQ_005715

answers: NDQ_005716

answers: beta radiation emitted

answers: NDQ_005717

answers: accelerator mass spectrometry has become the method of choice

answers: NDQ_005718

answers: can therefore be used with much smaller samples

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: decaying atoms

answers: NDQ_005712

answers: Neolithic and Bronze Age

answers: NDQ_005713

answers: accelerator mass spectrometry

answers: NDQ_005714

answers: accelerator mass spectrometry

answers: NDQ_005715

answers: accelerator mass spectrometry

answers: NDQ_005716

answers: decaying atoms

answers: NDQ_005717

answers: beta radiation emitted by decaying atoms

answers: NDQ_005718

answers: smaller samples

answers: NDQ_005719

answers: individual plant seeds),

answers: NDQ_005720

answers: accelerator mass spectrometry

text: It is important to acknowledge that radiometric dating of volcanism along hotspot traces may or may not accurately and precisely constrain the position of the plate above the underlying hotspot at the analytically produced age. However, reconstruction models for the Hawaiian set are constrained in age by the hotspot beneath Easter Island and its traces on the Pacific and Nazca plates between approximately 50 and 30 Ma, as the hotspot was beneath the spreading center during that time interval, and resulting relative plate reconstructions constrain motion of the plates relative to the hotspot. Prior to 50 Ma and since 30 Ma, reconstructions can be determined that fit virtually all existing Hawaiian set traces; the actual ages have the greatest uncertainty. Similarly, plate reconstructions relative to the Tristan set are best constrained in age by relative plate reconstructions, a fortuitous consequence of spherical plate tectonics of three or more plates.

text: It is important to acknowledge that

text: radiometric dating

text: of

text: volcanism

text: along hotspot traces may or may not accurately and precisely constrain the position of the plate above the underlying hotspot at the analytically produced age. However, reconstruction models for the Hawaiian set are constrained in age by the hotspot beneath

text: Easter Island

text: and its traces on the

text: Pacific

text: and

text: Nazca plates

text: between approximately 50 and 30 Ma, as the hotspot was beneath the

text: spreading center

text: during that time interval, and resulting relative plate reconstructions constrain motion of the plates relative to the hotspot. Prior to 50 Ma and since 30 Ma, reconstructions can be determined that fit virtually all existing Hawaiian set traces; the actual ages have the greatest uncertainty. Similarly, plate reconstructions relative to the Tristan set are best constrained in age by relative plate reconstructions, a fortuitous consequence of spherical plate tectonics of three or more plates.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: prior to 50 Ma and since 30 Ma

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: accurately and precisely constrain the position of the plate above the underlying hotspot

answers: NDQ_005719

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: hotspot traces

answers: NDQ_005712

answers: spherical plate tectonics of three or more plates.

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: 50 and 30 Ma,

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: constrain the position of the plate above the underlying hotspot

answers: NDQ_005718

answers: may or may not accurately and precisely constrain the position of the plate

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: A small bone fragment was submitted to the University of California, Riverside, for radiocarbon dating, which indicated the age of the skeleton was approximately 9,300 to 9,600 years (8,400 uncalibrated "radiocarbon years"), not the 19th century, as had originally been thought. Subsequent radiocarbon dating indicates a somewhat younger age of 8.9k to 9k cal years BP.

text: A small bone fragment was submitted to the

text: University of California, Riverside

text: , for

text: radiocarbon dating

text: , which indicated the age of the skeleton was approximately 9,300 to 9,600 years (8,400

text: uncalibrated

text: "radiocarbon years"), not the 19th century, as had originally been thought. Subsequent radiocarbon dating indicates a somewhat younger age of 8.9k to 9k cal years BP.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon is a noble gas

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: uncalibrated

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 9,300 to 9,600

answers: NDQ_005716

answers: radiocarbon dating,

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: uncalibrated

answers: NDQ_005719

answers: radiocarbon dating,

answers: NDQ_005720

answers: radiocarbon dating,

text: There is no reliable date of when Pisgah Crater last erupted. Some believe that Pisgah Volcano is the youngest vent, of four cinder cones, in the Lavic Lake volcanic field.  There may have been activity at this site as recent as 2,000 years ago; however others believe the last eruption occurred as early as 20,000 to 50,000 years ago.  It is too young for the commonly used potassium-argon dating technique usable on specimens over 100,000 years old; as the volcano is basaltic, finding a reliable source of potassium for dating purposes would be difficult anyway. No charred organic material for radiocarbon dating has been found.

text: There is no reliable date of when Pisgah Crater last erupted. Some believe that Pisgah Volcano is the youngest vent, of four cinder cones, in the

text: Lavic Lake volcanic field

text: .  There may have been activity at this site as recent as 2,000 years ago; however others believe the last eruption occurred as early as 20,000 to 50,000 years ago.  It is too young for the commonly used

text: potassium-argon dating

text: technique usable on specimens over 100,000 years old; as the volcano is basaltic, finding a reliable source of potassium for dating purposes would be difficult anyway. No charred organic material for

text: radiocarbon dating

text: has been found.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating has been found

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: no charred organic material has been found

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating measures when the organism died

answers: NDQ_005717

answers: is too young for the commonly used potassium-argon dating technique usable on specimens over 100,000 years old

answers: NDQ_005718

answers: No charred organic material for radiocarbon dating has been found

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: potassium-argon dating technique usable on specimens over 100,000 years old;

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: charred organic material

answers: NDQ_005717

answers: usable on specimens over 100,000 years old;

answers: NDQ_005718

answers: No charred organic material for radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: potassium-argon dating technique

text: Holmes's persistence finally began to pay off in 1921, when the speakers at the yearly meeting of the British Association for the Advancement of Science came to a rough consensus that Earth was a few billion years old, and that radiometric dating was credible. Holmes published The Age of the Earth, an Introduction to Geological Ideas in 1927 in which he presented a range of 1.6 to 3.0 billion years. No great push to embrace radiometric dating followed, however, and the die-hards in the geological community stubbornly resisted. They had never cared for attempts by physicists to intrude in their domain, and had successfully ignored them so far The growing weight of evidence finally tilted the balance in 1931, when the National Research Council of the US National Academy of Sciences decided to resolve the question of the age of Earth by appointing a committee to investigate. Holmes, being one of the few people on Earth who was trained in radiometric dating techniques, was a committee member, and in fact wrote most of the final report.

text: Holmes's persistence finally began to pay off in 1921, when the speakers at the yearly meeting of the

text: British Association for the Advancement of Science

text: came to a rough consensus that Earth was a few billion years old, and that radiometric dating was credible. Holmes published The Age of the Earth, an Introduction to Geological Ideas in 1927 in which he presented a range of 1.6 to 3.0 billion years. No great push to embrace radiometric dating followed, however, and the die-hards in the geological community stubbornly resisted. They had never cared for attempts by physicists to intrude in their domain, and had successfully ignored them so far The growing weight of evidence finally tilted the balance in 1931, when the

entity_name: National Research Council (United States)

text: National Research Council

text: of the US

text: National Academy of Sciences

text: decided to resolve the question of the age of Earth by appointing a committee to investigate. Holmes, being one of the few people on Earth who was trained in radiometric dating techniques, was a committee member, and in fact wrote most of the final report.

answers: NDQ_005711

answers: radioactive

answers: NDQ_005712

answers: a few billion years

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating is credible

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Holmes, being one of the few people on Earth who was trained

answers: NDQ_005718

answers: die-hards in the geological community stubbornly resisted

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: a few billion years old,

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric dating was credible.

answers: NDQ_005715

answers: Holmes's persistence finally began to pay off in 1921,

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating techniques,

answers: NDQ_005718

answers: attempts by physicists to intrude in their domain,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: The subdivisions of the Mesoproterozoic are arbitrary divisions based on time. They are not geostratigraphic or biostratigraphic units. The base of the Mesoproterozoic is defined chronometrically, in terms of years, rather than by the appearance or disappearance of some organism. This gives an illusory sense of certainty. Radiometric dating is a good tool, and gets better each decade. This creates some problems. As a practical matter, radiometric dates have an error margin of 1-2%. That sounds good, but it means that two sites, both measured to be at the exact base of the Ectasian, might differ in age by over 50 My. Since the Ectasian is only 200 My long, these differences dramatically influence its timescale. And this accounts only for random error, ignoring systematic errors.Systematic errors can be caused by extraterrestrial events, by geochemical or biochemical sorting of isotopes, and human error. Thus far, biostratigraphy has usually proved considerably more exact. In addition, a thoughtful choice of biological marker can be used as a signal to expect a whole host of ecological changes. The difference between a Changhsingian and an Induan deposit isn't just a matter of a few years. The world changed significantly at the end of the Permian.

text: The subdivisions of the Mesoproterozoic are arbitrary divisions based on time. They are not

text: geostratigraphic

text: or

text: biostratigraphic

text: units. The base of the Mesoproterozoic is defined

text: chronometrically

text: , in terms of years, rather than by the appearance or disappearance of some organism. This gives an illusory sense of certainty.

text: Radiometric dating

text: is a good tool, and gets better each decade. This creates some problems. As a practical matter, radiometric dates have an error margin of 1-2%. That sounds good, but it means that two sites, both measured to be at the exact base of the

text: Ectasian

text: , might differ in age by over 50 My. Since the Ectasian is only 200 My long, these differences dramatically influence its timescale. And this accounts only for random error, ignoring systematic errors.Systematic errors can be caused by extraterrestrial events, by geochemical or biochemical sorting of isotopes, and human error. Thus far,

text: biostratigraphy

text: has usually proved considerably more exact. In addition, a thoughtful choice of biological marker can be used as a signal to expect a whole host of

text: ecological

text: changes. The difference between a

text: Changhsingian

text: and an

text: Induan

text: deposit isn't just a matter of a few years. The world changed significantly at the end of the Permian.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: radiometric dating is a good tool

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating is a good tool

answers: NDQ_005715

answers: radiometric dating is a good tool

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dates have an error margin of

answers: NDQ_005718

answers: error margin of 1-2%

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: time.

answers: NDQ_005712

answers: random error, ignoring systematic errors.Systematic

answers: NDQ_005713

answers: radiometric dates have an error margin of 1-2%.

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: Radiometric dating

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: radiometric dates have an error margin of 1-2%.

answers: NDQ_005718

answers: error margin of 1-2%.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their absolute age, (i.e. estimated age). In geology, rock or superficial deposits, fossils and lithologies can be used to correlate one stratigraphic column with another. Prior to the discovery of radiometric dating which provided a means of absolute dating in the early 20th century, archaeologists and geologists used this technique to determine ages of materials. Though relative dating can only determine the sequential order in which a series of events occurred, not when they occur, it remains a useful technique especially in radiometric dating. Relative dating by biostratigraphy is the preferred method in paleontology, and is in some respects more accurate (Stanley, 167–69). The Law of Superposition, which states that older layers will be deeper in a site than more recent layers, was the summary outcome of 'relative dating' as observed in geology from the 17th century to the early 20th century.

text: Relative dating is the science of determining the relative order of past events (i.e., the age of an object in comparison to another), without necessarily determining their

text: absolute age

text: , (i.e. estimated age). In geology,

text: rock

text: or

text: superficial deposits

text: fossil

text: s and

text: lithologies

text: can be used to correlate one

text: stratigraphic column

text: with another. Prior to the discovery of

text: radiometric dating

text: which provided a means of

text: absolute dating

text: in the early 20th century,

text: archaeologists

text: and

text: geologist

text: s used this technique to

text: determine ages

text: of materials. Though relative dating can only determine the sequential order in which a series of events occurred, not when they occur, it remains a useful technique especially in radiometric dating. Relative dating by

text: biostratigraphy

text: is the preferred method in

text: paleontology

text: , and is in some respects more accurate (Stanley, 167–69). The

text: Law of Superposition

text: , which states that older layers will be deeper in a site than more recent layers, was the summary outcome of 'relative dating' as observed in geology from the 17th century to the early 20th century.

answers: NDQ_005711

answers: yes

answers: NDQ_005712

answers: relative dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Absolute dating

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: Absolute dating

answers: NDQ_005717

answers: relative dating can only determine the sequential order in which a series of events occurred

answers: NDQ_005718

answers: relative dating can only determine the sequential order

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiometric dating which provided a means of absolute dating

answers: NDQ_005712

answers: absolute dating

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: when they occur,

answers: NDQ_005717

answers: radiometric dating.

answers: NDQ_005718

answers: when they occur,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Dates provide a wide range of essential nutrients, and are a very good source of dietary potassium. The sugar content of ripe dates is about 80%; the remainder consists of protein, fiber, and trace elements including boron, cobalt, copper, fluorine, magnesium, manganese, selenium, and zinc.  The glycemic index for three different varieties of dates are 35.5 (khalas), 49.7 (barhi), and 30.5 (bo ma'an).

text: Dates provide a wide range of

text: essential nutrients

text: , and are a very good source of

text: diet

text: ary

text: potassium

text: . The

text: sugar

text: content of ripe dates is about 80%; the remainder consists of

text: protein

text: fiber

text: , and

text: trace elements

text: including

text: boron

text: cobalt

text: copper

text: fluorine

text: magnesium

text: manganese

text: selenium

text: , and

text: zinc

text: .  The

text: glycemic index

text: for three different varieties of dates are 35.5 (khalas), 49.7 (barhi), and 30.5 (bo ma'an).

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: boron and cobalt

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: potassium

answers: NDQ_005718

answers: glycemic index

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: trace elements

answers: NDQ_005712

answers: Dates provide a wide range of essential nutrients,

answers: NDQ_005713

answers: 80%;

answers: NDQ_005714

answers: potassium.

answers: NDQ_005715

answers: potassium.

answers: NDQ_005716

answers: potassium.

answers: NDQ_005717

answers: boron,

answers: NDQ_005718

answers: The sugar content of ripe dates is about 80%;

answers: NDQ_005719

answers: potassium.

answers: NDQ_005720

answers: zinc.

text: Because of their refractory nature and stability under diverse conditions, baddeleyite grains, along with zircon, are used for uranium-lead radiometric age determinations.

text: Because of their refractory nature and stability under diverse conditions, baddeleyite grains, along with

text: zircon

text: , are used for

text: uranium-lead

text: radiometric age

text: determinations.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: baddeleyite

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: baddeleyite grains

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: zircon decay

answers: NDQ_005717

answers: baddeleyite grains

answers: NDQ_005718

answers: stability under diverse conditions

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead

answers: NDQ_005712

answers: refractory nature and stability under diverse conditions,

answers: NDQ_005713

answers: uranium-lead

answers: NDQ_005714

answers: refractory nature and stability under diverse conditions,

answers: NDQ_005715

answers: baddeleyite grains, along with zircon,

answers: NDQ_005716

answers: uranium-lead radiometric age

answers: NDQ_005717

answers: baddeleyite grains,

answers: NDQ_005718

answers: stability under diverse conditions,

answers: NDQ_005719

answers: uranium-lead radiometric age determinations.

answers: NDQ_005720

answers: uranium-lead radiometric age determinations.

text: The difference between radiocarbon dating and OSL is that the former is used to date organic materials, while the latter is used to date minerals. Events that can be dated using OSL are, for example, the mineral's last exposure to sunlight; Mungo Man, Australia's oldest human find, was dated in this manner. It is also used for dating the deposition of geological sediments after they have been transported by air (aeolian sediments) or rivers (fluvial sediments). In archaeology, OSL dating is applied to ceramics: The dated event is the time of their last heating to a high temperature (in excess of 400 °C).

text: The difference between

text: radiocarbon dating

text: and OSL is that the former is used to date organic materials, while the latter is used to date minerals. Events that can be dated using OSL are, for example, the mineral's last exposure to sunlight;

text: Mungo Man

text: , Australia's oldest human find, was dated in this manner. It is also used for dating the deposition of geological sediments after they have been transported by air (

text: aeolian

text: sediments) or rivers (

text: fluvial

text: sediments). In archaeology, OSL dating is applied to ceramics: The dated event is the time of their last heating to a high temperature (in excess of 400 °C).

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: the former is used to date organic materials

answers: NDQ_005715

answers: radiocarbon dating

answers: NDQ_005716

answers: OSL

answers: NDQ_005717

answers: the mineral's last exposure to sunlight

answers: NDQ_005718

answers: the latter is used to date minerals

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon

answers: NDQ_005711

answers: last exposure to sunlight;

answers: NDQ_005712

answers: organic materials,

answers: NDQ_005713

answers: radiocarbon dating and OSL

answers: NDQ_005714

answers: OSL is that the former is used to date organic materials,

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: organic materials,

answers: NDQ_005717

answers: the mineral's last exposure to sunlight;

answers: NDQ_005718

answers: the former is used to date organic materials,

answers: NDQ_005719

answers: OSL

answers: NDQ_005720

answers: OSL

text: Radiocarbon dating has been used since 1946 to determine the age of organic material as old as 50,000 years. As the organism dies, the exchange of C with the environment ceases and the incorporated C decays. Given the decay of this isotope (the half-life of C is about 5,730 years), the amount of C left in the dead organism permits to calculate how long ago it died. Bomb pulse dating should be considered a special form of carbon dating. As discussed above and in the Radiolab episode, Elements (section 'Carbon'),  in bomb pulse dating the slow absorption of atmospheric C by the biosphere, can be considered as a chronometer. Starting from the pulse around the years 1963 (see figure), atmospheric radiocarbon decreased with 1% a year. So in bomb pulse dating it is the amount of C in the atmosphere that is decreasing and not the amount of C in a dead organisms, as is the case in classical radiocarbon dating. This decrease in atmospheric C can be measured in cells and tissues and has permitted scientists to determine the age of individual cells and of deceased people. These applications are very similar to the experiments conducted with pulse-chase analysis in which cellular processes are examined over time by exposing the cells to a labeled compound (pulse) and then to the same compound in an unlabeled form (chase). Radioactivity is a commonly used label in these experiments. An important difference between pulse-chase analysis and bomb pulse dating is the absence of the chase in the latter.

text: Radiocarbon dating

text: has been used since 1946 to determine the age of organic material as old as 50,000 years. As the organism dies, the exchange of C with the environment ceases and the incorporated C decays. Given the decay of this isotope (the

text: half-life

text: of C is about 5,730 years), the amount of C left in the dead organism permits to calculate how long ago it died. Bomb pulse dating should be considered a special form of carbon dating. As discussed above and in the

text: Radiolab

text: episode, Elements (section 'Carbon'),  in bomb pulse dating the slow absorption of atmospheric C by the biosphere, can be considered as a chronometer. Starting from the pulse around the years 1963 (see figure), atmospheric radiocarbon decreased with 1% a year. So in bomb pulse dating it is the amount of C in the atmosphere that is decreasing and not the amount of C in a dead organisms, as is the case in classical radiocarbon dating. This decrease in atmospheric C can be measured in cells and tissues and has permitted scientists to determine the age of individual cells and of deceased people. These applications are very similar to the experiments conducted with

text: pulse-chase analysis

text: in which cellular processes are examined over time by exposing the cells to a labeled compound (pulse) and then to the same compound in an unlabeled form (chase).

text: Radioactivity

text: is a commonly used label in these experiments. An important difference between pulse-chase analysis and bomb pulse dating is the absence of the chase in the latter.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: 50,000 years

answers: NDQ_005713

answers: the amount of C left in the dead organism permits to calculate how long ago it died

answers: NDQ_005714

answers: half-life of C is about 5,730 years

answers: NDQ_005715

answers: what is the half-life of carbon-14

answers: NDQ_005716

answers: exchange of C with the environment cease

answers: NDQ_005717

answers: the exchange of C with the environment ceases and the incorporated C decays

answers: NDQ_005718

answers: half-life of C

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: 50,000 years.

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Bomb pulse dating

answers: NDQ_005715

answers: (the half-life of C

answers: NDQ_005716

answers: exchange of C with the environment ceases and the incorporated C decays.

answers: NDQ_005717

answers: 1% a year.

answers: NDQ_005718

answers: (the half-life of C is about 5,730 years),

answers: NDQ_005719

answers: Bomb pulse dating

answers: NDQ_005720

answers: Radiocarbon dating

text: Argon–argon (or Ar/Ar) dating is a radiometric dating method invented to supersede potassium-argon (K/Ar) dating in accuracy. The older method required splitting samples into two for separate potassium and argon measurements, while the newer method requires only one rock fragment or mineral grain and uses a single measurement of argon isotopes. Ar/Ar dating relies on neutron irradiation from a nuclear reactor to convert a stable form of potassium (K) into the radioactive Ar. As long as a standard of known age is co-irradiated with unknown samples, it is possible to use a single measurement of argon isotopes to calculate the K/Ar* ratio, and thus to calculate the age of the unknown sample. Ar* refers to the radiogenic Ar, i.e. the Ar produced from radioactive decay of K. Ar* does not include atmospheric argon adsorbed to the surface or inherited through diffusion and its calculated value is derived from measuring the Ar (which is assumed to be of atmospheric origin) and assuming that Ar is found in a constant ratio to Ar in atmospheric gases.

text: Argon–argon (or Ar/Ar) dating is a

text: radiometric dating

text: method invented to supersede

text: potassium-argon (K/Ar) dating

text: in accuracy. The older method required splitting samples into two for separate potassium and argon measurements, while the newer method requires only one rock fragment or mineral grain and uses a single measurement of argon isotopes. Ar/Ar dating relies on neutron irradiation from a nuclear reactor to convert a stable form of potassium (

text: K

text: ) into the radioactive

text: Ar

text: . As long as a standard of known age is co-irradiated with unknown samples, it is possible to use a single measurement of argon isotopes to calculate the K/Ar* ratio, and thus to calculate the age of the unknown sample. Ar* refers to the radiogenic Ar, i.e. the Ar produced from radioactive decay of K. Ar* does not include atmospheric argon adsorbed to the surface or inherited through diffusion and its calculated value is derived from measuring the Ar (which is assumed to be of atmospheric origin) and assuming that Ar is found in a constant ratio to Ar in atmospheric gases.

answers: NDQ_005711

answers: Argon–argon

answers: NDQ_005712

answers: as long as a standard of known age is co-irradiated with unknown samples

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: Ar/Ar dating

answers: NDQ_005717

answers: required splitting samples into two for separate potassium and argon measurements

answers: NDQ_005718

answers: Ar* does not include atmospheric argon adsorbed to the surface

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: neutron irradiation

answers: NDQ_005712

answers: a standard of known age is co-irradiated with unknown samples,

answers: NDQ_005713

answers: Argon–argon

answers: NDQ_005714

answers: accuracy.

answers: NDQ_005715

answers: Argon–argon

answers: NDQ_005716

answers: age

answers: NDQ_005717

answers: splitting samples into two for separate potassium and argon measurements,

answers: NDQ_005718

answers: splitting samples into two for separate potassium and argon measurements,

answers: NDQ_005719

answers: Argon–argon

answers: NDQ_005720

answers: Argon–argon

text: Robert Strutt tinkered with Rutherford's helium method until 1910 and then ceased. However, Strutt's student Arthur Holmes became interested in radiometric dating and continued to work on it after everyone else had given up. Holmes focused on lead dating, because he regarded the helium method as unpromising. He performed measurements on rock samples and concluded in 1911 that the oldest (a sample from Ceylon) was about 1.6 billion years old. These calculations were not particularly trustworthy. For example, he assumed that the samples had contained only uranium and no lead when they were formed.

text: Robert Strutt

text: tinkered with Rutherford's helium method until 1910 and then ceased. However, Strutt's student

text: Arthur Holmes

text: became interested in radiometric dating and continued to work on it after everyone else had given up. Holmes focused on lead dating, because he regarded the helium method as unpromising. He performed measurements on rock samples and concluded in 1911 that the oldest (a sample from Ceylon) was about 1.6 billion years old. These calculations were not particularly trustworthy. For example, he assumed that the samples had contained only uranium and no lead when they were formed.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Strutt's student Arthur Holmes became interested in radiometric dating

answers: NDQ_005718

answers: calculations were not particularly trustworthy

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: measurements on rock samples

answers: NDQ_005712

answers: 1.6 billion years old.

answers: NDQ_005713

answers: lead dating,

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: lead dating,

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: lead

answers: NDQ_005718

answers: These calculations were not particularly trustworthy.

answers: NDQ_005719

answers: lead dating,

answers: NDQ_005720

answers: 1.6 billion years old. These calculations were not particularly trustworthy.

text: Ulteramus republicensis is known only from one fossil, the part side of the holotype, specimen number UWBM 77532, which is housed in the collections of the Burke Museum of Natural History in Seattle, Washington.  The specimen is preserved as a compression fossil in silty yellow to grayish shale, which was recovered from outcrops of the Tom Thumb Tuff member of the Klondike Mountain Formation in 1993 by Wesley Wehr.  The formation is approximately Early Eocene, Ypresian in age, being radiometrically dated as .  Ulteramus was first studied by the paleoentomologists S. Bruce Archibald from Simon Fraser University in Burnaby, British Columbia and Alexandr Rasnitsyn of the A. A. Borissiak Paleontological Institute.  Their 2015 type description of the new genus and species was published in the journal Canadian Entomologist.  The genus name Ulteramus was coined by the researchers as a combination of the Latin ramus meaning "branch" and ulter meaning "on the further side".  The specific epithet republicensis is a reference to the type locality of the species in Republic, Washington.

text: Ulteramus republicensis is known only from one fossil, the

text: part side

text: of the

text: holotype

text: , specimen number UWBM 77532, which is housed in the collections of the

entity_name: Burke Museum of Natural History and Culture

text: Burke Museum of Natural History

text: in

text: Seattle, Washington

text: .  The specimen is preserved as a

text: compression fossil

text: in silty yellow to grayish

text: shale

text: , which was recovered from outcrops of the Tom Thumb Tuff member of the

text: Klondike Mountain Formation

text: in 1993 by

text: Wesley Wehr

text: .  The formation is approximately

text: Early Eocene

text: Ypresian

text: in age, being radiometrically dated as .  Ulteramus was first studied by the paleoentomologists S. Bruce Archibald from

text: Simon Fraser University

text: in

text: Burnaby, British Columbia

text: and

text: Alexandr Rasnitsyn

text: of the

text: A. A. Borissiak Paleontological Institute

text: .  Their 2015

text: type description

text: of the new genus and species was published in the journal

text: Canadian Entomologist

text: .  The genus name Ulteramus was coined by the researchers as a combination of the

text: Latin

text: ramus meaning "branch" and ulter meaning "on the further side".  The

text: specific epithet

text: republicensis is a reference to the type locality of the species in

text: Republic, Washington

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Early Eocene

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: radiometrically dated as

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometrically dated as

answers: NDQ_005718

answers: Ypresian in age

answers: NDQ_005719

answers: radiometrically dated

answers: NDQ_005720

answers: NDQ_005711

answers: Early Eocene, Ypresian

answers: NDQ_005712

answers: Early Eocene, Ypresian

answers: NDQ_005713

answers: Early Eocene, Ypresian

answers: NDQ_005714

answers: radiometrically dated

answers: NDQ_005715

answers: Early Eocene,

answers: NDQ_005716

answers: radiometrically dated

answers: NDQ_005717

answers: radiometrically dated as.

answers: NDQ_005718

answers: Ypresian in age,

answers: NDQ_005719

answers: radiometrically dated

answers: NDQ_005720

answers: radiometrically dated

text: The play is universally dated to sometime in the first decade of the 17th century, based on all the available data. Many scholars favor the year 1605; leading Chapman scholar T. M. Parrott assigned it to the winter of 1605–6. Critics have seen the parody of incompetent justice in the play's final scene as Chapman's response to his imprisonment over the Eastward Ho scandal of 1605 — though E. K. Chambers demured on this point, suggesting that "It would be equally sound to argue that this is just the date when Chapman would have been most careful to avoid criticism of this kind." Chambers and others have given a dating range of 1603–9.

text: The play is universally dated to sometime in the first decade of the 17th century, based on all the available data. Many scholars favor the year 1605; leading Chapman scholar

text: T. M. Parrott

text: assigned it to the winter of 1605–6. Critics have seen the parody of incompetent justice in the play's final scene as Chapman's response to his imprisonment over the

text: Eastward Ho

text: scandal of 1605 — though

text: E. K. Chambers

text: demured on this point, suggesting that "It would be equally sound to argue that this is just the date when Chapman would have been most careful to avoid criticism of this kind." Chambers and others have given a dating range of 1603–9.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating works for materials of these ages

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 1605–6

answers: NDQ_005718

answers: many scholars favor the year 1605

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: all the available data.

answers: NDQ_005712

answers: 17th century,

answers: NDQ_005713

answers: 1603–9.

answers: NDQ_005714

answers: 1603–9.

answers: NDQ_005715

answers: 1603–9.

answers: NDQ_005716

answers: dated to sometime in the first decade of the 17th century,

answers: NDQ_005717

answers: 1603–9.

answers: NDQ_005718

answers: all the available data.

answers: NDQ_005719

answers: 1603–9.

answers: NDQ_005720

answers: 1603–9.

text: Morphology in archaeology, the study of shapes and forms, and their grouping into period styles remains a crucial tool, despite modern techniques like radiocarbon dating, in the identification and dating not only of works of art but all classes of archaeological artefact, including purely functional ones (ignoring the question of whether purely functional artefacts exist).  The term morphology ("study of shapes", from the Greek) is more often used for this.  Morphological analyses of many individual artefacts are used to construct typologies for different types of artefact, and by the technique of seriation a relative dating based on shape and style for a site or group of sites is achieved where scientific absolute dating techniques cannot be used, in particular where only stone, ceramic or metal artefacts or remains are available, which is often the case.  That artefacts such as pottery very often survive only in fragments makes precise knowledge of morphology even more necessary, as it is often necessary to identify and date a piece of pottery from only a few sherds.

text: Morphology in

text: archaeology

text: , the study of shapes and forms, and their grouping into period

text: styles

text: remains a crucial tool, despite modern techniques like

text: radiocarbon dating

text: , in the identification and dating not only of works of art but all classes of

text: archaeological artefact

text: , including purely functional ones (ignoring the question of whether purely functional artefacts exist).  The term morphology ("study of shapes", from the Greek) is more often used for this.  Morphological analyses of many individual artefacts are used to construct

text: typologies

text: for different types of artefact, and by the technique of

text: seriation

text: a

text: relative dating

text: based on shape and style for a site or group of sites is achieved where scientific

text: absolute dating

text: techniques cannot be used, in particular where only stone, ceramic or metal artefacts or remains are available, which is often the case.  That artefacts such as pottery very often survive only in fragments makes precise knowledge of morphology even more necessary, as it is often necessary to identify and date a piece of pottery from only a few

text: sherd

text: s.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: Morphology in archaeology

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: the study of shapes and forms

answers: NDQ_005718

answers: only stone, ceramic or metal artefacts or remains are available

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: stone, ceramic or metal artefacts or remains are available,

answers: NDQ_005713

answers: radiocarbon dating,

answers: NDQ_005714

answers: where scientific absolute dating techniques cannot be used,

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating,

answers: NDQ_005717

answers: radiocarbon dating,

answers: NDQ_005718

answers: only stone, ceramic or metal artefacts or remains are available,

answers: NDQ_005719

answers: radiocarbon dating,

answers: NDQ_005720

answers: radiocarbon dating,

text: On heating with diborane, uranium hydride produces uranium boride. With bromine at 300 °C, uranium(IV) bromide is produced. With chlorine at 250 °C, uranium(IV) chloride is produced. Hydrogen fluoride at 20 °C produces uranium(IV) fluoride. Hydrogen chloride at 300 °C produces uranium(III) chloride. Hydrogen bromide at 300 °C produces uranium(III) bromide. Hydrogen iodide at 300 °C produces uranium(III) iodide. Ammonia at 250 °C produces uranium(III) nitride. Hydrogen sulfide at 400 °C produces uranium(IV) sulfide. Oxygen at 20 °C produces triuranium octoxide. Water at 350 °C produces uranium dioxide.

text: On heating with

text: diborane

text: , uranium hydride produces

text: uranium boride

text: . With

text: bromine

text: at 300 °C,

text: uranium(IV) bromide

text: is produced. With

text: chlorine

text: at 250 °C,

text: uranium(IV) chloride

text: is produced.

text: Hydrogen fluoride

text: at 20 °C produces

text: uranium(IV) fluoride

text: Hydrogen chloride

text: at 300 °C produces

text: uranium(III) chloride

text: Hydrogen bromide

text: at 300 °C produces

text: uranium(III) bromide

text: Hydrogen iodide

text: at 300 °C produces

text: uranium(III) iodide

text: Ammonia

text: at 250 °C produces

text: uranium(III) nitride

text: Hydrogen sulfide

text: at 400 °C produces

text: uranium(IV) sulfide

text: Oxygen

text: at 20 °C produces

text: triuranium octoxide

text: . Water at 350 °C produces

text: uranium dioxide

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: triuranium octoxide

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: triuranium octoxide

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: triuranium octoxide

answers: NDQ_005717

answers: triuranium octoxide

answers: NDQ_005718

answers: water at 350 °C

answers: NDQ_005719

answers: Which of the following is not useful for very young materials: potassium-argon and uranium-lead

answers: NDQ_005720

answers: NDQ_005711

answers: heating

answers: NDQ_005712

answers: uranium hydride produces uranium boride.

answers: NDQ_005713

answers: uranium hydride produces uranium boride.

answers: NDQ_005714

answers: uranium hydride produces uranium boride.

answers: NDQ_005715

answers: uranium(III) iodide.

answers: NDQ_005716

answers: uranium hydride produces uranium boride.

answers: NDQ_005717

answers: uranium dioxide.

answers: NDQ_005718

answers: uranium hydride produces uranium boride.

answers: NDQ_005719

answers: diborane,

answers: NDQ_005720

answers: diborane,

text: Phytoliths are composed mainly of noncrystalline silicon dioxide, and about 4% to 9% of their mass is water. Carbon, nitrogen, and other major nutrient elements comprise less than 5%, and commonly less than 1%, of phytolith material by mass. These elements are present in the living cells in which the silica concretions form, so traces are retained in the phytoliths. Such immobilised elements, in particular carbon, are valuable in that they permit radiometric dating in reconstructing past vegetation patterns.The silica in phytoliths has a refractive index ranging from 1.41 to 1.47, and a specific gravity from 1.5 to 2.3. Phytoliths may be colorless, light brown, or opaque; most are transparent. Phytoliths exist in various three-dimensional shapes, some of which are specific to plant families, genera or species.

text: Phytoliths are composed mainly of noncrystalline silicon dioxide, and about 4% to 9% of their mass is water. Carbon, nitrogen, and other major nutrient elements comprise less than 5%, and commonly less than 1%, of phytolith material by mass. These elements are present in the living cells in which the silica concretions form, so traces are retained in the phytoliths. Such immobilised elements, in particular carbon, are valuable in that they permit

text: radiometric dating

text: in reconstructing past vegetation patterns.The silica in phytoliths has a

text: refractive index

text: ranging from 1.41 to 1.47, and a

text: specific gravity

text: from 1.5 to 2.3. Phytoliths may be colorless, light brown, or opaque; most are transparent. Phytoliths exist in various three-dimensional shapes, some of which are specific to plant

text: families

text: genera

text: or

text: species

answers: NDQ_005711

answers: carbon

answers: NDQ_005712

answers: carbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating in reconstructing past vegetation patterns

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: carbon are valuable in that they permit radiometric dating in reconstructing past vegetation patterns

answers: NDQ_005718

answers: about 4% to 9% of their mass is water

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: immobilised elements,

answers: NDQ_005712

answers: immobilised elements,

answers: NDQ_005713

answers: carbon,

answers: NDQ_005714

answers: reconstructing past vegetation patterns.The

answers: NDQ_005715

answers: 2.3.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: carbon,

answers: NDQ_005718

answers: reconstructing past vegetation patterns.The

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Various radiometric dates have been obtained for the Ouki paleolake from tufa, wood and fossils of Bulimulidae and Littoridina, mostly within the basin of Lake Poopo. There is noticeable disagreement between radiometric dates obtained by uranium-thorium dating and dates obtained by radiocarbon dating. The former yield ages ranging between 120,000 and 98,000 years ago. The latter produce ages between 45,200 and 28,200 years ago. Radiocarbon dates of such old samples can easily suffer from contamination by modern carbon, creating spuriously young ages. The uranium-thorium dates range between 96,740 ±5,560 and 125,990 ± 9,580 years ago. The exact lake level history is poorly known, but between 115,000 and 100,000 years ago the water was higher than . Some lake level changes coincide with cold periods in the North Atlantic. Alternatively, if radiocarbon dates of 44,609 ± 927 to 33,422 ± 1937 are attributed to Ouki, sediments in the Uyuni basin attributed to Lake Minchin would instead belong to Ouki.

text: Various radiometric dates have been obtained for the Ouki paleolake from tufa, wood and fossils of

text: Bulimulidae

text: and

text: Littoridina

text: , mostly within the basin of Lake Poopo. There is noticeable disagreement between

text: radiometric

text: dates obtained by

text: uranium-thorium dating

text: and dates obtained by

text: radiocarbon

text: dating. The former yield ages ranging between 120,000 and 98,000 years ago. The latter produce ages between 45,200 and 28,200 years ago. Radiocarbon dates of such old samples can easily suffer from contamination by modern carbon, creating spuriously young ages. The uranium-thorium dates range between 96,740 ±5,560 and 125,990 ± 9,580 years ago. The exact lake level history is poorly known, but between 115,000 and 100,000 years ago the water was higher than . Some lake level changes coincide with cold periods in the

text: North Atlantic

text: . Alternatively, if radiocarbon dates of 44,609 ± 927 to 33,422 ± 1937 are attributed to Ouki, sediments in the Uyuni basin attributed to Lake Minchin would instead belong to Ouki.

answers: NDQ_005711

answers: radiocarbon dating

answers: NDQ_005712

answers: uranium-thorium dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Radiocarbon dates of such old samples can easily suffer from contamination by modern carbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: uranium-thorium dating

answers: NDQ_005717

answers: uranium-thorium

answers: NDQ_005718

answers: The exact lake level history is poorly known

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: uranium-thorium dating and dates obtained by radiocarbon dating.

answers: NDQ_005712

answers: Radiocarbon dates of such old samples can easily suffer from contamination by modern carbon,

answers: NDQ_005713

answers: radiocarbon dating.

answers: NDQ_005714

answers: Radiocarbon dates of such old samples can easily suffer from contamination by modern carbon,

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: Radiocarbon dates of such old samples can easily suffer from contamination by modern carbon,

answers: NDQ_005717

answers: 125,990 <unk> 9,580 years ago.

answers: NDQ_005718

answers: contamination by modern carbon, creating spuriously young ages.

answers: NDQ_005719

answers: uranium-thorium dating and dates obtained by radiocarbon dating.

answers: NDQ_005720

answers: uranium-thorium dating

text: A  thick lateral layer between the (meta)sedimentary Gunflint Iron Formation and overlying Rove Formation, and between the Biwabik Iron Formation and overlying Virginia Formation has evidence that the layer contains hypervelocity impact ejecta. Radiometric dating reveals that this layer was deposited between 1,878 and 1,836 million years ago. The Sudbury Impact event – which occurred  to the east 1,850 ± 1 million years ago – is the likely ejecta source, making these the oldest ejecta linked to a specific impact. Additional evidence indicates a  diameter meteorite collided with earth in the current-day vicinity of Sudbury, Ontario, Canada. The meteorite vaporized and created a  wide crater. Earthquakes shattered the ground hundreds of kilometers away and within seconds ejecta (cloud of ash, rock fragments, gases and droplets of molten rock) began to spread around the globe. It is estimated that at ground zero the earthquake would have registered 10.2 on the Richter magnitude scale.

text: A  thick lateral layer between the (meta)sedimentary Gunflint Iron Formation and overlying Rove Formation, and between the Biwabik Iron Formation and overlying Virginia Formation has evidence that the layer contains

text: hypervelocity

text: impact ejecta

text: Radiometric dating

text: reveals that this layer was deposited between 1,878 and 1,836 million years ago. The

text: Sudbury Impact

text: event – which occurred  to the east 1,850 ± 1 million years ago – is the likely ejecta source, making these the oldest ejecta linked to a specific impact. Additional evidence indicates a  diameter meteorite collided with earth in the current-day vicinity of Sudbury, Ontario, Canada. The meteorite vaporized and created a  wide crater. Earthquakes shattered the ground hundreds of kilometers away and within seconds ejecta (cloud of ash, rock fragments, gases and droplets of molten rock) began to spread around the globe. It is estimated that at ground zero the earthquake would have registered 10.2 on the

text: Richter magnitude scale

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: ejecta

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: How long does the half-life of carbon-14 decay?

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: this layer was deposited between 1,878 and 1,836 million years ago

answers: NDQ_005718

answers: radiometric dating reveals that this layer was deposited between

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: deposited between 1,878 and 1,836 million years ago.

answers: NDQ_005712

answers: between 1,878 and 1,836 million years ago.

answers: NDQ_005713

answers: 1,878 and 1,836 million years ago.

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: 1,878 and 1,836 million years ago.

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: between 1,878 and 1,836 million years ago.

answers: NDQ_005718

answers: between 1,878 and 1,836 million years ago.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: The earliest known species is P. lujiatunensis, found in the lowest beds of the Yixian Formation. Over 200 specimens attributed to this genus have been recovered from these and other beds of the Yixian, the age of which is the subject of much debate. Although many early studies using radiometric dating put the Yixian in the Jurassic Period, tens of millions of years outside of the expected temporal range of Psittacosaurus, most recent work dates it to the Early Cretaceous. Using argon-argon dating, a team of Chinese scientists dated the lowest beds in the formation to about 128 mya, and the highest to approximately 122 mya. A more recent Chinese study, using uranium-lead dating, suggests that the lower beds are younger, approximately 123.2 mya, while agreeing with an age of 122 mya for the upper beds.

text: The earliest known species is P. lujiatunensis, found in the lowest beds of the Yixian Formation. Over 200 specimens attributed to this genus have been recovered from these and other beds of the Yixian, the age of which is the subject of much debate. Although many early studies using

text: radiometric dating

text: put the Yixian in the

text: Jurassic Period

text: , tens of millions of years outside of the expected temporal range of Psittacosaurus, most recent work dates it to the Early Cretaceous. Using

text: argon-argon dating

text: , a team of Chinese scientists dated the lowest

text: beds

text: in the formation to about 128 mya, and the highest to approximately 122 mya. A more recent Chinese study, using

text: uranium-lead dating

text: , suggests that the lower beds are younger, approximately 123.2 mya, while agreeing with an age of 122 mya for the upper beds.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: argon-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the lowest beds in the formation to about 128 mya, and the highest to approximately 122 mya

answers: NDQ_005718

answers: age of which is the subject of much debate

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: argon-argon

answers: NDQ_005712

answers: argon-argon

answers: NDQ_005713

answers: argon-argon dating,

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: argon-argon

answers: NDQ_005716

answers: argon-argon

answers: NDQ_005717

answers: argon-argon

answers: NDQ_005718

answers: tens of millions of years outside of the expected temporal range

answers: NDQ_005719

answers: argon-argon

answers: NDQ_005720

answers: 123.2 mya,

text: The date of eruption that Hodge calculated using the potassium-argon method was 25 million to 27 million years ago. This predates the earliest estimates of human presence in North America (see Settlement of the Americas) and even the earliest known humans (see Archaic Homo sapiens).

text: The date of eruption that Hodge calculated using the

text: potassium-argon method

text: was

text: 25 million to 27 million years ago

text: . This predates the earliest estimates of human presence in North America (see

text: Settlement of the Americas

text: ) and even the earliest known humans (see

text: Archaic Homo sapiens

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 25 million to 27 million years ago

answers: NDQ_005718

answers: predates the earliest estimates

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 25 million to 27 million years ago.

answers: NDQ_005713

answers: potassium-argon method was 25 million to 27 million years ago.

answers: NDQ_005714

answers: earliest estimates of human presence in North America

answers: NDQ_005715

answers: 25 million to 27 million years ago.

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 25 million to 27 million years ago.

answers: NDQ_005718

answers: predates the earliest estimates of human presence in North America

answers: NDQ_005719

answers: potassium-argon method was 25 million to 27 million years ago.

answers: NDQ_005720

answers: potassium-argon

text: The next major advance in understanding reversals came when techniques for radiometric dating were developed in the 1950s. Allan Cox and Richard Doell, at the United States Geological Survey, wanted to know whether reversals occurred at regular intervals, and invited the geochronologist Brent Dalrymple to join their group. They produced the first magnetic-polarity time scale in 1959. As they accumulated data, they continued to refine this scale in competition with Don Tarling and Ian McDougall at the Australian National University. A group led by Neil Opdyke at the Lamont-Doherty Geological Observatory showed that the same pattern of reversals was recorded in sediments from deep-sea cores.

text: The next major advance in understanding reversals came when techniques for

text: radiometric dating

text: were developed in the 1950s.

text: Allan Cox

text: and

text: Richard Doell

text: , at the

text: United States Geological Survey

text: , wanted to know whether reversals occurred at regular intervals, and invited the geochronologist

text: Brent Dalrymple

text: to join their group. They produced the first magnetic-polarity time scale in 1959. As they accumulated data, they continued to refine this scale in competition with

text: Don Tarling

text: and

text: Ian McDougall

text: at the

text: Australian National University

text: . A group led by

text: Neil Opdyke

text: at the

text: Lamont-Doherty Geological Observatory

text: showed that the same pattern of reversals was recorded in sediments from deep-sea cores.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: deep-sea cores

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Allan Cox and Richard Doell, at the United States Geological Survey

answers: NDQ_005718

answers: reversals occurred at regular intervals

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: NDQ_005711

answers: magnetic-polarity time scale

answers: NDQ_005712

answers: deep-sea cores.

answers: NDQ_005713

answers: radiometric dating were developed in the 1950s.

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: 1959.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: reversals occurred at regular intervals,

answers: NDQ_005718

answers: reversals occurred at regular intervals,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Nemegtomaia was discovered in the Nemegt Formation of southwestern Mongolia. Many genera of oviraptorosaur are known from this formation, and may have been ecologically divided. This geologic formation has never been dated radiometrically, but the fauna present in the fossil record indicate it was probably deposited during the early Maastrichtian stage, at the end of the Late Cretaceous about 70 million years ago. The rock facies of the Nemegt Formation suggest the presence of stream and river channels, mudflats, and shallow lakes. Such large river channels and soil deposits are evidence of a far more humid climate than those found in the older Barun Goyot and Djadochta formations. However, caliche deposits indicate at least periodic droughts occurred. Sediment was deposited in the channels and floodplains of large rivers.

text: Nemegtomaia was discovered in the Nemegt Formation of southwestern Mongolia. Many genera of oviraptorosaur are known from this formation, and may have been ecologically divided. This

text: geologic formation

text: has never been

text: dated radiometrically

text: , but the

text: fauna

text: present in the fossil record indicate it was probably deposited during the early

text: Maastrichtian

text: stage, at the end of the

text: Late Cretaceous

text: about 70 million years ago. The rock

text: facies

text: of the Nemegt Formation suggest the presence of stream and river channels, mudflats, and shallow lakes. Such large river channels and soil deposits are evidence of a far more humid climate than those found in the older

text: Barun Goyot

text: and

text: Djadochta

text: formations. However,

text: caliche

text: deposits indicate at least periodic droughts occurred. Sediment was deposited in the channels and floodplains of large rivers.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: geologic formation has never been dated

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: has never been dated radiometrically

answers: NDQ_005718

answers: has never been dated radiometrically

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: fauna present in the fossil record

answers: NDQ_005712

answers: Late Cretaceous about 70 million years ago.

answers: NDQ_005713

answers: 70 million years ago.

answers: NDQ_005714

answers: radiometrically,

answers: NDQ_005715

answers: Nemegtomaia was discovered in the Nemegt Formation

answers: NDQ_005716

answers: radiometrically,

answers: NDQ_005717

answers: This geologic formation has never been dated radiometrically,

answers: NDQ_005718

answers: periodic droughts

answers: NDQ_005719

answers: radiometrically,

answers: NDQ_005720

answers: radiometrically,

text: John H. Reynolds was born  in Cambridge, Massachusetts, United States.  He studied first at Harvard University and, after serving in the Navy during World War II, at the University of Chicago.  There, he was influenced by his Ph.D. thesis advisor Mark Inghram and by two other famous physicists, Harold Urey and Enrico Fermi. He specialized in mass spectrometry and utilized this method to determine isotope ratios needed for the radiometric dating of geologically and cosmologically relevant samples. In 1950 he was appointed as professor to the University of California, Berkeley where he continued his research on isotope ratios in meteorites, leading to the discovery in 1960 that the Richardton meteorite and other meteorites had an excess of xenon-129, thought to be a result of the beta decay of iodine-129 in the early solar system.  His improvement of potassium-argon dating was adopted by several institutions.

text: John H. Reynolds was born  in

text: Cambridge

text: Massachusetts

text: , United States.  He studied first at

text: Harvard University

text: and, after serving in the Navy during

text: World War II

text: , at the

text: University of Chicago

text: .  There, he was influenced by his

text: Ph.D.

text: thesis advisor

text: Mark Inghram

text: and by two other famous

text: physicists

text: Harold Urey

text: and

text: Enrico Fermi

text: . He specialized in

text: mass spectrometry

text: and utilized this method to determine isotope ratios needed for the

text: radiometric dating

text: of geologically and cosmologically relevant samples. In 1950 he was appointed as professor to the

text: University of California, Berkeley

text: where he continued his research on isotope ratios in meteorites, leading to the discovery in 1960 that the

text: Richardton meteorite

text: and other meteorites had an excess of

text: xenon

text: -129, thought to be a result of the beta decay of

text: in the early

text: solar system

text: .  His improvement of

text: potassium-argon dating

text: was adopted by several institutions.

answers: NDQ_005711

answers: mass spectrometry

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: isotope ratios

answers: NDQ_005716

answers: potassium-argon dating

answers: NDQ_005717

answers: His improvement

answers: NDQ_005718

answers: beta decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: mass spectrometry

answers: NDQ_005712

answers: geologically and cosmologically relevant samples.

answers: NDQ_005713

answers: mass spectrometry

answers: NDQ_005714

answers: radiometric dating of geologically and cosmologically relevant samples.

answers: NDQ_005715

answers: beta decay of iodine-129

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: His improvement

answers: NDQ_005718

answers: beta decay of iodine-129

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: potassium-argon

text: Sierra de Gorbea is a large lava field in the Chilean Andes that has been dated 4.7±0.5 Ma and 5.2±0.5 Ma by potassium argon dating. The lavas are dacitic to basaltic andesite with rhyolitic inclusions and no vent is evident.

text: Sierra de Gorbea is a large

text: lava field

text: in the

text: Chile

text: an

text: Andes

text: that has been dated 4.7±0.5 Ma and 5.2±0.5 Ma by

text: potassium argon dating

text: . The lavas are

text: dacitic

text: to

text: basaltic andesite

text: with

text: rhyolitic

text: inclusions and no vent is evident.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 4.7 0.5 Ma

answers: NDQ_005718

answers: no vent is evident

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium argon

answers: NDQ_005712

answers: potassium argon

answers: NDQ_005713

answers: potassium argon

answers: NDQ_005714

answers: potassium argon

answers: NDQ_005715

answers: potassium argon

answers: NDQ_005716

answers: potassium argon

answers: NDQ_005717

answers: 4.7<unk>0.5 Ma and 5.2<unk>0.5 Ma

answers: NDQ_005718

answers: no vent is evident.

answers: NDQ_005719

answers: potassium argon

answers: NDQ_005720

answers: potassium argon

text: The RATE project (Radioisotopes and the Age of The Earth) was a research project conducted by the Creation Research Society and the Institute for Creation Research between 1997 and 2005 to assess the validity of radiometric dating and other dating techniques in the light of the doctrine of a recent creation. It was funded by $250,000 from the Institute for Creation Research and over $1 million in donations.

text: The RATE project (Radioisotopes and the Age of The Earth) was a research project conducted by the

text: Creation Research Society

text: and the

text: Institute for Creation Research

text: between 1997 and 2005 to assess the validity of radiometric dating and other dating techniques in the light of the doctrine of a recent creation. It was funded by $250,000 from the Institute for Creation Research and over $1 million in donations.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: recent creation

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive isotope

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating and other dating techniques

answers: NDQ_005718

answers: validity

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: (Radioisotopes

answers: NDQ_005712

answers: recent creation.

answers: NDQ_005713

answers: The RATE project

answers: NDQ_005714

answers: doctrine of a recent creation.

answers: NDQ_005715

answers: The RATE project

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: doctrine of a recent creation.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Thomas Edvard "Tom" Krogh, FRSC (1936 – April 29, 2008) was a geochronologist and a former curator for the Royal Ontario Museum. He revolutionized the technique of radiometric uranium-lead dating with the development of new laboratory procedures and analytical methodologies. His discoveries have yielded an unprecedented level of precision in the dating of Precambrian rocks. Krogh's techniques have become the international de facto standard. The application of these techniques has provided a detailed understanding of the evolution of the Earth's Precambrian shield areas.

text: Thomas Edvard "Tom" Krogh,

text: FRSC

text: (1936 – April 29, 2008) was a

text: geochronologist

text: and a former

text: curator

text: for the

text: Royal Ontario Museum

text: . He revolutionized the technique of

text: radiometric

text: uranium-lead dating

text: with the development of new laboratory procedures and analytical methodologies. His discoveries have yielded an unprecedented level of precision in the dating of

text: Precambrian

text: rocks. Krogh's techniques have become the international de facto standard. The application of these techniques has provided a detailed understanding of the evolution of the Earth's Precambrian shield areas.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: uranium-lead

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: uranium-lead dating

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Krogh's techniques have become the international de facto standard

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: uranium-lead dating

answers: NDQ_005712

answers: Precambrian

answers: NDQ_005713

answers: uranium-lead dating

answers: NDQ_005714

answers: precision

answers: NDQ_005715

answers: Thomas Edvard "Tom" Krogh,

answers: NDQ_005716

answers: radiometric uranium-lead dating

answers: NDQ_005717

answers: radiometric uranium-lead

answers: NDQ_005718

answers: precision

answers: NDQ_005719

answers: Precambrian

answers: NDQ_005720

answers: radiometric uranium-lead dating

text: Minze Stuiver was born in Vlagtwedde, the Netherlands, in 1929.  As a boy he narrowly missed being taken into German forced labor toward the end of the Second World War, but, because he was away delivering milk by bicycle, he escaped the round-up that took most of the young men and older boys from the village.  His secondary school education was disrupted by the war when the school was occupied by German soldiers and air raids interrupted classes in makeshift rooms. After the war he went to the University of Groningen where he studied physics, mathematics and astronomy, focusing on nuclear physics.  After graduation he joined the biophysics group led by the pre-eminent researcher Hessel de Vries and received a Ph.D. in Biophysics in 1958 with a thesis on the Biophysics of the Sense of Smell.  Shortly thereafter he began working in the rapidly developing field of radiocarbon dating with de Vries, who found variations in the concentration of radiocarbon in the atmosphere which challenged the assumptions of the radiocarbon dating method.  In 1959, together with his wife, Anneke, Minze went to Yale University for a one year fellowship position but was called back to Groningen to take over as director of the radiocarbon facility when De Vries died.  However Minze chose to remain in the United States at the Geochrometric Laboratory at Yale University.   There he developed high precision methods in radiocarbon that enabled him, along with Hans Suess, to verify De Vries’ “wiggly” nature of the atmospheric concentration of radiocarbon in the past from tree-rings.  Stuiver and Suess created one of the first curves for calibration of radiocarbon dates.   In 1969 Minze moved to the newly founded Quaternary Research Center at the University of Washington (UW) in Seattle.  There he built the Quaternary Isotope Lab with a lead-lined room 30 feet below ground to shield the hand-built gas counters from detecting spurious events due to cosmic rays.

text: Minze Stuiver was born in Vlagtwedde, the Netherlands, in 1929.  As a boy he narrowly missed being taken into German forced labor toward the end of the Second World War, but, because he was away delivering milk by bicycle, he escaped the round-up that took most of the young men and older boys from the village.  His secondary school education was disrupted by the war when the school was occupied by German soldiers and air raids interrupted classes in makeshift rooms. After the war he went to the University of Groningen where he studied physics, mathematics and astronomy, focusing on nuclear physics.  After graduation he joined the biophysics group led by the pre-eminent researcher

text: Hessel de Vries

text: and received a Ph.D. in Biophysics in 1958 with a thesis on the Biophysics of the Sense of Smell.  Shortly thereafter he began working in the rapidly developing field of radiocarbon dating with de Vries, who found variations in the concentration of radiocarbon in the atmosphere which challenged the assumptions of the radiocarbon dating method.  In 1959, together with his wife, Anneke, Minze went to Yale University for a one year fellowship position but was called back to Groningen to take over as director of the radiocarbon facility when De Vries died.  However Minze chose to remain in the United States at the Geochrometric Laboratory at Yale University.   There he developed high precision methods in radiocarbon that enabled him, along with

text: Hans Suess

text: , to verify De Vries’ “wiggly” nature of the atmospheric concentration of radiocarbon in the past from tree-rings.  Stuiver and Suess created one of the first curves for

text: calibration of radiocarbon dates

text: .   In 1969 Minze moved to the newly founded Quaternary Research Center at the University of Washington (UW) in Seattle.  There he built the Quaternary Isotope Lab with a lead-lined room 30 feet below ground to shield the hand-built gas counters from detecting spurious events due to

text: cosmic rays

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: How is radiocarbon dating used?

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: How long does the half-life of carbon-14 decay to carbon-12?

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: Minze and Suess created one of the first curves for calibration of radiocarbon dates

answers: NDQ_005718

answers: variations in the concentration of radiocarbon in the atmosphere

answers: NDQ_005719

answers: Which of the following is not useful for very young materials: potassium-argon or uranium-lead?

answers: NDQ_005720

answers: How many years did Minze Stuiver work in the rapidly developing field of radiocarbon dating?

answers: NDQ_005711

answers: tree-rings.

answers: NDQ_005712

answers: tree-rings.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: variations in the concentration of radiocarbon in the atmosphere

answers: NDQ_005715

answers: “wiggly” nature of the atmospheric concentration of radiocarbon

answers: NDQ_005716

answers: tree-rings.

answers: NDQ_005717

answers: high precision methods in radiocarbon

answers: NDQ_005718

answers: detecting spurious events due to cosmic rays.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating method.

text: Wizards Beach Man was found in 1978 at Wizards Beach on Pyramid Lake, about 100 miles (160km) to the northeast from Spirit Cave. Radiocarbon dating has established that he lived more than 9,200 years ago.

text: Wizards Beach Man was found in 1978 at Wizards Beach on

text: Pyramid Lake

text: , about 100 miles (160km) to the northeast from Spirit Cave. Radiocarbon dating has established that he lived more than 9,200 years ago.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon

answers: NDQ_005718

answers: radiocarbon dating has established that he lived more than 9,200 years

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon dating has established that he lived more than 9,200 years ago.

answers: NDQ_005715

answers: Wizards Beach Man was found in 1978 at Wizards Beach on Pyramid Lake,

answers: NDQ_005716

answers: Radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon dating has established that he lived more than 9,200 years ago.

answers: NDQ_005718

answers: Radiocarbon dating has established that he lived more than 9,200 years ago.

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: Frink and others have published multiple studies demonstrating that OCR dates can correlate well with radiocarbon dates (see list of published references provided below).  Fullen's study of  the Sarah Peralta site in Louisiana  found that the OCR method served as an effective means of inferring time at the site in the absence of radiometrically dateable charcoal.  He concludes that whereas debate remains concerning the OCR procedure, "the well-corroborated dates that the LSU Museum of Natural Science has had returned on material processed with OCR and conventional radiocarbon dating...the dates returned on material from Zone 3 will be considered accurate until such time that OCR dating is proven invalid." (ibid. p. 65)

text: Frink and others have published multiple studies demonstrating that OCR dates can correlate well with

text: radiocarbon date

text: s (see list of published references provided below).  Fullen's study of  the Sarah Peralta site in Louisiana  found that the OCR method served as an effective means of inferring time at the site in the absence of radiometrically dateable charcoal.  He concludes that whereas debate remains concerning the OCR procedure, "the well-corroborated dates that the LSU Museum of Natural Science has had returned on material processed with OCR and conventional radiocarbon dating...the dates returned on material from Zone 3 will be considered accurate until such time that OCR dating is proven invalid." (ibid. p. 65)

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: OCR

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: OCR

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: ibid. p. 65

answers: NDQ_005718

answers: lack of radiometrically dateable charcoal

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Zone 3

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiometrically dateable charcoal.

answers: NDQ_005715

answers: OCR dates can correlate well with radiocarbon

answers: NDQ_005716

answers: radiometrically dateable charcoal.

answers: NDQ_005717

answers: OCR dates can correlate well with radiocarbon dates

answers: NDQ_005718

answers: radiometrically dateable charcoal.

answers: NDQ_005719

answers: OCR dates can correlate well with radiocarbon dates

answers: NDQ_005720

answers: OCR dates can correlate well with radiocarbon dates

text: In archaeology a chopping tool is a stone tool.  Stone tools have been dated using scientific dating such as Carbon 14 dating and Potassium argon dating. Stone tools have been found to be almost 2 million years old. Chopping tools have been found to be about 2 million years old as well.  The oldest object in the British Museum is a Chopping Tool. It was found in the Olduvai Gorge in Tanzania. Since Chopping tools are a sub category of stone tools we can see how these tools have developed over time.

text: In

text: archaeology

text: a chopping tool is a stone tool.  Stone tools have been dated using scientific dating such as Carbon 14 dating and Potassium argon dating. Stone tools have been found to be almost 2 million years old. Chopping tools have been found to be about 2 million years old as well.  The oldest object in the British Museum is a Chopping Tool. It was found in the

text: Olduvai Gorge

text: in Tanzania. Since Chopping tools are a sub category of stone tools we can see how these tools have developed over time.

answers: NDQ_005711

answers: Carbon 14

answers: NDQ_005712

answers: carbon 14 is a noble gas

answers: NDQ_005713

answers: How is carbon 14 dated?

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: how long does carbon-14 decay?

answers: NDQ_005716

answers: Carbon 14 dating

answers: NDQ_005717

answers: how old is a stone tool

answers: NDQ_005718

answers: Carbon 14 dating

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: Carbon 14 dating and Potassium argon dating.

answers: NDQ_005712

answers: Carbon 14 dating and Potassium argon dating.

answers: NDQ_005713

answers: Carbon 14 dating and Potassium argon dating.

answers: NDQ_005714

answers: Carbon 14 dating and Potassium argon dating.

answers: NDQ_005715

answers: Carbon 14

answers: NDQ_005716

answers: Carbon 14 dating

answers: NDQ_005717

answers: Carbon 14 dating

answers: NDQ_005718

answers: 2 million years old.

answers: NDQ_005719

answers: Carbon 14

answers: NDQ_005720

answers: Carbon 14 dating and Potassium argon dating.

text: The second phase from 19 to 28 feet deep contained the Levalloiso-Mousterian flints dated from 65 to 40 kya with current dating techniques suggest these finds are closely dated from 73 to 43 kya. At the depth of 23 feet  a modern human mandible was discovered which date between 73 and 65 kya.

text: The second phase from 19 to 28 feet deep contained the Levalloiso-Mousterian flints dated from 65 to 40 kya with current dating techniques suggest these finds are closely dated from 73 to 43 kya. At the depth of 23 feet  a modern human mandible was discovered which date between 73 and 65 kya.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 73 to 43 kya

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: current dating techniques

answers: NDQ_005712

answers: 73 to 43 kya.

answers: NDQ_005713

answers: 73 to 43 kya.

answers: NDQ_005714

answers: 73 to 43 kya.

answers: NDQ_005715

answers: 65 to 40 kya

answers: NDQ_005716

answers: 73 to 43 kya.

answers: NDQ_005717

answers: 73 to 43 kya.

answers: NDQ_005718

answers: closely dated from 73 to 43 kya.

answers: NDQ_005719

answers: 65 to 40 kya

answers: NDQ_005720

answers: 73 to 43 kya.

text: The age for the Okanagan Highland locations is, in general, Early Eocene, with the sites that have current uranium-lead or argon–argon radiometric dates being of Ypresian age, while the undated sites or those given older dates being possibly slightly younger and Lutetian in age.

text: The age for the Okanagan Highland locations is, in general,

text: Early Eocene

text: , with the sites that have current

text: uranium-lead

text: or

text: argon–argon

text: radiometric dates being of

text: Ypresian

text: age, while the undated sites or those given older dates being possibly slightly younger and

text: Lutetian

text: in age.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: Ypresian

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: NDQ_005716

answers: Ypresian age

answers: NDQ_005717

answers: Ypresian

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead or argon–argon

answers: NDQ_005712

answers: Ypresian

answers: NDQ_005713

answers: Ypresian

answers: NDQ_005714

answers: Ypresian

answers: NDQ_005715

answers: Ypresian

answers: NDQ_005716

answers: uranium-lead

answers: NDQ_005717

answers: Ypresian

answers: NDQ_005718

answers: Ypresian age,

answers: NDQ_005719

answers: argon–argon

answers: NDQ_005720

answers: Ypresian

text: Mount Sanford is mainly composed of andesite, and is an ancient peak, being mostly Pleistocene, although some of the upper parts of the mountain may be Holocene.  The mountain first began developing 900,000 years ago, when it began growing on top of three smaller shield volcanoes that had coalesced. Two notable events in the mountain's history include a large lava flow which traveled some  to the north east of the peak, and another flow which erupted from a rift zone on the flank of the volcano some 320,000 years ago. The second flow was basaltic in nature and marks the most recent activity of the volcano. The flow was dated using radiometric methods.

text: Mount Sanford is mainly composed of

text: andesite

text: , and is an ancient peak, being mostly

text: Pleistocene

text: , although some of the upper parts of the mountain may be

text: Holocene

text: .  The mountain first began developing 900,000 years ago, when it began growing on top of three smaller shield volcanoes that had coalesced. Two notable events in the mountain's history include a large lava flow which traveled some  to the north east of the peak, and another flow which erupted from a rift zone on the flank of the volcano some 320,000 years ago. The second flow was basaltic in nature and marks the most recent activity of the volcano. The flow was dated using

text: radiometric

text: methods.

answers: NDQ_005711

answers: radiometric methods

answers: NDQ_005712

answers: Pleistocene

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: How long does it take for carbon-14 to decay?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric methods

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiometric methods.

answers: NDQ_005712

answers: Pleistocene,

answers: NDQ_005713

answers: radiometric methods.

answers: NDQ_005714

answers: radiometric methods.

answers: NDQ_005715

answers: radiometric methods.

answers: NDQ_005716

answers: radiometric methods.

answers: NDQ_005717

answers: radiometric methods.

answers: NDQ_005718

answers: radiometric methods.

answers: NDQ_005719

answers: radiometric methods.

answers: NDQ_005720

answers: radiometric methods.

text: Unlike other isotopic dating methods, the "daughter" in fission track dating is an effect in the crystal rather than a daughter isotope.  Uranium-238 undergoes spontaneous fission decay at a known rate, and it is the only isotope with a decay rate that is relevant to the significant production of natural fission tracks; other isotopes have fission decay rates too slow to be of consequence. The fragments emitted by this fission process leave trails of damage (fossil tracks or ion tracks) in the crystal structure of the mineral that contains the uranium. The process of track production is essentially the same by which swift heavy ions produce ion tracks.Chemical etching of polished internal surfaces of these minerals reveals spontaneous fission tracks, and the track density can be determined.  Because etched tracks are relatively large (in the range 1 to 15 micrometres), counting can be done by optical microscopy, although other imaging techniques are used. The density of fossil tracks correlates with the cooling age of the sample and with uranium content, which needs to be determined independently.

text: Unlike other isotopic dating methods, the "

text: daughter

text: " in fission track dating is an effect in the

text: crystal

text: rather than a daughter isotope.

text: undergoes

text: spontaneous fission

text: decay at a known rate, and it is the only isotope with a decay rate that is relevant to the significant production of natural fission tracks; other isotopes have fission decay rates too slow to be of consequence. The fragments emitted by this fission process leave trails of damage (fossil tracks or

text: ion track

text: s) in the

text: crystal structure

text: of the mineral that contains the uranium. The process of track production is essentially the same by which

text: swift heavy ion

text: s produce ion tracks.Chemical etching of polished internal surfaces of these minerals reveals spontaneous fission tracks, and the track density can be determined.  Because etched tracks are relatively large (in the range 1 to 15 micrometres), counting can be done by

text: optical microscopy

text: , although other imaging techniques are used. The density of fossil tracks correlates with the cooling age of the sample and with uranium content, which needs to be determined independently.

answers: NDQ_005711

answers: isotopic dating

answers: NDQ_005712

answers: Uranium-238 undergoes spontaneous fission decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Uranium-238

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: uranium decay

answers: NDQ_005717

answers: etching of polished internal surfaces of these minerals

answers: NDQ_005718

answers: other isotopes have fission decay rates too slow to be of consequence

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: tracks.Chemical etching

answers: NDQ_005712

answers: cooling age

answers: NDQ_005713

answers: Uranium-238

answers: NDQ_005714

answers: Uranium-238

answers: NDQ_005715

answers: Uranium-238

answers: NDQ_005716

answers: cooling age

answers: NDQ_005717

answers: effect in the crystal rather than a daughter isotope.

answers: NDQ_005718

answers: needs to be determined independently.

answers: NDQ_005719

answers: Uranium-238

answers: NDQ_005720

answers: Uranium-238

text: The Aegean prehistorians felt so confident about their calculations that they rejected early radiocarbon dates in the 1970s for LMI/LCI Thera, as radiocarbon suggested a date about a century earlier than the traditional dates.

text: The Aegean prehistorians felt so confident about their calculations that they rejected early

text: radiocarbon dates

text: in the 1970s for LMI/LCI Thera, as radiocarbon suggested a date about a century earlier than the traditional dates.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: a century earlier than the traditional dates

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon suggested a date about a century earlier than the traditional dates.

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon suggested a date about a century earlier than the traditional dates.

answers: NDQ_005718

answers: radiocarbon suggested a date about a century earlier

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: Through radiocarbon dating, logs in the church have been dated to 1190, which somewhat contradicts previous datings of the church. There are some claims that the church was built after 1326, but this seems to be outside the error envelope of radiocarbon dating. It could be that the church was rebuilt from materials used in an earlier church. There is, however, a written account of the church's existence in 1327.

text: Through

text: radiocarbon dating

text: , logs in the church have been dated to 1190, which somewhat contradicts previous datings of the church. There are some claims that the church was built after 1326, but this seems to be outside the error envelope of radiocarbon dating. It could be that the church was rebuilt from materials used in an earlier church. There is, however, a written account of the church's existence in 1327.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon is a noble gas

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: error envelope

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon dating,

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 1327.

answers: NDQ_005716

answers: radiocarbon dating,

answers: NDQ_005717

answers: 1190,

answers: NDQ_005718

answers: error envelope

answers: NDQ_005719

answers: radiocarbon dating,

answers: NDQ_005720

answers: radiocarbon dating,

text: Uranium-lead dating is usually performed on the mineral zircon (ZrSiO), though other materials can be used.  Zircon incorporates uranium atoms into its crystalline structure as substitutes for zirconium, but strongly rejects lead. It has a high blocking temperature, is resistant to mechanical weathering and is chemically inert.  Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. These can be dated by a SHRIMP ion microprobe.

text: Uranium

text: lead

text: dating is usually performed on the mineral

text: zircon

text: (ZrSiO), though other materials can be used.  Zircon incorporates uranium

text: atom

text: s into its crystalline structure as substitutes for

text: zirconium

text: , but strongly rejects lead. It has a high blocking temperature, is resistant to mechanical weathering and is chemically inert.  Zircon also forms multiple crystal layers during metamorphic events, which each may record an isotopic age of the event. These can be dated by a SHRIMP

text: ion

text: microprobe.

answers: NDQ_005711

answers: Uranium

answers: NDQ_005712

answers: zircon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Uranium-lead dating

answers: NDQ_005715

answers: NDQ_005716

answers: Zircon

answers: NDQ_005717

answers: zircon

answers: NDQ_005718

answers: Zircon incorporates uranium atoms into its crystalline structure

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: a SHRIMP ion microprobe.

answers: NDQ_005712

answers: isotopic age

answers: NDQ_005713

answers: zircon

answers: NDQ_005714

answers: Uranium-lead

answers: NDQ_005715

answers: zircon

answers: NDQ_005716

answers: Uranium-lead dating

answers: NDQ_005717

answers: zircon

answers: NDQ_005718

answers: high blocking temperature,

answers: NDQ_005719

answers: zircon

answers: NDQ_005720

answers: (ZrSiO),

text: The method was developed by Willard Libby in the late 1940s and soon became a standard tool for archaeologists. Libby received the Nobel Prize for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting radiocarbon combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire  by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of  it contains begins to decrease as the  undergoes radioactive decay. Measuring the amount of  in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less  there is to be detected, and because the half-life of  (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by radiocarbon dating are around 50,000 years ago, although special preparation methods occasionally permit dating of older samples.

text: The method was developed by

text: Willard Libby

text: in the late 1940s and soon became a standard tool for archaeologists. Libby received the

text: Nobel Prize

text: for his work in 1960. The radiocarbon dating method is based on the fact that radiocarbon is constantly being created in the atmosphere by the interaction of

text: cosmic ray

text: s with atmospheric

text: nitrogen

text: . The resulting radiocarbon combines with atmospheric

text: oxygen

text: to form radioactive

text: carbon dioxide

text: , which is incorporated into plants by

text: photosynthesis

text: ; animals then acquire  by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and from that point onwards the amount of  it contains begins to decrease as the  undergoes

text: radioactive decay

text: . Measuring the amount of  in a sample from a dead plant or animal such as a piece of wood or a fragment of bone provides information that can be used to calculate when the animal or plant died. The older a sample is, the less  there is to be detected, and because the

text: half-life

text: of  (the period of time after which half of a given sample will have decayed) is about 5,730 years, the oldest dates that can be reliably measured by radiocarbon dating are around 50,000 years ago, although special preparation methods occasionally permit dating of older samples.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon is constantly being created in the atmosphere

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: the older a sample is, the less there is to be detected

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: it stops exchanging carbon with its environment

answers: NDQ_005717

answers: the older a sample is, the less there is to be detected

answers: NDQ_005718

answers: The older a sample is, the less there is to be detected

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Measuring the amount of in a sample

answers: NDQ_005712

answers: 50,000 years ago,

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 50,000 years ago,

answers: NDQ_005716

answers: it stops exchanging carbon with its environment,

answers: NDQ_005717

answers: special preparation methods occasionally permit dating of older samples.

answers: NDQ_005718

answers: The older a sample is, the less there is to be detected,

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: 5,730 years,

text: Two ignimbrite eruptions have taken place in Panizos. A number of lava flows also formed. Volcanic activity took place in the Late Miocene. The main Cerro Panizos ignimbrite lies on top three older ignimbrite layers. Potassium-argon dating has yielded ages of 9.7 ± 0.4, 8.49 ± 0.2 and 9.4 mya. Dates often differ between newly established and old established dates, presumably due to xenolith contamination.

text: Two ignimbrite eruptions have taken place in Panizos. A number of lava flows also formed. Volcanic activity took place in the Late Miocene. The main Cerro Panizos ignimbrite lies on top three older ignimbrite layers.

text: Potassium-argon dating

text: has yielded ages of 9.7 ± 0.4, 8.49 ± 0.2 and 9.4

text: mya

text: . Dates often differ between newly established and old established dates, presumably due to xenolith contamination.

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: xenolith contamination

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-argon dating has yielded ages

answers: NDQ_005715

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: 9.7  0.4

answers: NDQ_005718

answers: xenolith contamination

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: xenolith contamination.

answers: NDQ_005713

answers: Potassium-argon dating

answers: NDQ_005714

answers: xenolith contamination.

answers: NDQ_005715

answers: 9.7 <unk> 0.4,

answers: NDQ_005716

answers: ages

answers: NDQ_005717

answers: 9.4 mya.

answers: NDQ_005718

answers: Dates often differ between newly established and old established dates,

answers: NDQ_005719

answers: 9.4 mya.

answers: NDQ_005720

answers: Potassium-argon dating

text: One of the most widely used and well-known absolute dating techniques is carbon-14 (or radiocarbon) dating, which is used to date organic remains.  This is a radiometric technique since it is based on radioactive decay.  Cosmic radiation entering the earth’s atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide.  Carbon-14 moves up the food chain as animals eat plants and as predators eat other animals.  With death, the uptake of carbon-14 stops.

text: One of the most widely used and well-known absolute dating techniques is carbon-14 (or

text: radiocarbon

text: ) dating, which is used to date organic remains.  This is a radiometric technique since it is based on radioactive decay.  Cosmic radiation entering the earth’s atmosphere produces carbon-14, and plants take in carbon-14 as they fix carbon dioxide.  Carbon-14 moves up the food chain as animals eat plants and as predators eat other animals.  With death, the uptake of carbon-14 stops.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: carbon-14

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radioactive decay

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 stop

answers: NDQ_005717

answers: is used to date organic remains

answers: NDQ_005718

answers: it is based on radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radioactive decay.

answers: NDQ_005712

answers: radioactive decay.

answers: NDQ_005713

answers: radioactive decay.

answers: NDQ_005714

answers: it is based on radioactive decay.

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: the uptake of carbon-14 stops.

answers: NDQ_005717

answers: Cosmic radiation entering the earth’s atmosphere produces carbon-14,

answers: NDQ_005718

answers: radioactive decay.

answers: NDQ_005719

answers: carbon-14

answers: NDQ_005720

answers: carbon-14

text: Princely Jets Pvt Limited: (April 2005 till date)

text: Princely Jets Pvt Limited: (April 2005 till date)

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Princely Jets Pvt

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: isotope dating

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: (April 2005 till date)

answers: NDQ_005720

answers: NDQ_005711

answers: (April 2005

answers: NDQ_005712

answers: Princely Jets Pvt Limited:

answers: NDQ_005713

answers: Princely Jets Pvt Limited:

answers: NDQ_005714

answers: Princely Jets Pvt Limited:

answers: NDQ_005715

answers: Princely Jets Pvt Limited:

answers: NDQ_005716

answers: Princely Jets Pvt Limited: (April 2005 till date)

answers: NDQ_005717

answers: (April 2005 till date)

answers: NDQ_005718

answers: context:

answers: NDQ_005719

answers: Princely Jets

answers: NDQ_005720

answers: Princely Jets Pvt Limited:

text: On October 1, 2009, paleontologists formally announced the discovery of the relatively complete A. ramidus fossil skeleton first unearthed in 1994. The fossil is the remains of a small-brained 50-kilogram (110 lb) female, nicknamed "Ardi", and includes most of the skull and teeth, as well as the pelvis, hands, and feet. It was discovered in Ethiopia's harsh Afar desert at a site called Aramis in the Middle Awash region. Radiometric dating of the layers of volcanic ash encasing the deposits suggest that Ardi lived about 4.4 million years ago. This date, however, has been questioned by others. Fleagle and Kappelman suggest that the region in which Ardi was found is difficult to date radiometrically, and they argue that Ardi should be dated at 3.9 million years.

text: On October 1,

text: , paleontologists formally announced the discovery of the relatively complete A. ramidus fossil skeleton first unearthed in 1994. The fossil is the remains of a small-brained 50-kilogram (110 lb) female, nicknamed "Ardi", and includes most of the skull and teeth, as well as the pelvis, hands, and feet. It was discovered in Ethiopia's harsh

text: Afar desert

text: at a site called

text: Aramis

text: in the Middle Awash region. Radiometric dating of the layers of volcanic ash encasing the deposits suggest that Ardi lived about 4.4 million years ago. This date, however, has been questioned by others. Fleagle and Kappelman suggest that the region in which Ardi was found is difficult to date radiometrically, and they argue that Ardi should be dated at 3.9 million years.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: volcanic ash

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Ardi lived about 4.4 million years ago

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Radiometric dating

answers: NDQ_005718

answers: difficult to date radiometrically

answers: NDQ_005719

answers: radiometric

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: layers of volcanic ash

answers: NDQ_005712

answers: 4.4 million years ago.

answers: NDQ_005713

answers: 4.4 million years ago.

answers: NDQ_005714

answers: Radiometric dating of the layers of volcanic ash

answers: NDQ_005715

answers: 3.9

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: 4.4 million years ago.

answers: NDQ_005718

answers: the region in which Ardi was found is difficult to date radiometrically,

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: The potassium-argon method was utilized to determine the age of volcanism at Pilot Knob. This method is based upon the decay of the radioactive isotope of potassium (potassium 40) to argon 40, an isotope of argon, an inert gas. By knowing the concentration of potassium in a rock mineral and the amount of argon gas produced by radioactive decay trapped within the minerals, an age can be assigned to the rock because the decay rate of potassium 40 to argon 40 is known from experimental work. The age of Pilot Knob volcanism dated through the potassium-argon method is 79.5 +/- 3 million years, and agrees with the age derived by correlation with fossils to other radiometrically dated deposits.

text: The

text: potassium-argon

text: method was utilized to determine the age of volcanism at Pilot Knob. This method is based upon the decay of the radioactive

text: isotope

text: of

text: potassium

text: (potassium 40) to argon 40, an isotope of

text: argon

text: , an inert gas. By knowing the concentration of potassium in a rock mineral and the amount of argon gas produced by radioactive decay trapped within the minerals, an age can be assigned to the rock because the decay rate of potassium 40 to argon 40 is known from experimental work. The age of Pilot Knob volcanism dated through the potassium-argon method is 79.5 +/- 3 million years, and agrees with the age derived by correlation with fossils to other radiometrically dated deposits.

answers: NDQ_005711

answers: The potassium-argon method

answers: NDQ_005712

answers: decay rate of potassium 40 to argon 40 is known from experimental work

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: the decay rate of potassium 40 to argon 40

answers: NDQ_005715

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: decay of the radioactive isotope of potassium

answers: NDQ_005718

answers: the age derived by correlation with fossils

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: correlation with fossils

answers: NDQ_005712

answers: decay rate of potassium 40 to argon 40 is known from experimental work.

answers: NDQ_005713

answers: The potassium-argon method

answers: NDQ_005714

answers: radiometrically dated deposits.

answers: NDQ_005715

answers: 79.5 +/- 3 million years,

answers: NDQ_005716

answers: fossils

answers: NDQ_005717

answers: decay of the radioactive isotope of potassium

answers: NDQ_005718

answers: correlation with fossils

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: The potassium-argon

text: In November 2010, the final dating of sand grains via infrared-radio fluorescence (IR-RF) and the dating of the teeth via a combined electron-spin - and uranium-lead dating was published in the Proceedings of the National Academy of Sciences wherein the age of the fossil was concluded as to be of 609,000 ± 40,000 years.

text: In November 2010, the final dating of sand grains via

text: infrared

text: -radio fluorescence (IR-RF) and the dating of the teeth via a combined

text: electron-spin

text: - and

text: uranium-lead

text: dating was published in the

entity_name: Proceedings of the National Academy of Sciences of the United States of America

text: Proceedings of the National Academy of Sciences

text: wherein the age of the fossil was concluded as to be of 609,000 ± 40,000 years.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: infrared-radio

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: IR-RF

answers: NDQ_005718

answers: age of the fossil

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: infrared-radio fluorescence

answers: NDQ_005712

answers: 609,000 <unk> 40,000 years.

answers: NDQ_005713

answers: infrared-radio fluorescence

answers: NDQ_005714

answers: uranium-lead dating

answers: NDQ_005715

answers: 609,000 <unk> 40,000 years.

answers: NDQ_005716

answers: infrared-radio fluorescence

answers: NDQ_005717

answers: infrared-radio fluorescence

answers: NDQ_005718

answers: 609,000 <unk> 40,000 years.

answers: NDQ_005719

answers: infrared-radio fluorescence

answers: NDQ_005720

answers: 609,000 <unk> 40,000 years.

text: The coins and votive tablets found at the site of the temple roughly date the upper limit of Roman control of the pass. The youngest date to the reign of Theodosius II (1st half of the 5th century). These and other artifacts are stored in the monastery museum. Fragments of the marble temple, some with inscriptions, have been incorporated into many structures of the village of Bourg-Saint-Pierre on the Swiss side of the pass. The Roman milestone for mile XXIII was also brought to the center of the settlement from the top of the pass.

text: The coins and votive tablets found at the site of the temple roughly date the upper limit of Roman control of the pass. The youngest date to the reign of

text: Theodosius II

text: (1st half of the 5th century). These and other artifacts are stored in the monastery museum. Fragments of the marble temple, some with inscriptions, have been incorporated into many structures of the village of

text: Bourg-Saint-Pierre

text: on the Swiss side of the pass. The Roman

text: milestone

text: for mile XXIII was also brought to the center of the settlement from the top of the pass.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: coins and votive tablets found at the site of the temple roughly date the upper limit of Roman control of the pass

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The youngest date to the reign of Theodosius II (1st half of the 5th century

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: The youngest date to the reign of Theodosius II

answers: NDQ_005712

answers: upper limit of Roman control of the pass.

answers: NDQ_005713

answers: The youngest date to the reign of Theodosius II

answers: NDQ_005714

answers: upper limit of Roman control of the pass.

answers: NDQ_005715

answers: incorporated into many structures of the village of Bourg-Saint-Pierre

answers: NDQ_005716

answers: date the upper limit of Roman control of the pass.

answers: NDQ_005717

answers: The youngest date to the reign of Theodosius II

answers: NDQ_005718

answers: upper limit of Roman control of the pass.

answers: NDQ_005719

answers: The youngest date to the reign of Theodosius II

answers: NDQ_005720

answers: The youngest date to the reign of Theodosius II

text: Settlements of culturally similar early populations of ancient Sri Lanka and ancient Tamil Nadu in India were excavated at megalithic burial sites at Pomparippu on the west coast and in Kathiraveli on the east coast of the island. Bearing a remarkable resemblance to burials in the Early Pandyan Kingdom, these sites were established between the 5th century BCE and 2nd century CE. Excavated ceramic sequences similar to that of Arikamedu were found in Kandarodai (Kadiramalai) on the north coast, dated to 1300 BCE. Cultural similarities in burial practices in South India and Sri Lanka were dated by archaeologists to 10th century BCE. However, Indian history and archaeology have pushed the date back to 15th century BCE. In Sri Lanka, there is radiometric evidence from Anuradhapura that the non-Brahmi symbol-bearing black and red ware occur in the 10th century BCE. The skeletal remains of an Early Iron Age chief were excavated in Anaikoddai, Jaffna District. The name Ko Veta is engraved in Brahmi script on a seal buried with the skeleton and is assigned by the excavators to the 3rd century BCE. Ko, meaning "King" in Tamil, is comparable to such names as Ko Atan, Ko Putivira and Ko Ra-pumaan occurring in contemporary Tamil Brahmi inscriptions of ancient South India and Egypt.

text: Settlements of culturally similar early populations of ancient Sri Lanka and ancient

text: Tamil Nadu

text: in India were excavated at

text: megalithic burial sites

text: at Pomparippu on the west coast and in

text: Kathiraveli

text: on the east coast of the island. Bearing a remarkable resemblance to burials in the

text: Early Pandyan Kingdom

text: , these sites were established between the 5th century BCE and 2nd century CE. Excavated

text: ceramic

text: sequences similar to that of

text: Arikamedu

text: were found in

text: Kandarodai

text: (Kadiramalai) on the north coast, dated to 1300 BCE. Cultural similarities in burial practices in South India and Sri Lanka were dated by archaeologists to 10th century BCE. However, Indian history and archaeology have pushed the date back to 15th century BCE. In Sri Lanka, there is radiometric evidence from

text: Anuradhapura

text: that the non-

text: Brahmi

text: symbol-bearing

text: black and red ware

text: occur in the 10th century BCE. The skeletal remains of an

text: Early Iron Age

text: chief were excavated in Anaikoddai,

text: Jaffna District

text: . The name Ko Veta is engraved in Brahmi script on a seal buried with the skeleton and is assigned by the excavators to the 3rd century BCE. Ko, meaning "King" in Tamil, is comparable to such names as Ko Atan, Ko Putivira and Ko Ra-pumaan occurring in contemporary

text: Tamil Brahmi

text: inscriptions of ancient South India and

text: Egypt

answers: NDQ_005711

answers: radiometric evidence

answers: NDQ_005712

answers: BCE

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric evidence from Anuradhapura

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric evidence

answers: NDQ_005717

answers: radiometric evidence from Anuradhapura that the non-Brahmi symbol-bearing black and red ware occur in the 10th century BCE

answers: NDQ_005718

answers: Indian history and archaeology have pushed the date back to 15th century BCE

answers: NDQ_005719

answers: radiometric evidence

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: archaeologists

answers: NDQ_005712

answers: 10th century BCE.

answers: NDQ_005713

answers: 10th century BCE.

answers: NDQ_005714

answers: radiometric evidence

answers: NDQ_005715

answers: 10th century BCE.

answers: NDQ_005716

answers: radiometric

answers: NDQ_005717

answers: 10th century BCE.

answers: NDQ_005718

answers: pushed the date back to 15th century BCE.

answers: NDQ_005719

answers: 1300 BCE.

answers: NDQ_005720

answers: 1300 BCE.

text: Together with stratigraphic principles, radiometric dating methods are used in geochronology to establish the geological time scale. Among the best-known techniques are radiocarbon dating, potassium-argon dating and uranium-lead dating. By allowing the establishment of geological timescales, it provides a significant source of information about the ages of fossils and the deduced rates of evolutionary change. Radiometric dating is also used to date archaeological materials, including ancient artifacts.

text: Together with

text: stratigraphic principles

text: , radiometric dating methods are used in

text: geochronology

text: to establish the

text: geological time scale

text: . Among the best-known techniques are

text: radiocarbon dating

text: potassium-argon dating

text: and

text: uranium-lead dating

text: . By allowing the establishment of geological timescales, it provides a significant source of information about the ages of

text: fossil

text: s and the deduced rates of

text: evolution

text: ary change. Radiometric dating is also used to date

text: archaeological

text: materials, including ancient artifacts.

answers: NDQ_005711

answers: radiocarbon dating

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: uranium-lead

answers: NDQ_005718

answers: uranium-lead dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: archaeological materials, including ancient artifacts.

answers: NDQ_005712

answers: ancient artifacts.

answers: NDQ_005713

answers: Radiometric dating is also used to date archaeological materials,

answers: NDQ_005714

answers: Radiometric dating is also used to date archaeological materials,

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: ages of fossils

answers: NDQ_005717

answers: deduced rates of evolutionary change.

answers: NDQ_005718

answers: ages of fossils and the deduced rates of evolutionary change.

answers: NDQ_005719

answers: potassium-argon dating and uranium-lead dating.

answers: NDQ_005720

answers: uranium-lead dating.

text: All the extinct genera listed to the right are ancestral to, or offshoots of, Homo. Few fossil specimens on the Pan side of the split have been found—the first discovery of a fossil chimpanzee was published in 2005; it was from Kenya's East African Rift Valley and dated to between 545 thousand years, radiometric, (kyr) and 284 kyr (via argon–argon dating). However, both Orrorin and Sahelanthropus existed around the time of the split, and so may be ancestral to both Pan and Homo.

text: All the extinct genera listed to the right are ancestral to, or offshoots of, Homo. Few fossil specimens on the Pan side of the split have been found—the first discovery of a fossil chimpanzee was published in 2005; it was from

text: Kenya

text: 's

text: East African Rift

text: Valley and dated to between 545 thousand years, radiometric, (kyr) and 284 kyr (via

text: argon–argon dating

text: ). However, both

text: Orrorin

text: and

text: Sahelanthropus

text: existed around the time of the split, and so may be ancestral to both Pan and Homo.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: argon–argon

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric

answers: NDQ_005717

answers: 284 kyr

answers: NDQ_005718

answers: argon–argon dating

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: (kyr)

answers: NDQ_005712

answers: argon–argon dating).

answers: NDQ_005713

answers: radiometric,

answers: NDQ_005714

answers: argon–argon

answers: NDQ_005715

answers: 545 thousand years,

answers: NDQ_005716

answers: argon–argon

answers: NDQ_005717

answers: argon–argon

answers: NDQ_005718

answers: Few fossil specimens on the Pan side of the split have been found—the

answers: NDQ_005719

answers: argon–argon dating).

answers: NDQ_005720

answers: argon–argon dating).

text: The  BFI has limited footage of the fair dating from 1975

text: The

text: BFI

text: has limited footage of the fair dating from 1975

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive elements are present

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 1975 is the earliest year

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 1975

answers: NDQ_005712

answers: 1975

answers: NDQ_005713

answers: 1975

answers: NDQ_005714

answers: 1975

answers: NDQ_005715

answers: 1975

answers: NDQ_005716

answers: 1975

answers: NDQ_005717

answers: 1975

answers: NDQ_005718

answers: footage of the fair dating from 1975

answers: NDQ_005719

answers: 1975

answers: NDQ_005720

answers: 1975

text: Inside the church is a three-bay north arcade of pointed arches carried on octagonal columns.  A small passage leads into the base of the tower; this is protected by an iron gate (or yett).  The chancel arch dates from the 19th century, and contains a recess for an aumbry.  In the east wall of the chancel to the left of the altar is a carved Roman corbel stone.  To the right of the altar a door leads into the vestry.  The stained glass in the north aisle windows dates from 1898 and is by Heaton, Butler and Bayne; one of these depicts Edward I.  The rest of the stained glass dates from 1897, and is by Seward and Company.

text: Inside the church is a three-bay north arcade of pointed arches carried on octagonal columns.  A small passage leads into the base of the tower; this is protected by an iron gate (or

text: yett

text: ).  The chancel arch dates from the 19th century, and contains a recess for an

text: aumbry

text: .  In the east wall of the chancel to the left of the altar is a carved Roman

text: corbel

text: stone.  To the right of the altar a door leads into the vestry.  The stained glass in the north aisle windows dates from 1898 and is by

text: Heaton, Butler and Bayne

text: ; one of these depicts Edward I.  The rest of the stained glass dates from 1897, and is by Seward and Company.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Roman corbel stone

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The stain glass in the north aisle windows

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: NDQ_005711

answers: 1898

answers: NDQ_005712

answers: 19th century,

answers: NDQ_005713

answers: 1898

answers: NDQ_005714

answers: 1898

answers: NDQ_005715

answers: 1898

answers: NDQ_005716

answers: 1898

answers: NDQ_005717

answers: 1898

answers: NDQ_005718

answers: a recess for an aumbry.

answers: NDQ_005719

answers: 1898

answers: NDQ_005720

answers: 1898

text: Radiocarbon dating suggests that Dynasty XVIII may have started a few years earlier than the conventional date of 1550 BC. The radiocarbon date range for its beginning is 1570–1544 BC, the mean point of which is 1557 BC.

text: Radiocarbon dating

text: suggests that Dynasty XVIII may have started a few years earlier than the conventional date of 1550 BC. The radiocarbon date range for its beginning is 1570–1544 BC, the mean point of which is 1557 BC.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 1570–1544 BC

answers: NDQ_005718

answers: The radiocarbon date range is 1570–1544 BC

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon

answers: NDQ_005715

answers: 1557 BC.

answers: NDQ_005716

answers: Radiocarbon dating

answers: NDQ_005717

answers: 1570–1544 BC,

answers: NDQ_005718

answers: The radiocarbon date range for its beginning is 1570–1544 BC,

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: Yet some radiometric datings using the argon-method find much earlier Tournaisian ages for the intrusion of the Estivaux granite and for the motions along mylonite zones within the Saut-du-Saumon orthogneiss. These findings imply a tectonic phase in the southern Limousin already during Mississippian times (Bretonic Phase).

text: Yet some

text: radiometric datings

text: using the

text: argon

text: -method find much earlier Tournaisian ages for the intrusion of the Estivaux granite and for the motions along mylonite zones within the Saut-du-Saumon orthogneiss. These findings imply a tectonic phase in the southern Limousin already during Mississippian times (

text: Bretonic Phase

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: Tournaisian

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: argon-method

answers: NDQ_005718

answers: argon-method

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: argon-method

answers: NDQ_005712

answers: argon-method

answers: NDQ_005713

answers: argon-method

answers: NDQ_005714

answers: radiometric datings using the argon-method

answers: NDQ_005715

answers: argon-method

answers: NDQ_005716

answers: argon-method

answers: NDQ_005717

answers: argon-method find much earlier Tournaisian ages

answers: NDQ_005718

answers: argon-method find much earlier Tournaisian ages

answers: NDQ_005719

answers: radiometric datings using the argon-method

answers: NDQ_005720

answers: argon-method

text: The radiometric age of Lake Tauca ranges from 72,600 to 7200 BP. The duration of the lake highstands may be overestimated due to radiation scatter. Radiocarbon dates have been obtained on crusts containing calcite, gastropod shells, stromatolites and structures left behind by algae. The Lake Tauca shorelines formed over more than century-long periods.

text: The

text: radiometric age

text: of Lake Tauca ranges from 72,600 to 7200 BP. The duration of the lake highstands may be overestimated due to radiation scatter.

text: Radiocarbon

text: dates have been obtained on crusts containing

text: calcite

text: , gastropod shells,

text: stromatolite

text: s and structures left behind by algae. The Lake Tauca shorelines formed over more than century-long periods.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Radiocarbon

answers: NDQ_005718

answers: may be overestimated due to radiation scatter

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon

answers: NDQ_005715

answers: 72,600 to 7200 BP.

answers: NDQ_005716

answers: Radiocarbon dates

answers: NDQ_005717

answers: Radiocarbon dates have been obtained on crusts

answers: NDQ_005718

answers: radiation scatter.

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: Radiocarbon dates

text: In petrology, metamorphic phases can be distinguished by analysis of minerals and microstructures (petrography) in metamorphic rocks. By analysing the sequence in which the minerals and structures were formed, more than one phase can be found in most metamorphic rocks (this is called polymetamorphism). By radiometric dating the absolute age of the different phases of mineral growth can be determined, showing when the rock was under certain pressure-temperature conditions. The obtained age is not necessarily the age of a tectonic phase, but can show when the tectonic phase ended and crystallisation of new minerals occurred.

text: In petrology, metamorphic phases can be distinguished by analysis of

text: mineral

text: s and

text: microstructure

text: s (

text: petrography

text: ) in

text: metamorphic rock

text: s. By analysing the sequence in which the minerals and structures were formed, more than one phase can be found in most metamorphic rocks (this is called

text: polymetamorphism

text: ). By

text: radiometric dating

text: the

text: absolute age

text: of the different phases of mineral growth can be determined, showing when the rock was under certain

text: pressure

text: temperature

text: conditions. The obtained age is not necessarily the age of a tectonic phase, but can show when the tectonic phase ended and

text: crystallisation

text: of new minerals occurred.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: pressure-temperature conditions

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: the absolute age of the different phases of mineral growth can be determined

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: absolute age of the different phases of mineral growth can be determined

answers: NDQ_005718

answers: The obtained age is not necessarily the age of a tectonic phase

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: pressure-temperature conditions.

answers: NDQ_005712

answers: pressure-temperature conditions.

answers: NDQ_005713

answers: radiometric dating the absolute age of the different phases of mineral growth

answers: NDQ_005714

answers: showing when the rock was under certain pressure-temperature conditions.

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating the absolute age of the different phases of mineral growth

answers: NDQ_005718

answers: not necessarily the age of a tectonic phase,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: While the moment in time at which a particular nucleus decays is unpredictable, a collection of atoms of a radioactive nuclide decays exponentially at a rate described by a parameter known as the half-life, usually given in units of years when discussing dating techniques. After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a "daughter" nuclide or decay product. In many cases, the daughter nuclide itself is radioactive, resulting in a decay chain, eventually ending with the formation of a stable (nonradioactive) daughter nuclide; each step in such a chain is characterized by a distinct half-life. In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter. Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years (e.g., tritium) to over 100 billion years (e.g., Samarium-147).

text: While the moment in time at which a particular nucleus decays is unpredictable, a collection of atoms of a radioactive nuclide decays

text: exponentially

text: at a rate described by a parameter known as the

text: half-life

text: , usually given in units of years when discussing dating techniques. After one half-life has elapsed, one half of the atoms of the nuclide in question will have decayed into a "daughter" nuclide or

text: decay product

text: . In many cases, the daughter nuclide itself is radioactive, resulting in a

text: decay chain

text: , eventually ending with the formation of a stable (nonradioactive) daughter nuclide; each step in such a chain is characterized by a distinct half-life. In these cases, usually the half-life of interest in radiometric dating is the longest one in the chain, which is the rate-limiting factor in the ultimate transformation of the radioactive nuclide into its stable daughter. Isotopic systems that have been exploited for radiometric dating have half-lives ranging from only about 10 years (e.g.,

text: tritium

text: ) to over 100 billion years (e.g.,

answers: NDQ_005711

answers: half-life

answers: NDQ_005712

answers: half-life of interest in radiometric dating is the longest one in the chain

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: half-life

answers: NDQ_005715

answers: 5,730

answers: NDQ_005716

answers: half-life

answers: NDQ_005717

answers: half-life

answers: NDQ_005718

answers: the moment in time at which a particular nucleus decays is unpredictable

answers: NDQ_005719

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: half-life,

answers: NDQ_005712

answers: Isotopic systems

answers: NDQ_005713

answers: half-life,

answers: NDQ_005714

answers: radiometric dating is the longest one in the chain,

answers: NDQ_005715

answers: 10 years

answers: NDQ_005716

answers: half-life,

answers: NDQ_005717

answers: usually the half-life

answers: NDQ_005718

answers: rate-limiting factor

answers: NDQ_005719

answers: radiometric dating have half-lives ranging from only about 10 years

answers: NDQ_005720

answers: 100 billion years (e.g., Samarium-147).

text: Uranium-thorium dating, also called thorium-230 dating, uranium-series disequilibrium dating or uranium-series dating, is a radiometric dating technique commonly used to determine the age of calcium carbonate materials such as speleothem or coral.  Unlike other commonly used radiometric dating techniques such as rubidium-strontium or uranium-lead dating, the uranium-thorium technique does not measure accumulation of a stable end-member decay product.  Instead, the uranium-thorium technique calculates an age from the degree to which secular equilibrium has been restored between the radioactive isotope thorium-230 and its radioactive parent uranium-234 within a sample.

text: Uranium-thorium dating, also called thorium-230 dating, uranium-series disequilibrium dating or uranium-series dating, is a

text: radiometric dating

text: technique commonly used to determine the age of

text: calcium carbonate

text: materials such as

text: speleothem

text: or

text: coral

text: .  Unlike other commonly used

text: radiometric dating

text: techniques such as

text: rubidium-strontium

text: or

text: uranium-lead

text: dating, the uranium-thorium technique does not measure accumulation of a stable end-member

text: decay product

text: .  Instead, the uranium-thorium technique calculates an age from the degree to which

text: secular equilibrium

text: has been restored between the

text: radioactive

text: isotope

text: thorium

text: -230 and its radioactive parent

text: uranium

text: -234 within a sample.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: calcium carbonate

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-thorium dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: thorium-230 dating

answers: NDQ_005718

answers: does not measure accumulation of a stable end-member decay product

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: the degree to which secular equilibrium has been restored

answers: NDQ_005712

answers: the degree to which secular equilibrium has been restored

answers: NDQ_005713

answers: does not measure accumulation of a stable end-member decay product.

answers: NDQ_005714

answers: does not measure accumulation of a stable end-member decay product.

answers: NDQ_005715

answers: uranium-234

answers: NDQ_005716

answers: accumulation of a stable end-member decay product.

answers: NDQ_005717

answers: uranium-234

answers: NDQ_005718

answers: does not measure accumulation of a stable end-member decay product.

answers: NDQ_005719

answers: rubidium-strontium

answers: NDQ_005720

answers: uranium-lead dating,

text: The spontaneous fission of uranium-238 and uranium-235 does leave trails of damage in the crystal structure of uranium-containing minerals when the fission fragments recoil through them. These trails, or fission tracks, are the foundation of the radiometric dating method called fission track dating.

text: The spontaneous fission of uranium-238 and uranium-235 does leave trails of damage in the

text: crystal structure

text: of uranium-containing minerals when the fission fragments recoil through them. These trails, or fission tracks, are the foundation of the

text: radiometric dating

text: method called

text: fission track dating

answers: NDQ_005711

answers: fission tracks

answers: NDQ_005712

answers: fission tracks

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: fission tracks

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: fission tracks

answers: NDQ_005718

answers: leave trails of damage in the crystal structure

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: fission track dating.

answers: NDQ_005712

answers: uranium-238 and uranium-235

answers: NDQ_005713

answers: fission track dating.

answers: NDQ_005714

answers: radiometric dating method called fission track dating.

answers: NDQ_005715

answers: fission track dating.

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: fission track dating.

answers: NDQ_005718

answers: leave trails of damage

answers: NDQ_005719

answers: fission track dating.

answers: NDQ_005720

answers: fission track dating.

text: In statistics, a truncated distribution is a conditional distribution that results from restricting the domain of some other probability distribution. Truncated distributions arise in practical statistics in cases where the ability to record, or even to know about, occurrences is limited to values which lie above or below a given threshold or within a specified range. For example, if the dates of birth of children in a school are examined, these would typically be subject to truncation relative to those of all children in the area given that the school accepts only children in a given age range on a specific date. There would be no information about how many children in the locality had dates of birth before or after the school's cutoff dates if only a direct approach to the school were used to obtain information.

text: In

text: statistics

text: , a truncated distribution is a

text: conditional distribution

text: that results from restricting the domain of some other

text: probability distribution

text: . Truncated distributions arise in practical statistics in cases where the ability to record, or even to know about, occurrences is limited to values which lie above or below a given threshold or within a specified range. For example, if the dates of birth of children in a school are examined, these would typically be subject to truncation relative to those of all children in the area given that the school accepts only children in a given age range on a specific date. There would be no information about how many children in the locality had dates of birth before or after the school's cutoff dates if only a direct approach to the school were used to obtain information.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: truncated distribution

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: the ability to record, or even to know about, occurrences is limited to values which lie above or below a given threshold or within a specified range

answers: NDQ_005718

answers: no information about how many children in the locality had dates of birth before or after the school's cutoff dates

answers: NDQ_005719

answers: truncated distributions

answers: NDQ_005720

answers: NDQ_005711

answers: dates of birth

answers: NDQ_005712

answers: given age range

answers: NDQ_005713

answers: Truncated distributions

answers: NDQ_005714

answers: Truncated distributions arise in practical statistics

answers: NDQ_005715

answers: In statistics, a truncated distribution

answers: NDQ_005716

answers: a specific date.

answers: NDQ_005717

answers: these would typically be subject to truncation

answers: NDQ_005718

answers: the school accepts only children in a given age range

answers: NDQ_005719

answers: dates of birth of children

answers: NDQ_005720

answers: In statistics, a truncated distribution

text: Radiocarbon dating methods produce data that must then be further manipulated in order to calculate a resulting "radiocarbon age".

text: Radiocarbon dating methods produce data that must then be further manipulated in order to calculate a resulting "radiocarbon age".

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon age

answers: NDQ_005717

answers: radiocarbon is used to determine the age of a substance

answers: NDQ_005718

answers: data can be manipulated

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: "radiocarbon age".

answers: NDQ_005714

answers: "radiocarbon age".

answers: NDQ_005715

answers: "radiocarbon age".

answers: NDQ_005716

answers: "radiocarbon age".

answers: NDQ_005717

answers: "radiocarbon age".

answers: NDQ_005718

answers: produce data that must then be further manipulated

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: "radiocarbon age".

text: In 2014, Arthur O. Tucker and Rexford H. Talbert published a paper claiming a positive identification of 37 plants, 6 animals, and 1 mineral referenced in the manuscript to plant drawings in the Libellus de Medicinalibus Indorum Herbis or Badianus manuscript, a fifteenth century Aztec herbal. Together with the presence of atacamite in the paint, they argue that the plants were from Colonial New Spain and represented the Nahuatl language, and date the manuscript to between 1521 (the date of the Conquest) and c. 1576, in contradiction of radiocarbon dating evidence of the vellum and many other elements of the manuscript. The analysis has been criticized by other Voynich Manuscript researchers, pointing out that—among other things—a skilled forger could construct plants that have a passing resemblance to theretofore undiscovered existing plants.

text: In 2014, Arthur O. Tucker and Rexford H. Talbert published a paper claiming a positive identification of 37 plants, 6 animals, and 1 mineral referenced in the manuscript to plant drawings in the

entity_name: Libellus de Medicinalibus Indorum Herbis

text: Libellus de Medicinalibus Indorum Herbis

text: or Badianus manuscript, a fifteenth century Aztec herbal. Together with the presence of atacamite in the paint, they argue that the plants were from Colonial

text: New Spain

text: and represented the

text: Nahuatl

text: language, and date the manuscript to between 1521 (the date of the Conquest) and c. 1576, in contradiction of radiocarbon dating evidence of the vellum and many other elements of the manuscript. The analysis has been criticized by other Voynich Manuscript researchers, pointing out that—among other things—a skilled forger could construct plants that have a passing resemblance to theretofore undiscovered existing plants.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains and artifacts

answers: NDQ_005715

answers: radiocarbon dating

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: skilled forger could construct plants that have a passing resemblance to theretofore undiscovered existing plants

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: things—a skilled forger

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: In refutation of young Earth claims of inconstant decay rates affecting the reliability of radiometric dating, Roger C. Wiens, a physicist specializing in isotope dating states:

text: In refutation of young Earth claims of inconstant decay rates affecting the reliability of radiometric dating, Roger C. Wiens, a physicist specializing in isotope dating states:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: inconstant decay rates

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays at a constant rate

answers: NDQ_005715

answers: isotope dating

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: isotope

answers: NDQ_005718

answers: inconstant decay rates

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: inconstant decay rates

answers: NDQ_005712

answers: young Earth claims of inconstant decay rates

answers: NDQ_005713

answers: inconstant decay rates

answers: NDQ_005714

answers: inconstant decay rates affecting the reliability of radiometric dating,

answers: NDQ_005715

answers: inconstant decay rates

answers: NDQ_005716

answers: inconstant decay rates

answers: NDQ_005717

answers: inconstant decay rates

answers: NDQ_005718

answers: inconstant decay rates

answers: NDQ_005719

answers: inconstant decay rates affecting the reliability of radiometric dating,

answers: NDQ_005720

answers: inconstant decay rates affecting the reliability of radiometric dating,

text: The rock's age of formation has been estimated to be approximately 3.29 ± 0.05 billion years from Rb-Sr radiometric dating.

text: The rock's age of formation has been estimated to be approximately 3.29 ± 0.05 billion years from

text: Rb

text: Sr

text: radiometric dating

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Rb-Sr

answers: NDQ_005718

answers: 0.05 billion years

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Rb-Sr

answers: NDQ_005712

answers: Rb-Sr

answers: NDQ_005713

answers: Rb-Sr radiometric dating.

answers: NDQ_005714

answers: Rb-Sr radiometric dating.

answers: NDQ_005715

answers: 3.29 <unk> 0.05 billion years

answers: NDQ_005716

answers: Rb-Sr radiometric dating.

answers: NDQ_005717

answers: 3.29 <unk> 0.05 billion years

answers: NDQ_005718

answers: The rock's age of formation

answers: NDQ_005719

answers: Rb-Sr radiometric dating.

answers: NDQ_005720

answers: Rb-Sr radiometric dating.

text: During the early 1990s, it became obvious with an increasing number of high-resolution radiocarbon dates associated with the Younger Dryas that this distinct paleoclimatic period is very difficult to date in detail using radiocarbon dating. Radiocarbon dating of samples on either side of the Allerød–Younger Dryas Boundary yielded dates that exhibited a very rapid age shift. Typically, they jump from 11,000 radiocarbon years BP to 10,700–10,600 radiocarbon years BP at the boundary. The 11,000 radiocarbon years BP dates clearly pre-dates the boundary. The first (oldest) overlying Younger Dryas radiocarbon samples often yielded ages of 10,700–10,600 radiocarbon years BP without any evidence of either an intervening unconformity or other evidence of erosion or nondeposition. Radiocarbon dates of terrestrial macrofossils and tree rings in Europe show that this decline in apparent radiocarbon age occurred over about a 50-year period. For the Younger Dryas–Preboreal transition, high-resolution dating of identified plant macrofossils yielded dates that fall within so-called radiocarbon plateau, i.e., a 200- to 250-year-long period when radiocarbon dating yields dates that are all roughly the same. As a result, the end of Younger Dryas can at best can only be estimated to have occurred sometime about 10,000–10,050 radiocarbon years BP.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: radiocarbon is a non-radioactive element

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: Carbon dating measures when the organism died because only then does

answers: NDQ_005717

answers: Radiocarbon dating yields dates that are all roughly the same

answers: NDQ_005718

answers: difficult to date in detail using radiocarbon dating

answers: NDQ_005719

answers: Which of the following is not useful for very young materials?

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: without any evidence of either an intervening unconformity

answers: NDQ_005713

answers: radiocarbon dating.

answers: NDQ_005714

answers: radiocarbon dating.

answers: NDQ_005715

answers: 10,700–10,600 radiocarbon years BP

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: 10,700–10,600 radiocarbon years BP

answers: NDQ_005718

answers: distinct paleoclimatic period is very difficult to date in detail

answers: NDQ_005719

answers: radiocarbon dating.

answers: NDQ_005720

answers: 10,700–10,600 radiocarbon years BP

text: Much of what was dug up in  has not survived. There was a lot of fatty material, probably from degraded body tissues, in the watery coffin which had dried  out. The bones were discoloured by the reaction of iron in the water with the tannin in the bark of the coffin and the skeleton was originally preserved by boiling it in glue in a laundry copper. This ruined any chance by present-day archaeologists to do a DNA study but collagen was able to be used from the skeleton for both dating and dietary isotope purposes. Several radiocarbon dates from the tree rings of the oak coffin and the composition of a ceremonial bronze dagger helped confirm the dating making this burial one of the best dated Early Bronze Age burials in Britain. Dendrochronological dating was attempted but the sequence remains floating until further finds from the period can be dated. Metallurgical and lead isotope analyses of the bronze dagger blade indicate that Ireland is likely to be the ultimate source of the copper ore used, but that it had been recycled with other ores being introduced. The original 1834 illustration of the blade appears to depict a scabbard that is no longer present. Scanning electron microscopy detected traces of animal collagen on the blade, confirming the former presence of a scabbard or sheath. The pommel of the dagger was fashioned from whalebone. The flint knife provided evidence of it having been hafted and re-sharpened twice. Microwear analysis indicated that it had been used to work hides and cut meat.

text: Much of what was dug up in  has not survived. There was a lot of fatty material, probably from degraded body tissues, in the watery coffin which had dried  out. The bones were discoloured by the reaction of iron in the water with the

text: tannin

text: in the bark of the coffin and the skeleton was originally preserved by boiling it in glue in a laundry copper. This ruined any chance by present-day archaeologists to do a

text: DNA

text: study but

text: collagen

text: was able to be used from the skeleton for both dating and dietary isotope purposes. Several radiocarbon dates from the tree rings of the oak coffin and the composition of a ceremonial bronze

text: dagger

text: helped confirm the dating making this burial one of the best dated Early Bronze Age burials in Britain. Dendrochronological dating was attempted but the sequence remains floating until further finds from the period can be dated. Metallurgical and lead isotope analyses of the bronze dagger blade indicate that Ireland is likely to be the ultimate source of the copper ore used, but that it had been recycled with other ores being introduced. The original 1834 illustration of the blade appears to depict a scabbard that is no longer present. Scanning electron microscopy detected traces of animal collagen on the blade, confirming the former presence of a scabbard or sheath. The pommel of the dagger was fashioned from whalebone. The flint knife provided evidence of it having been hafted and re-sharpened twice. Microwear analysis indicated that it had been used to work hides and cut meat.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: degraded body tissues

answers: NDQ_005717

answers: Several radiocarbon dates from the tree rings of the oak coffin

answers: NDQ_005718

answers: Dendrochronological dating

answers: NDQ_005719

answers: radiocarbon dates from the tree rings

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Early Bronze Age

answers: NDQ_005713

answers: The pommel of the dagger was fashioned from whalebone.

answers: NDQ_005714

answers: dietary isotope purposes.

answers: NDQ_005715

answers: whalebone.

answers: NDQ_005716

answers: DNA

answers: NDQ_005717

answers: collagen

answers: NDQ_005718

answers: DNA study

answers: NDQ_005719

answers: flint knife

answers: NDQ_005720

answers: copper ore

text: Inside the church at the west end is a gallery dated 1717 which also survived the fire.  It was planned to refurbish the church in 1873 but the full refurbishment did not occur. At the time the old box pews were replaced with the present pews and a two-manual organ was installed in the gallery.  Also inside the church are the royal arms of George III and six hatchments of the Lawton family.  At the base of a stairway leading to the gallery is the tomb of John Byber on which are carved his initials.  Displayed under the gallery are some 13th-century flooring tiles which were discovered during the 1874 restoration.  There is a ring of eight bells.  Five of these which are dated 1713 are by Richard Sanders; the other three are by John Taylor and Company, one of which is dated 1882 and the other two are dated 1901.  The parish registers start in 1559 and the churchwardens' accounts date from 1691.

text: Inside the church at the west end is a gallery dated 1717 which also survived the fire.  It was planned to refurbish the church in 1873 but the full refurbishment did not occur. At the time the old

text: box pew

text: s were replaced with the present pews and a two-

text: manual

text: organ was installed in the gallery.  Also inside the church are the

entity_name: Royal coat of arms of the United Kingdom

text: royal arms

text: of

text: George III

text: and six

text: hatchment

text: s of the Lawton family.  At the base of a stairway leading to the gallery is the tomb of John Byber on which are carved his initials.  Displayed under the gallery are some 13th-century flooring tiles which were discovered during the 1874

text: restoration

text: .  There is a

text: ring

text: of eight bells.  Five of these which are dated 1713 are by Richard Sanders; the other three are by

text: John Taylor and Company

text: , one of which is dated 1882 and the other two are dated 1901.  The

text: parish register

text: s start in 1559 and the

text: churchwarden

text: s' accounts date from 1691.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 13th-century

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 1717

answers: NDQ_005718

answers: the full refurbishment did not occur

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: 1713

answers: NDQ_005712

answers: 13th-century

answers: NDQ_005713

answers: 1717

answers: NDQ_005714

answers: 1717

answers: NDQ_005715

answers: 1882

answers: NDQ_005716

answers: 1717

answers: NDQ_005717

answers: 1717

answers: NDQ_005718

answers: survived the fire.

answers: NDQ_005719

answers: 1713

answers: NDQ_005720

answers: 1717

text: Where crystals such as zircon with uranium and thorium inclusions do not occur, a better, more inclusive, model of the data must be applied. Uranium-lead dating techniques have also been applied to other minerals such as calcite/aragonite and other carbonate minerals. These types of minerals often produce lower precision ages than igneous and metamorphic minerals traditionally used for age dating, but are more common in the geologic record.

text: Where crystals such as zircon with uranium and thorium inclusions do not occur, a better, more inclusive, model of the data must be applied. Uranium-lead dating techniques have also been applied to other minerals such as

text: calcite

text: aragonite

text: and other

text: carbonate mineral

text: s. These types of minerals often produce lower precision ages than

text: igneous

text: and

text: metamorphic

text: minerals traditionally used for age dating, but are more common in the geologic record.

answers: NDQ_005711

answers: Uranium

answers: NDQ_005712

answers: lower precision ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Uranium-lead

answers: NDQ_005715

answers: NDQ_005716

answers: carbonate minerals

answers: NDQ_005717

answers: zircon with uranium and thorium inclusions

answers: NDQ_005718

answers: lower precision ages

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium and thorium inclusions

answers: NDQ_005712

answers: lower precision ages

answers: NDQ_005713

answers: Uranium-lead dating techniques

answers: NDQ_005714

answers: lower precision ages

answers: NDQ_005715

answers: calcite/aragonite and other carbonate minerals.

answers: NDQ_005716

answers: carbonate minerals.

answers: NDQ_005717

answers: Uranium-lead

answers: NDQ_005718

answers: lower precision ages

answers: NDQ_005719

answers: calcite/aragonite and other carbonate minerals.

answers: NDQ_005720

answers: calcite/aragonite and other carbonate minerals.

text: Since the invention of Radiocarbon dating in 1949 scientists started to recognize various problems with radiocarbon dating from the labs to the samples being submitted. For instance the preliminary samples tested by Emory and Sinoto who raced to determine first contact had rather large standard deviations, reflecting the crude solid-carbon counting methods first used by the pioneers of the radiocarbon dating method. By late 1970's the most significant improvement by then was the use of accelerator mass spectrometry or AMS.

text: Since the invention of Radiocarbon dating in 1949 scientists started to recognize various problems with radiocarbon dating from the labs to the samples being submitted. For instance the preliminary samples tested by Emory and Sinoto who raced to determine first contact had rather large standard deviations, reflecting the crude solid-carbon counting methods first used by the pioneers of the radiocarbon dating method. By late 1970's the most significant improvement by then was the use of

text: accelerator mass spectrometry

text: or AMS.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: AMS

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: AMS

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: accelerator mass spectrometry

answers: NDQ_005718

answers: crude solid-carbon counting methods

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: crude solid-carbon

answers: NDQ_005713

answers: Radiocarbon dating

answers: NDQ_005714

answers: crude solid-carbon counting methods

answers: NDQ_005715

answers: AMS.

answers: NDQ_005716

answers: first contact had rather large standard deviations, reflecting the crude solid-carbon

answers: NDQ_005717

answers: first contact had rather large standard deviations,

answers: NDQ_005718

answers: crude solid-carbon counting methods

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: The calendar was abolished in the year XIV (1805). After this date, opinions seem to differ on the method by which the leap years would have been determined if the calendar were still in force. There are at least four hypotheses used to convert dates from the Gregorian calendar:

text: The calendar was abolished in the year XIV (1805). After this date, opinions seem to differ on the method by which the leap years would have been determined if the calendar were still in force. There are at least four hypotheses used to convert dates from the Gregorian calendar:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: argon is a noble gas

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: uranium-lead dating are useful for very young materials

answers: NDQ_005720

answers: NDQ_005711

answers: The calendar was abolished in the year XIV (1805).

answers: NDQ_005712

answers: The calendar was abolished in the year XIV

answers: NDQ_005713

answers: four hypotheses

answers: NDQ_005714

answers: The calendar was abolished in the year XIV (1805).

answers: NDQ_005715

answers: The calendar was abolished in the year XIV (1805).

answers: NDQ_005716

answers: The calendar was abolished in the year XIV

answers: NDQ_005717

answers: There are at least four hypotheses

answers: NDQ_005718

answers: opinions seem to differ on the method by which the leap years

answers: NDQ_005719

answers: The calendar was abolished in the year XIV (1805).

answers: NDQ_005720

answers: The calendar was abolished in the year XIV (1805).

text: With the advent of highly sensitive mass spectrometers, an application of Pa as a tracer in geology and paleoceanography has become possible. So, the ratio of protactinium-231 to thorium-230 is used for radiometric dating of sediments which are up to 175,000 years old and in modeling of the formation of minerals. In particular, its evaluation in oceanic sediments allowed to reconstruct the movements of North Atlantic water bodies during the last melting of Ice Age glaciers. Some of the protactinium-related dating variations rely on the analysis of the relative concentrations for several long-living members of the uranium decay chain – uranium, thorium and protactinium, for example. These elements have 6, 5 and 4 f-electrons in the outer shell and thus favor +6, +5 and +4 oxidation states, respectively, and show different physical and chemical properties. So, thorium and protactinium, but not uranium compounds are poorly soluble in aqueous solutions, and precipitate into sediments; the precipitation rate is faster for thorium than for protactinium. Besides, the concentration analysis for both protactinium-231 (half-life 32,760 years) and thorium-230 (half-life 75,380 years) allows to improve the accuracy compared to when only one isotope is measured; this double-isotope method is also weakly sensitive to inhomogeneities in the spatial distribution of the isotopes and to variations in their precipitation rate.

text: With the advent of highly sensitive

text: mass spectrometers

text: , an application of Pa as a tracer in geology and

text: paleoceanography

text: has become possible. So, the ratio of protactinium-231 to thorium-230 is used for

text: radiometric dating

text: of sediments which are up to 175,000 years old and in modeling of the formation of minerals. In particular, its evaluation in oceanic sediments allowed to reconstruct the movements of

text: North Atlantic

text: water bodies during the last melting of

text: Ice Age

text: glacier

text: s. Some of the protactinium-related dating variations rely on the analysis of the relative concentrations for several long-living members of the uranium decay chain – uranium, thorium and protactinium, for example. These elements have 6, 5 and 4 f-electrons in the outer shell and thus favor +6, +5 and +4 oxidation states, respectively, and show different physical and chemical properties. So, thorium and protactinium, but not uranium compounds are poorly soluble in aqueous solutions, and precipitate into sediments; the precipitation rate is faster for thorium than for protactinium. Besides, the concentration analysis for both protactinium-231 (half-life 32,760 years) and thorium-230 (half-life 75,380 years) allows to improve the accuracy compared to when only one isotope is measured; this double-isotope method is also weakly sensitive to inhomogeneities in the spatial distribution of the isotopes and to variations in their precipitation rate.

answers: NDQ_005711

answers: ratio of protactinium-231 to thorium-230

answers: NDQ_005712

answers: sediments which are up to 175,000 years old and in modeling of the formation of minerals

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating of sediments which are up to 175,000 years old

answers: NDQ_005715

answers: protactinium-231

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: ratio of protactinium-231 to thorium-230

answers: NDQ_005718

answers: weakly sensitive to inhomogeneities

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: protactinium-231 to thorium-230

answers: NDQ_005712

answers: up to 175,000 years old

answers: NDQ_005713

answers: thorium than for protactinium.

answers: NDQ_005714

answers: aqueous solutions, and precipitate into sediments;

answers: NDQ_005715

answers: protactinium.

answers: NDQ_005716

answers: uranium decay chain

answers: NDQ_005717

answers: protactinium-231 to thorium-230

answers: NDQ_005718

answers: inhomogeneities

answers: NDQ_005719

answers: compounds are poorly soluble in aqueous solutions,

answers: NDQ_005720

answers: protactinium-231

text: Radiocarbon dating is a dating method that uses the naturally occurring radioisotope carbon-14 (14C) to determine the age of carbonaceous materials up to about 60,000 years. In 1949, Willard F. Libby invented the procedure for carbon-14 dating.

text: Radiocarbon dating is a dating method that uses the naturally occurring radioisotope carbon-14 (14C) to determine the age of carbonaceous materials up to about 60,000 years. In 1949,

text: Willard F. Libby

text: invented the procedure for carbon-14 dating.

answers: NDQ_005711

answers: radioisotope

answers: NDQ_005712

answers: carbonaceous

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: 14C is naturally occurring

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: can be used to determine the age of carbonaceous materials

answers: NDQ_005718

answers: 60,000 years

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioisotope carbon-14

answers: NDQ_005712

answers: 60,000 years.

answers: NDQ_005713

answers: Radiocarbon dating

answers: NDQ_005714

answers: to determine the age of carbonaceous materials up to about 60,000 years.

answers: NDQ_005715

answers: 60,000 years.

answers: NDQ_005716

answers: carbon-14 (14C) to determine the age of carbonaceous materials

answers: NDQ_005717

answers: carbon-14 (14C) to determine the age of carbonaceous materials

answers: NDQ_005718

answers: 60,000 years.

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: 60,000 years.

text: The Outer Deposits have been dated to around 1.0 million years old based on the size of porcupines recovered. The Inner Deposits have been dated to greater than 70,000 years using radiometric techniques.

text: The Outer Deposits have been dated to around 1.0 million years old based on the size of porcupines recovered. The Inner Deposits have been dated to greater than 70,000 years using radiometric techniques.

answers: NDQ_005711

answers: radiometric techniques

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric techniques

answers: NDQ_005718

answers: 1.0 million years old

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: size of porcupines recovered.

answers: NDQ_005712

answers: greater than 70,000 years

answers: NDQ_005713

answers: 70,000 years using radiometric techniques.

answers: NDQ_005714

answers: radiometric techniques.

answers: NDQ_005715

answers: 70,000 years using radiometric techniques.

answers: NDQ_005716

answers: radiometric techniques.

answers: NDQ_005717

answers: The Inner Deposits have been dated to greater than 70,000 years

answers: NDQ_005718

answers: size of porcupines recovered.

answers: NDQ_005719

answers: radiometric techniques.

answers: NDQ_005720

answers: 70,000 years using radiometric techniques.

text: Creationists claim that evolution relies on certain types of evidence that do not give reliable information about the past. For example, it is argued that radiometric dating technique of evaluating a material's age based on the radioactive decay rates of certain isotopes generates inconsistent and thus unreliable results. Radiocarbon dating based on the carbon-14 isotope has been particularly criticized. It is argued that radiometric decay relies on a number of unwarranted assumptions such as the principle of uniformitarianism, consistent decay rates, or rocks acting as closed systems. Such arguments have been dismissed by scientists on the grounds that independent methods have confirmed the reliability of radiometric dating as a whole; additionally, different radiometric dating methods and techniques have independently confirmed each other's results.

text: Creationists claim that evolution relies on certain types of evidence that do not give reliable information about the past. For example, it is argued that

text: radiometric dating

text: technique of evaluating a material's age based on the

text: radioactive decay

text: rates of certain

text: isotope

text: s generates inconsistent and thus unreliable results.

text: Radiocarbon dating

text: based on the

text: isotope has been particularly criticized. It is argued that radiometric decay relies on a number of unwarranted assumptions such as the principle of

text: uniformitarianism

text: , consistent decay rates, or rocks acting as

text: closed system

text: s. Such arguments have been dismissed by scientists on the grounds that independent methods have confirmed the reliability of radiometric dating as a whole; additionally, different radiometric dating methods and techniques have independently confirmed each other's results.

answers: NDQ_005711

answers: radioactive decay rates of certain isotopes

answers: NDQ_005712

answers: unwarranted assumptions

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: unreliable results

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: independently confirmed each other's results

answers: NDQ_005718

answers: unreliable results

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: radioactive decay rates of certain isotopes

answers: NDQ_005712

answers: radioactive decay rates of certain isotopes

answers: NDQ_005713

answers: radioactive decay rates of certain isotopes

answers: NDQ_005714

answers: Radiocarbon dating

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: carbon-14 isotope

answers: NDQ_005717

answers: radioactive decay rates

answers: NDQ_005718

answers: inconsistent and thus unreliable results.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: The spent fuel is primarily composed of uranium, most of which has not been consumed or transmuted in the nuclear reactor. At a typical concentration of around 96% by mass in the used nuclear fuel, uranium is the largest component of used nuclear fuel.  The composition of reprocessed uranium depends on the time the fuel has been in the reactor, but it is mostly uranium-238, with about 1% uranium-235, 1% uranium-236 and smaller amounts of other isotopes including uranium-232.  However, reprocessed uranium is also a waste product because it is contaminated and undesirable for reuse in reactors.  During its irradiation in a reactor, uranium is profoundly modified. The uranium that leaves the reprocessing plant contains all the isotopes of uranium between uranium-232 and uranium-238 except uranium-237, which is rapidly transformed into neptunium-237. The undesirable isotopic contaminants are:

text: The spent fuel is primarily composed of uranium, most of which has not been consumed or transmuted in the nuclear reactor. At a typical concentration of around 96% by mass in the used nuclear fuel, uranium is the largest component of used nuclear fuel.  The composition of reprocessed uranium depends on the time the fuel has been in the reactor, but it is mostly

text: , with about 1%

text: , 1%

text: and smaller amounts of other isotopes including

text: .  However, reprocessed uranium is also a waste product because it is contaminated and undesirable for reuse in reactors.  During its irradiation in a reactor, uranium is profoundly modified. The uranium that leaves the reprocessing plant contains all the isotopes of uranium between

text: and

text: except

text: , which is rapidly transformed into

text: . The undesirable isotopic contaminants are:

answers: NDQ_005711

answers: irradiation

answers: NDQ_005712

answers: neptunium

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 is a stable isotope

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: uranium-238

answers: NDQ_005718

answers: uranium is profoundly modified

answers: NDQ_005719

answers: The composition of reprocessed uranium depends on the time the fuel has been in the reactor

answers: NDQ_005720

answers: NDQ_005711

answers: irradiation

answers: NDQ_005712

answers: uranium-232 and uranium-238

answers: NDQ_005713

answers: uranium-237,

answers: NDQ_005714

answers: uranium-237,

answers: NDQ_005715

answers: uranium-237,

answers: NDQ_005716

answers: uranium-237,

answers: NDQ_005717

answers: uranium-237,

answers: NDQ_005718

answers: reprocessed uranium is also a waste product

answers: NDQ_005719

answers: uranium-237,

answers: NDQ_005720

answers: uranium-237,

text: An issue date was added, and cheques may not be valid a certain amount of time after issue.  In the US and Canada a cheque is typically valid for six months after the date of issue, after which it is a stale-dated cheque, but this depends on where the cheque is drawn; in Australia this is typically fifteen months.  A cheque that has an issue date in the future, a post-dated cheque, may not be able to be presented until that date has passed, writing a post dated cheque may simply be ignored or is illegal in some countries. Conversely, an antedated cheque has an issue date in the past.

text: An issue date was added, and cheques may not be valid a certain amount of time after issue.  In the US and Canada a cheque is typically valid for six months after the date of issue, after which it is a

text: stale-dated cheque

text: , but this depends on where the cheque is drawn; in Australia this is typically fifteen months.  A cheque that has an issue date in the future, a

text: post-dated cheque

text: , may not be able to be presented until that date has passed, writing a post dated cheque may simply be ignored or is illegal in some countries. Conversely, an

text: antedated cheque

text: has an issue date in the past.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: stale-dated

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: stale-dated

answers: NDQ_005718

answers: a cheque that has an issue date in the future

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: antedated cheque

answers: NDQ_005712

answers: antedated cheque has an issue date in the past.

answers: NDQ_005713

answers: antedated cheque

answers: NDQ_005714

answers: antedated cheque has an issue date in the past.

answers: NDQ_005715

answers: antedated cheque

answers: NDQ_005716

answers: antedated cheque has an issue date in the past.

answers: NDQ_005717

answers: antedated cheque has an issue date in the past.

answers: NDQ_005718

answers: cheques may not be valid a certain amount of time after issue.

answers: NDQ_005719

answers: antedated cheque

answers: NDQ_005720

answers: antedated cheque

text: To obtain a filing date, the documents filed must comply with the regulations of the patent office in which it was filed. A full specification complying with all rules may not be required to obtain a filing date. For example, in the U.K., claims and an abstract are not required to obtain a filing date, but can be added later. However, since no subject matter can be added to an application after the filing date, it is important that an application disclose all material relevant to the application at the time of filing. If the requirements for the award of a filing date are not met, the patent office will notify the applicant of the deficiencies. Depending upon the law of the patent office in question, correction may be possible without moving the filing date, or the application may be awarded a filing date adjusted to the date on which the requirements are completed.

text: To obtain a filing date, the documents filed must comply with the regulations of the patent office in which it was filed. A full specification complying with all rules may not be required to obtain a filing date. For example, in the U.K., claims and an abstract are not required to obtain a filing date, but can be added later. However, since no subject matter can be added to an application after the filing date, it is important that an application disclose all material relevant to the application at the time of filing. If the requirements for the award of a filing date are not met, the patent office will notify the applicant of the deficiencies. Depending upon the law of the patent office in question, correction may be possible without moving the filing date, or the application may be awarded a filing date adjusted to the date on which the requirements are completed.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for these materials

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: are not required to obtain a filing date

answers: NDQ_005718

answers: no subject matter can be added to an application after the filing date

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: To obtain a filing date,

answers: NDQ_005712

answers: no subject matter can be added to an application after the filing date,

answers: NDQ_005713

answers: To obtain a filing date,

answers: NDQ_005714

answers: filing date,

answers: NDQ_005715

answers: To obtain a filing date,

answers: NDQ_005716

answers: filing date,

answers: NDQ_005717

answers: claims and an abstract are not required to obtain a filing date,

answers: NDQ_005718

answers: no subject matter can be added to an application after the filing date,

answers: NDQ_005719

answers: To obtain a filing date,

answers: NDQ_005720

answers: To obtain a filing date,

text: Pleistocene activity has been dated 270,000 years ago for a sample south of Cerro Ticsho and 500,000 years for another south of the Yanamauras cones. These dates are derived from potassium-argon dating.

text: Pleistocene

text: activity has been dated 270,000 years ago for a sample south of

text: Cerro Ticsho

text: and 500,000 years for another south of the Yanamauras cones. These dates are derived from

text: potassium-argon dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: 500,000 years

answers: NDQ_005718

answers: potassium-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon dating.

answers: NDQ_005713

answers: potassium-argon dating.

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: These dates

answers: NDQ_005718

answers: potassium-argon

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: potassium-argon dating.

text: The structures have been dated by uranium series dating as 176.5 (±2.1) thousand years old, with 2σ uncertainties (95.5% probability). There are two annular structures, one 6.7 by 4.5 metres, and the other 2.2 by 2.1 metres, composed of one to four aligned layers of stalagmites, with some small pieces placed inside the layers to support them. Some stalagmites were placed vertically against the rings, possibly as reinforcement. There are also four stacks of stalagmites between 0.55 and 2.60 metres in diameter, two of which were inside the large ring and two outside it. Around 400 stalagmite pieces (called "speleofacts" by the researchers) were used, with a total length of 112.4 metres and weight of around 2.2 tons.

text: The structures have been dated by

text: uranium series dating

text: as 176.5 (±2.1) thousand years old, with

text: 2σ

text: uncertainties (95.5% probability). There are two annular structures, one 6.7 by 4.5 metres, and the other 2.2 by 2.1 metres, composed of one to four aligned layers of stalagmites, with some small pieces placed inside the layers to support them. Some stalagmites were placed vertically against the rings, possibly as reinforcement. There are also four stacks of stalagmites between 0.55 and 2.60 metres in diameter, two of which were inside the large ring and two outside it. Around 400 stalagmite pieces (called "speleofacts" by the researchers) were used, with a total length of 112.4 metres and weight of around 2.2 tons.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: NDQ_005714

answers: uranium series

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: uranium series dating

answers: NDQ_005718

answers: 2 uncertainties

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium series dating

answers: NDQ_005712

answers: 176.5 (<unk>2.1) thousand years old,

answers: NDQ_005713

answers: 176.5 (<unk>2.1) thousand years old,

answers: NDQ_005714

answers: uranium

answers: NDQ_005715

answers: 176.5 (<unk>2.1) thousand years old,

answers: NDQ_005716

answers: uranium

answers: NDQ_005717

answers: uranium series

answers: NDQ_005718

answers: 2<unk> uncertainties

answers: NDQ_005719

answers: uranium series dating

answers: NDQ_005720

answers: 176.5 (<unk>2.1) thousand years old,

text: Tritium was first produced in 1934 from deuterium, another isotope of hydrogen, by Ernest Rutherford, Mark Oliphant, and Paul Harteck. However, their experiment could not isolate tritium, which was later accomplished by Luis Alvarez and Robert Cornog, who also realized tritium's radioactivity. Willard F. Libby recognized that tritium could be used for radiometric dating of water and wine.

text: Tritium was first produced in 1934 from

text: deuterium

text: , another isotope of hydrogen, by

text: Ernest Rutherford

text: Mark Oliphant

text: , and

text: Paul Harteck

text: . However, their experiment could not isolate tritium, which was later accomplished by

text: Luis Alvarez

text: and

text: Robert Cornog

text: , who also realized tritium's radioactivity.

text: Willard F. Libby

text: recognized that tritium could be used for

text: radiometric dating

text: of water and

text: wine

answers: NDQ_005711

answers: tritium

answers: NDQ_005712

answers: tritium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: tritium was first produced in 1934

answers: NDQ_005715

answers: NDQ_005716

answers: Tritium

answers: NDQ_005717

answers: tritium could be used for radiometric dating of water and wine

answers: NDQ_005718

answers: tritium's radioactivity

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactivity.

answers: NDQ_005712

answers: water and wine.

answers: NDQ_005713

answers: Tritium

answers: NDQ_005714

answers: Tritium

answers: NDQ_005715

answers: Tritium was first produced in 1934 from deuterium,

answers: NDQ_005716

answers: Tritium

answers: NDQ_005717

answers: tritium could be used for radiometric dating of water and wine.

answers: NDQ_005718

answers: experiment could not isolate tritium,

answers: NDQ_005719

answers: tritium could be used for radiometric dating of water and wine.

answers: NDQ_005720

answers: Tritium

text: The Lamar River Formation is part of the Absaroka Volcanic Supergroup. It is a thick accumulation of volcanic rocks that were either erupted from or eroded from the slopes of two belts of Eocene stratovolcanoes. These rocks accumulated within an intermountain basin between these belts. Before they were destroyed by erosion, these volcanoes are estimated to have had peaks that rose about  to  above adjacent intermountain valleys. Depending on location, the Lamar River Formation unconformably overlies either older lavas, conglomerates, tuffs, volcanic breccias of the Sepulcher Formation; Mississippian limestones and dolomites; or Precambrian gneiss. Based on radiometric dates and plant fossils from it, the Lamar River Formation is considered to be of Middle Eocene age.

text: The Lamar River Formation is part of the Absaroka Volcanic Supergroup. It is a thick accumulation of volcanic rocks that were either erupted from or eroded from the slopes of two belts of Eocene stratovolcanoes. These rocks accumulated within an intermountain basin between these belts. Before they were destroyed by erosion, these volcanoes are estimated to have had peaks that rose about  to  above adjacent intermountain valleys. Depending on location, the Lamar River Formation

text: unconformably

text: overlies either older

text: lava

text: s, conglomerates, tuffs, volcanic breccias of the Sepulcher Formation;

text: Mississippian

text: limestone

text: s and

text: dolomite

text: s; or

text: Precambrian

text: gneiss

text: . Based on radiometric dates and plant fossils from it, the Lamar River Formation is considered to be of Middle Eocene age.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: Middle Eocene

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dates and plant fossils from it

answers: NDQ_005718

answers: plant fossils

answers: NDQ_005719

answers: What is the Lamar River Formation?

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: plant fossils

answers: NDQ_005712

answers: Middle Eocene

answers: NDQ_005713

answers: Middle Eocene

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: Absaroka Volcanic Supergroup.

answers: NDQ_005716

answers: radiometric dates

answers: NDQ_005717

answers: Middle Eocene age.

answers: NDQ_005718

answers: Middle Eocene age.

answers: NDQ_005719

answers: radiometric dates

answers: NDQ_005720

answers: radiometric dates

text: Other methods of radiometric dating are also available, that are based on slightly or largely different principles, but always rely on the phenomenon of radioactive decay. These alternative radiometric methods are:

text: Other methods of

text: radiometric dating

text: are also available, that are based on slightly or largely different principles, but always rely on the phenomenon of

text: radioactive decay

text: . These alternative radiometric methods are:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 decays at a constant rate

answers: NDQ_005715

answers: carbon-14 decays to carbon-12 with a half-life of 5,730 years

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: radioactive decay

answers: NDQ_005718

answers: rely on the phenomenon of radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radioactive decay.

answers: NDQ_005712

answers: radioactive decay.

answers: NDQ_005713

answers: radioactive decay.

answers: NDQ_005714

answers: radioactive decay.

answers: NDQ_005715

answers: Other methods of radiometric dating

answers: NDQ_005716

answers: radioactive decay.

answers: NDQ_005717

answers: radioactive decay.

answers: NDQ_005718

answers: always rely on the phenomenon of radioactive decay.

answers: NDQ_005719

answers: radioactive decay.

answers: NDQ_005720

answers: radioactive decay.

text: Radiometric dating continues to be the predominant way scientists date geologic timescales. Techniques for radioactive dating have been tested and fine-tuned on an ongoing basis since the 1960s.  Forty or so different dating techniques have been utilized to date, working on a wide variety of materials. Dates for the same sample using these different techniques are in very close agreement on the age of the material.

text: Radiometric dating

text: continues to be the predominant way scientists date geologic timescales. Techniques for radioactive dating have been tested and fine-tuned on an ongoing basis since the 1960s.  Forty or so different dating techniques have been utilized to date, working on a wide variety of materials. Dates for the same sample using these different techniques are in very close agreement on the age of the material.

answers: NDQ_005711

answers: radioactive

answers: NDQ_005712

answers: unanswerable

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: 5.730 years

answers: NDQ_005716

answers: radioactive dating

answers: NDQ_005717

answers: date for the same sample using these different dating techniques

answers: NDQ_005718

answers: Forty or so different dating techniques have been utilized to date

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Dates for the same sample using these different techniques are in very close agreement

answers: NDQ_005712

answers: in very close agreement on the age of the material.

answers: NDQ_005713

answers: Radiometric dating

answers: NDQ_005714

answers: in very close agreement on the age of the material.

answers: NDQ_005715

answers: Radiometric dating

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: in very close agreement on the age of the material.

answers: NDQ_005718

answers: different techniques are in very close agreement on the age of the material.

answers: NDQ_005719

answers: Dates for the same sample using these different techniques are in very close agreement

answers: NDQ_005720

answers: Radiometric dating

text: Rb has a half-life of 4.92×10 years. It readily substitutes for potassium in minerals, and is therefore fairly widespread. Rb has been used extensively in dating rocks; Rb decays to stable strontium-87 by emission of a negative beta particle. During fractional crystallization, Sr tends to become concentrated in plagioclase, leaving Rb in the liquid phase. Hence, the Rb/Sr ratio in residual magma may increase over time, resulting in rocks with increasing Rb/Sr ratios with increasing differentiation. Highest ratios (10 or higher) occur in pegmatites. If the initial amount of Sr is known or can be extrapolated, the age can be determined by measurement of the Rb and Sr concentrations and the Sr/Sr ratio. The dates indicate the true age of the minerals only if the rocks have not been subsequently altered. See rubidium-strontium dating for a more detailed discussion.

text: Rb has a

text: half-life

text: of 4.92×10 years. It readily substitutes for

text: potassium

text: in

text: mineral

text: s, and is therefore fairly widespread. Rb has been used extensively in

text: dating rocks

text: ; Rb decays to stable

text: strontium

text: -87 by emission of a negative

text: beta particle

text: . During

text: fractional crystallization

text: , Sr tends to become concentrated in

text: plagioclase

text: , leaving Rb in the liquid phase. Hence, the Rb/Sr ratio in residual

text: magma

text: may increase over time, resulting in rocks with increasing Rb/Sr ratios with increasing

text: differentiation

text: . Highest ratios (10 or higher) occur in

text: pegmatite

text: s. If the initial amount of Sr is known or can be extrapolated, the age can be determined by measurement of the Rb and Sr concentrations and the Sr/Sr ratio. The dates indicate the true age of the minerals only if the rocks have not been subsequently altered. See

text: rubidium-strontium dating

text: for a more detailed discussion.

answers: NDQ_005711

answers: rubidium-strontium dating

answers: NDQ_005712

answers: minerals have not been subsequently altered

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: rubidium-strontium dating

answers: NDQ_005715

answers: NDQ_005716

answers: rubidium-strontium dating

answers: NDQ_005717

answers: Rb has been used extensively in dating rocks;

answers: NDQ_005718

answers: only if the rocks have not been subsequently altered

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: measurement of the Rb and Sr concentrations

answers: NDQ_005712

answers: if the rocks have not been subsequently altered.

answers: NDQ_005713

answers: rubidium-strontium dating

answers: NDQ_005714

answers: rubidium-strontium dating

answers: NDQ_005715

answers: strontium-87

answers: NDQ_005716

answers: if the rocks have not been subsequently altered.

answers: NDQ_005717

answers: Rb decays to stable strontium-87

answers: NDQ_005718

answers: if the rocks have not been subsequently altered.

answers: NDQ_005719

answers: rubidium-strontium dating

answers: NDQ_005720

answers: rubidium-strontium dating

text: Similarities between partners’ goals will more likely lead to a more successful first date. And if a first date goes well, the individuals might engage in other activities, such as a second date. If partners’ goals and expectations are similar, it makes it easier for both to have a good time and be comfortable around each other. For example, if both a man and a woman are looking for friendship then both can focus on becoming friends and not worry about if the other person is trying to make a move and having to decide how to accept or reject the offer. On the other hand, having different goals can sometimes make a situation awkward or uncomfortable.

text: Similarities between partners’ goals will more likely lead to a more successful first date. And if a first date goes well, the individuals might engage in other activities, such as a second date. If partners’ goals and expectations are similar, it makes it easier for both to have a good time and be comfortable around each other. For example, if both a man and a woman are looking for friendship then both can focus on becoming friends and not worry about if the other person is trying to make a move and having to decide how to accept or reject the offer. On the other hand, having different goals can sometimes make a situation awkward or uncomfortable.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: if partners’ goals and expectations are similar then both can focus on becoming friends

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Similarities between partners’ goals

answers: NDQ_005712

answers: similar,

answers: NDQ_005713

answers: different goals

answers: NDQ_005714

answers: Similarities between partners’ goals

answers: NDQ_005715

answers: different goals

answers: NDQ_005716

answers: Similarities between partners’ goals

answers: NDQ_005717

answers: different goals can sometimes make a situation awkward or uncomfortable.

answers: NDQ_005718

answers: having different goals can sometimes make a situation awkward or uncomfortable.

answers: NDQ_005719

answers: different goals

answers: NDQ_005720

answers: different goals

text: Lead singer Pete Murray, in December 2009, reported via his Twitter account that he was listening to the album masters, hinting that the album was done or very close to it. In mid-February their official website read "Almost There. Almost" and then in early March its release date of May 25, 2010 was announced.  However, Lo-Pro's official site changed from showing the date "5.25.10" to "6.08.2010", hinting that the release date has changed. Shortly after this, it was confirmed to be delayed to June 8, 2010.

text: Lead singer

text: Pete Murray

text: , in December 2009, reported via his Twitter account that he was listening to the album masters, hinting that the album was done or very close to it. In mid-February their official website read "Almost There. Almost" and then in early March its release date of May 25, 2010 was announced.  However, Lo-Pro's official site changed from showing the date "5.25.10" to "6.08.2010", hinting that the release date has changed. Shortly after this, it was confirmed to be delayed to June 8, 2010.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: isotopes

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: listening to the album masters,

answers: NDQ_005712

answers: 2009,

answers: NDQ_005713

answers: June 8, 2010.

answers: NDQ_005714

answers: Lead singer Pete Murray, in December 2009,

answers: NDQ_005715

answers: May 25, 2010

answers: NDQ_005716

answers: album masters,

answers: NDQ_005717

answers: "5.25.10"

answers: NDQ_005718

answers: album masters,

answers: NDQ_005719

answers: Lead singer Pete Murray, in December 2009,

answers: NDQ_005720

answers: Lead singer Pete Murray, in December 2009,

text: The deuterium lamp emits radiation extending from 112 nm to 900 nm, although its continuous spectrum is only from 180 nm to 370 nm. The spectrum intensity does not actually decrease from 250 nm to 300 nm as shown in the spectrum plot above. The decrease in the plot is due to decreased efficiency at low wavelengths of the photo detector used to measure the lamp intensity. The deuterium lamp's continuous spectrum is useful as both a reference in UV radiometric work and to generate a signal in various photometric devices.

text: The deuterium lamp emits radiation extending from 112 nm to 900 nm, although its continuous spectrum is only from 180 nm to 370 nm. The spectrum intensity does not actually decrease from 250 nm to 300 nm as shown in the spectrum plot above. The decrease in the plot is due to decreased efficiency at low wavelengths of the photo detector used to measure the lamp intensity. The deuterium lamp's continuous spectrum is useful as both a reference in UV radiometric work and to generate a signal in various photometric devices.

answers: NDQ_005711

answers: UV

answers: NDQ_005712

answers: deuterium

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The decrease in the plot is due to decreased efficiency at low wavelengths of the photo detector used to measure the lamp intensity

answers: NDQ_005718

answers: efficiency at low wavelengths of the photo detector

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: UV radiometric work

answers: NDQ_005712

answers: decreased efficiency at low wavelengths

answers: NDQ_005713

answers: 180 nm to 370 nm.

answers: NDQ_005714

answers: The deuterium

answers: NDQ_005715

answers: The deuterium lamp

answers: NDQ_005716

answers: The deuterium lamp

answers: NDQ_005717

answers: 250 nm to 300 nm

answers: NDQ_005718

answers: decreased efficiency at low wavelengths

answers: NDQ_005719

answers: The deuterium lamp

answers: NDQ_005720

answers: 900 nm,

text: For an introduction to the radiocarbon dating techniques used by archaeologists and geologists, see radiocarbon dating.

text: For an introduction to the radiocarbon dating techniques used by archaeologists and geologists, see

text: radiocarbon dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: carbon is a non-reactive element

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: radiocarbon dating

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon dating.

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: Prior to 17.5 million years ago, the Western Cascade Stratovolcanoes erupted with periodic regularity for over 20 million years, even as they do today.  An abrupt transition to shield volcanic flooding took place in the mid-Miocene. The flows can be divided into four major categories: The Steens Basalt, Grande Ronde Basalt, the Wanapum Basalt, and the Saddle Mountains Basalt. The various lava flows have been dated by radiometric dating—particularly through measurement of the ratios of isotopes of potassium to argon. The Columbia River flood basalt province comprises more than 300 individual basalt lava flows that have an average volume of .

text: Prior to 17.5 million years ago, the Western

text: Cascade

text: Stratovolcano

text: es erupted with periodic regularity for over 20 million years, even as they do today.  An abrupt transition to

text: shield volcanic

text: flooding took place in the mid-Miocene. The flows can be divided into four major categories: The Steens Basalt, Grande Ronde Basalt, the Wanapum Basalt, and the Saddle Mountains Basalt. The various lava flows have been dated by radiometric dating—particularly through measurement of the ratios of isotopes of potassium to argon. The Columbia River flood basalt province comprises more than 300 individual basalt lava flows that have an average volume of .

answers: NDQ_005711

answers: measurement of the ratios of isotopes

answers: NDQ_005712

answers: potassium to argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium to argon

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: ratios of isotopes of potassium to argon

answers: NDQ_005718

answers: isotopes of potassium to argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: ratios of isotopes of potassium to argon.

answers: NDQ_005712

answers: ratios of isotopes of potassium to argon.

answers: NDQ_005713

answers: ratios of isotopes of potassium to argon.

answers: NDQ_005714

answers: radiometric dating—particularly

answers: NDQ_005715

answers: 20 million years,

answers: NDQ_005716

answers: radiometric dating—particularly

answers: NDQ_005717

answers: ratios of isotopes

answers: NDQ_005718

answers: ratios of isotopes of potassium to argon.

answers: NDQ_005719

answers: radiometric dating—particularly

answers: NDQ_005720

answers: radiometric dating—particularly

text: The uranium-lead dating of zircons from an ash bed in the Bass Formation, argon–argon dating of overlying igneous rocks, and thermochronologic studies of the underling Vishnu Basement Rocks constrain the age of the Bass Formation and associated Unkar Group. Zircons from air-fallen, volcanic ash beds in its lower part yielded a uranium-lead date of 1,254.8 ± 1.6 Ma. This date is consistent with radiometric ages of Precambrian strata interpreted to be correlative with the Bass Formation and its age estimated from earlier paleomagentic studies. In addition, this date is consistent with the younger Cardenas Basalt having been erupted about 1,104 Ma. Finally, the uranium-lead dating of zircons is consistent with studies of the underlying Vishnu Basement Rocks that indicate they were exhumed from depths of 25 to 10 km depths between 1,750 and 1,660 Ma and from a depth of 10 km to the surface on which the Bass Formation lies between 1,660 and 1,250 Ma.

text: The

text: uranium-lead dating

text: of zircons from an ash bed in the Bass Formation,

text: argon–argon dating

text: of overlying

text: igneous

text: rocks, and thermochronologic studies of the underling Vishnu Basement Rocks constrain the age of the Bass Formation and associated Unkar Group. Zircons from air-fallen, volcanic ash beds in its lower part yielded a uranium-lead date of 1,254.8 ± 1.6 Ma. This date is consistent with radiometric ages of Precambrian strata interpreted to be correlative with the Bass Formation and its age estimated from earlier paleomagentic studies. In addition, this date is consistent with the younger Cardenas Basalt having been erupted about 1,104 Ma. Finally, the uranium-lead dating of zircons is consistent with studies of the underlying Vishnu Basement Rocks that indicate they were exhumed from depths of 25 to 10 km depths between 1,750 and 1,660 Ma and from a depth of 10 km to the surface on which the Bass Formation lies between 1,660 and 1,250 Ma.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: precambrian

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: argon–argon dating

answers: NDQ_005718

answers: uranium-lead dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: earlier paleomagentic studies.

answers: NDQ_005712

answers: Precambrian

answers: NDQ_005713

answers: uranium-lead dating

answers: NDQ_005714

answers: uranium-lead dating

answers: NDQ_005715

answers: Bass Formation,

answers: NDQ_005716

answers: age

answers: NDQ_005717

answers: argon–argon dating of overlying igneous rocks,

answers: NDQ_005718

answers: age estimated from earlier paleomagentic studies.

answers: NDQ_005719

answers: argon–argon

answers: NDQ_005720

answers: 1,254.8 <unk> 1.6 Ma.

text: Isochron dating is a common technique of radiometric dating and is applied to date certain events, such as crystallization, metamorphism, shock events, and differentiation of precursor melts, in the history of rocks. Isochron dating can be further separated into mineral isochron dating and whole rock isochron dating; both techniques are applied frequently to date terrestrial and also extraterrestrial rocks (meteorites). The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter nuclide in the radioactive decay sequence. Indeed, the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays.

text: Isochron dating is a common technique of

text: radiometric dating

text: and is applied to date certain events, such as

text: crystal

text: lization,

text: metamorphism

text: , shock events, and differentiation of precursor melts, in the history of

text: rocks

text: . Isochron dating can be further separated into mineral isochron dating and whole rock isochron dating; both techniques are applied frequently to date terrestrial and also extraterrestrial rocks (

text: meteorite

text: s). The advantage of isochron dating as compared to simple radiometric dating techniques is that no assumptions are needed about the initial amount of the daughter

text: nuclide

text: in the

text: radioactive decay

text: sequence. Indeed, the initial amount of the daughter product can be determined using isochron dating. This technique can be applied if the daughter element has at least one stable

text: isotope

text: other than the daughter isotope into which the parent nuclide decays.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: isochron dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: isochron dating is a common technique of radiometric dating

answers: NDQ_005715

answers: isochron dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: if the daughter element has at least one stable isotope other than the daughter isotope into which the parent nuclide decays

answers: NDQ_005718

answers: no assumptions are needed about the initial amount

answers: NDQ_005719

answers: not enough information

answers: NDQ_005720

answers: NDQ_005711

answers: radioactive decay sequence.

answers: NDQ_005712

answers: if the daughter element has at least one stable isotope

answers: NDQ_005713

answers: no assumptions are needed about the initial amount of the daughter nuclide

answers: NDQ_005714

answers: no assumptions are needed about the initial amount of the daughter nuclide

answers: NDQ_005715

answers: no assumptions are needed about the initial amount of the daughter nuclide

answers: NDQ_005716

answers: no assumptions are needed about the initial amount of the daughter nuclide

answers: NDQ_005717

answers: if the daughter element has at least one stable isotope

answers: NDQ_005718

answers: initial amount of the daughter nuclide in the radioactive decay sequence.

answers: NDQ_005719

answers: Isochron dating

answers: NDQ_005720

answers: Isochron dating

text: Baron Eduard von Toll was among the first to report in detail about the abundance of Pleistocene fossils found within Bolshoy Lyakhovsky Island. Under a peat composed of water mosses covering what he described as "perpetual ice", now known to be permafrost, Baron von Toll found fragments of willow and the bones of post-Neogene mammals, like the shoulder-bone of a saber-toothed tiger. He also reported having found in a frozen, sandy clay layer and lying on its side, a complete tree of Alnus fruticosa 15 to 20 ft (4.5 to 6 m) in length, including roots, with leaves and cones adhering. Unfortunately, his reports have been frequently either misrepresented or badly garbled by popular accounts of his findings. For example, various authors, i.e. Dr. Digby and Dr. Kropotkin misreport this tree as being  high. Other publications, i.e. Fingerprints of the Gods and Earth's Shifting Crust not only incorrectly state that this alder tree is  high, but also they also repeat fictional claims from unreliable sources that this tree was either a "fruit tree" or "plum tree" and had "green leaves"and green fruit" still attached. Lacking modern radiocarbon dating techniques, Baron von Toll assigned this tree and other fossils to single "mammoth period". As discussed above, more recent geologic research and radiometric dating of these fossils and the sediment containing them has found that they are from different layers of Middle to Late Pleistocene glacial and interglacial sediments.

text: Baron Eduard von Toll

text: was among the first to report in detail about the abundance of Pleistocene fossils found within Bolshoy Lyakhovsky Island. Under a peat composed of water mosses covering what he described as "perpetual ice", now known to be permafrost, Baron von Toll found fragments of willow and the bones of post-

text: Neogene

text: mammals, like the shoulder-bone of a

text: saber-toothed tiger

text: . He also reported having found in a frozen, sandy clay layer and lying on its side, a complete tree of Alnus fruticosa 15 to 20 ft (4.5 to 6 m) in length, including roots, with leaves and cones adhering. Unfortunately, his reports have been frequently either misrepresented or badly garbled by popular accounts of his findings. For example, various authors, i.e. Dr. Digby and Dr. Kropotkin misreport this tree as being  high. Other publications, i.e. Fingerprints of the Gods and Earth's Shifting Crust not only incorrectly state that this alder tree is  high, but also they also repeat fictional claims from unreliable sources that this tree was either a "fruit tree" or "plum tree" and had "green leaves"and green fruit" still attached. Lacking modern radiocarbon dating techniques, Baron von Toll assigned this tree and other fossils to single "

text: mammoth

text: period". As discussed above, more recent geologic research and radiometric dating of these fossils and the sediment containing them has found that they are from different layers of Middle to Late Pleistocene glacial and interglacial sediments.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: How long does carbon-14 decay?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Baron von Toll assigned this tree and other fossils to single "mammoth period

answers: NDQ_005718

answers: Lacking modern radiocarbon dating techniques

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Middle to Late Pleistocene

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: modern radiocarbon dating techniques,

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: Radiometric dating has been carried out since 1905 when it was invented by Ernest Rutherford as a method by which one might determine the age of the Earth. In the century since then the techniques have been greatly improved and expanded. Dating can now be performed on samples as small as a nanogram using a mass spectrometer. The mass spectrometer was invented in the 1940s and began to be used in radiometric dating in the 1950s. It operates by generating a beam of ionized atoms from the sample under test. The ions then travel through a magnetic field, which diverts them into different sampling sensors, known as "Faraday cups", depending on their mass and level of ionization. On impact in the cups, the ions set up a very weak current that can be measured to determine the rate of impacts and the relative concentrations of different atoms in the beams.

text: Radiometric dating has been carried out since 1905 when it was

text: invented

text: by

text: Ernest Rutherford

text: as a method by which one might determine the

text: age of the Earth

text: . In the century since then the techniques have been greatly improved and expanded. Dating can now be performed on samples as small as a nanogram using a

text: mass spectrometer

text: . The mass spectrometer was invented in the 1940s and began to be used in radiometric dating in the 1950s. It operates by generating a beam of

text: ionized atoms

text: from the sample under test. The ions then travel through a magnetic field, which diverts them into different sampling sensors, known as "

text: Faraday cup

text: s", depending on their mass and level of ionization. On impact in the cups, the ions set up a very weak current that can be measured to determine the rate of impacts and the relative concentrations of different atoms in the beams.

answers: NDQ_005711

answers: yes

answers: NDQ_005712

answers: mass spectrometer

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: mass spectrometer

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: On impact in the cups, the ions set up a very weak current

answers: NDQ_005718

answers: can now be performed on samples as small as a nanogram

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: generating a beam of ionized atoms

answers: NDQ_005712

answers: samples as small as a nanogram

answers: NDQ_005713

answers: Radiometric dating has been carried out since 1905

answers: NDQ_005714

answers: determine the age of the Earth.

answers: NDQ_005715

answers: Radiometric dating has been carried out since 1905

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: "Faraday cups",

answers: NDQ_005718

answers: samples as small as a nanogram

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: Phase III—no radiocarbon dates

text: Phase III—no radiocarbon dates

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: phase iii

answers: NDQ_005713

answers: no radiocarbon dates

answers: NDQ_005714

answers: phase iii

answers: NDQ_005715

answers: no radiocarbon dates

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: Phase III does not use radiocarbon

answers: NDQ_005718

answers: no radiocarbon dates

answers: NDQ_005719

answers: no radiocarbon

answers: NDQ_005720

answers: no radiocarbon dates

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Phase III—no

answers: NDQ_005713

answers: Phase III—no

answers: NDQ_005714

answers: Phase III—no

answers: NDQ_005715

answers: Phase III—no radiocarbon dates

answers: NDQ_005716

answers: Phase III—no radiocarbon dates

answers: NDQ_005717

answers: Phase III—no

answers: NDQ_005718

answers: III—no radiocarbon dates

answers: NDQ_005719

answers: Phase III—no

answers: NDQ_005720

answers: Phase III—no

text: The measures were again implemented on December 31, 2012 being the start of the debt ceiling crisis of 2013 with the default trigger date ticking to February 2013. The crisis was deferred with the suspension of the limit on February 4, and the cancellation of the extraordinary measures. The measures were again invoked at the end of the ceiling's suspension on May 19, 2013 with the date of exhaustion of the resources and the default trigger date being estimated by Treasury as October 17.  The ceiling was again suspended by legislation on that date until February 4, 2014.

text: The measures were again implemented on December 31, 2012 being the start of the

entity_name: United States debt-ceiling crisis of 2013

text: debt ceiling crisis of 2013

text: with the default trigger date ticking to February 2013. The crisis was deferred with the suspension of the limit on February 4, and the cancellation of the extraordinary measures. The measures were again invoked at the end of the ceiling's suspension on May 19, 2013 with the date of exhaustion of the resources and the default trigger date being estimated by Treasury as October 17.  The ceiling was again suspended by legislation on that date until February 4, 2014.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: date of exhaustion of the resources

answers: NDQ_005718

answers: date of exhaustion

answers: NDQ_005719

answers: The measures were again implemented on December 31, 2012 being the start of the debt ceiling crisis of 2013 with the default trigger date ticking to February 2014.

answers: NDQ_005720

answers: NDQ_005711

answers: October 17.

answers: NDQ_005712

answers: 2012

answers: NDQ_005713

answers: December 31, 2012

answers: NDQ_005714

answers: 2012

answers: NDQ_005715

answers: 2012

answers: NDQ_005716

answers: date of exhaustion of the resources

answers: NDQ_005717

answers: October 17.

answers: NDQ_005718

answers: date of exhaustion of the resources

answers: NDQ_005719

answers: 2012

answers: NDQ_005720

answers: 2012

text: The oldest rocks at Irruputuncu are lavas that have been dated by potassium-argon dating to 10.8 ± 0.6 mya. The oldest component clearly belonging to the volcano is the El Pozo ignimbrite that was erupted 258.2 ± 48.8 ka, forming a multi-layered ignimbrite that was probably generated by the injection of new, hot magma into older, cooler magma. A lava dome on the upper flank on the western side of the volcano is 0.14 ± 0.04 mya old. The block-and-ash flow between 55.9 ka and 140 ka old, but has not been pecisely dated. The Crater lavas are 55.9 ± 26.8 ka old. The block-and-ash flow on the southwestern flank was formed 1570 ± 900 years BP.

text: The oldest rocks at Irruputuncu are lavas that have been dated by

text: potassium-argon dating

text: to 10.8 ± 0.6 mya. The oldest component clearly belonging to the volcano is the El Pozo ignimbrite that was erupted 258.2 ± 48.8 ka, forming a multi-layered ignimbrite that was probably generated by the injection of new, hot magma into older, cooler magma. A lava dome on the upper flank on the western side of the volcano is 0.14 ± 0.04 mya old. The block-and-ash flow between 55.9 ka and 140 ka old, but has not been pecisely dated. The Crater lavas are 55.9 ± 26.8 ka old. The block-and-ash flow on the southwestern flank was formed 1570 ± 900 years BP.

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: What is potassium-argon dating?

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: How long does it take for carbon-14 to decay to carbon-12?

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: 10.8  0.6 mya

answers: NDQ_005718

answers: not been pecisely dated

answers: NDQ_005719

answers: It's impossible to say

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon dating to 10.8 <unk> 0.6 mya.

answers: NDQ_005713

answers: potassium-argon dating to 10.8 <unk> 0.6 mya.

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 10.8 <unk> 0.6 mya.

answers: NDQ_005718

answers: has not been pecisely dated.

answers: NDQ_005719

answers: potassium-argon dating to 10.8 <unk> 0.6 mya.

answers: NDQ_005720

answers: potassium-argon

text: The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained. Research has been ongoing since the 1960s to determine what the proportion of  in the atmosphere has been over the past fifty thousand years. The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age. Other corrections must be made to account for the proportion of  in different types of organisms (fractionation), and the varying levels of  throughout the biosphere (reservoir effects).  Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s. Because the time it takes to convert biological materials to fossil fuels is substantially longer than the time it takes for its  to decay below detectable levels, they contain almost no , and as a result there was a noticeable drop in the proportion of  in the atmosphere beginning in the late 19th century. Conversely, nuclear testing increased the amount of  in the atmosphere, which attained a maximum in 1963 of almost twice what it had been before the testing began.

text: The idea behind radiocarbon dating is straightforward, but years of work were required to develop the technique to the point where accurate dates could be obtained. Research has been ongoing since the 1960s to determine what the proportion of  in the atmosphere has been over the past fifty thousand years. The resulting data, in the form of a calibration curve, is now used to convert a given measurement of radiocarbon in a sample into an estimate of the sample's calendar age. Other corrections must be made to account for the proportion of  in different types of organisms (fractionation), and the varying levels of  throughout the

text: biosphere

text: (reservoir effects).  Additional complications come from the burning of fossil fuels such as coal and oil, and from the above-ground nuclear tests done in the 1950s and 1960s. Because the time it takes to convert biological materials to

text: fossil fuels

text: is substantially longer than the time it takes for its  to decay below detectable levels, they contain almost no , and as a result there was a noticeable drop in the proportion of  in the atmosphere beginning in the late 19th century. Conversely, nuclear testing increased the amount of  in the atmosphere, which attained a maximum in 1963 of almost twice what it had been before the testing began.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is a non-radioactive element

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radiocarbon in a sample

answers: NDQ_005718

answers: the burning of fossil fuels

answers: NDQ_005719

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: calendar age.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: estimate of the sample's calendar age.

answers: NDQ_005715

answers: fifty thousand years.

answers: NDQ_005716

answers: decay below detectable levels,

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: burning of fossil fuels

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: Despite the large shift, the change in direction was never recorded by magnetic declinations, fracture zone orientations or plate reconstructions; nor could a continental collision have occurred fast enough to produce such a pronounced bend in the chain. To test whether or not the bend was a result of a change in direction of the Pacific Plate, scientists analyzed the lava samples' geochemistry to determine where and when they formed. Age was determined by the radiometric dating of radioactive isotopes of potassium and argon. Researchers estimated that the volcanoes formed during a period 81 million to 45 million years ago. Tarduno and his team determined where the volcanoes formed by analyzing the rock for the magnetic mineral magnetite. While hot lava from a volcanic eruption cools, tiny grains within the magnetite align with the Earth's magnetic field, and lock in place once the rock solidifies. Researchers were able to verify the latitudes at which the volcanoes formed by measuring the grains' orientation within the magnetite. Paleomagnetists concluded that the Hawaiian hotspot had drifted southward sometime in its history, and that, 47 million years ago, the hotspot's southward motion greatly slowed, perhaps even stopping entirely.

text: Despite the large shift, the change in direction was never recorded by

text: magnetic declination

text: s,

text: fracture zone

text: orientations or

text: plate reconstruction

text: s; nor could a

text: continental collision

text: have occurred fast enough to produce such a pronounced bend in the chain. To test whether or not the bend was a result of a change in direction of the Pacific Plate, scientists analyzed the lava samples' geochemistry to determine where and when they formed. Age was determined by the

text: radiometric dating

text: of radioactive isotopes of

text: potassium

text: and

text: argon

text: . Researchers estimated that the volcanoes formed during a period 81 million to 45 million years ago. Tarduno and his team determined where the volcanoes formed by analyzing the rock for the magnetic mineral

text: magnetite

text: . While hot lava from a volcanic eruption cools, tiny grains within the magnetite align with the

text: Earth's magnetic field

text: , and lock in place once the rock solidifies. Researchers were able to verify the latitudes at which the volcanoes formed by measuring the grains' orientation within the magnetite.

text: Paleomagnetist

text: s concluded that the Hawaiian hotspot had drifted southward sometime in its history, and that, 47 million years ago, the hotspot's southward motion greatly slowed, perhaps even stopping entirely.

answers: NDQ_005711

answers: radioactive isotopes

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radioactive isotopes

answers: NDQ_005715

answers: radioactive isotopes of potassium and argon

answers: NDQ_005716

answers: the rock solidify

answers: NDQ_005717

answers: radioactive isotopes of potassium and argon

answers: NDQ_005718

answers: change in direction

answers: NDQ_005719

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: radioactive isotopes of potassium and argon.

answers: NDQ_005712

answers: radioactive isotopes of potassium and argon.

answers: NDQ_005713

answers: radioactive isotopes of potassium and argon.

answers: NDQ_005714

answers: radiometric dating of radioactive isotopes

answers: NDQ_005715

answers: 81 million to 45 million years ago.

answers: NDQ_005716

answers: Age was determined by the radiometric dating

answers: NDQ_005717

answers: radioactive isotopes

answers: NDQ_005718

answers: the change in direction was never recorded by magnetic declinations,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radioactive isotopes of potassium and argon.

text: Among the best power conversions achieved to date using CNTs were obtained by depositing a SWCNT layer between the ITO and the PEDOT : PSS or between the PEDOT : PSS and the photoactive blend in a modified ITO/PEDOT : PSS/ P3HT : (6,6)-phenyl-C-butyric acid methyl ester (PCBM)/Al solar cell. By dip-coating from a hydrophilic suspension, SWCNT were deposited after an initially exposing the surface to an argon plasma to achieve a power conversion efficiency of 4.9%, compared to 4% without CNTs.

text: Among the best power conversions achieved to date using CNTs were obtained by depositing a SWCNT layer between the ITO and the PEDOT : PSS or between the PEDOT : PSS and the photoactive blend in a modified ITO/PEDOT : PSS/ P3HT : (6,6)-phenyl-C-butyric acid methyl ester (PCBM)/Al solar cell. By dip-coating from a

text: hydrophilic

text: suspension, SWCNT were deposited after an initially exposing the surface to an argon plasma to achieve a power conversion efficiency of 4.9%, compared to 4% without CNTs.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: CNTs

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: SWCNT were deposited after an initially exposing the surface to an argon plasma

answers: NDQ_005718

answers: power conversion efficiency

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: argon plasma

answers: NDQ_005712

answers: CNTs

answers: NDQ_005713

answers: 4%

answers: NDQ_005714

answers: 4%

answers: NDQ_005715

answers: 4%

answers: NDQ_005716

answers: CNTs

answers: NDQ_005717

answers: 4.9%,

answers: NDQ_005718

answers: 4%

answers: NDQ_005719

answers: argon plasma to achieve a power conversion efficiency of 4.9%,

answers: NDQ_005720

answers: 4%

text: The rubidium-strontium dating method is a radiometric dating technique used by scientists to determine the age of rocks and minerals from the quantities they contain of specific isotopes of rubidium (Rb) and strontium (Sr, Sr).

text: The rubidium-strontium dating method is a

text: radiometric dating

text: technique used by

text: scientist

text: s to determine the

text: age

text: of rocks and minerals from the quantities they contain of specific isotopes of rubidium (Rb) and strontium (Sr, Sr).

answers: NDQ_005711

answers: radioactive isotopes

answers: NDQ_005712

answers: rubidium-strontium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: rubidium-strontium

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: isotopes of argon

answers: NDQ_005718

answers: age of rocks and minerals

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: from the quantities they contain of specific isotopes

answers: NDQ_005712

answers: quantities they contain of specific isotopes

answers: NDQ_005713

answers: The rubidium-strontium dating method

answers: NDQ_005714

answers: specific isotopes

answers: NDQ_005715

answers: The rubidium-strontium dating method

answers: NDQ_005716

answers: quantities they contain of specific isotopes

answers: NDQ_005717

answers: specific isotopes

answers: NDQ_005718

answers: quantities they contain of specific isotopes

answers: NDQ_005719

answers: The rubidium-strontium

answers: NDQ_005720

answers: The rubidium-strontium dating method

text: While she was a graduate student at Harvard in 1969, Behrensmeyer was invited by paleoanthropologist Richard Leakey to be his team's geologist and map fossil deposits at Koobi Fora in Kenya. She discovered a cluster of stone tools eroding out of a volcanic tuff, an ash layer from an ancient eruption that filled a small paleochannel. The site was named in her honor and the layer was named the Kay Behrensmeyer Site Tuff or KBS Tuff. The tools were similar to those discovered by Mary Leakey at Olduvai Gorge. The team's radiometric dating indicated that the fossils were 2.6 million years old. The dating of the site was controversial, as it contradicted other paleobiological evidence. A later independent investigation revised the date to 1.9 mya.

text: While she was a graduate student at Harvard in 1969, Behrensmeyer was invited by paleoanthropologist

text: Richard Leakey

text: to be his team's geologist and map fossil deposits at

text: Koobi Fora

text: in Kenya. She discovered a cluster of

text: stone tools

text: eroding out of a volcanic

text: tuff

text: , an ash layer from an ancient eruption that filled a small paleochannel. The site was named in her honor and the layer was named the Kay Behrensmeyer Site Tuff or KBS Tuff. The tools were similar to those discovered by

text: Mary Leakey

text: at

text: Olduvai Gorge

text: . The team's

text: radiometric dating

text: indicated that the fossils were 2.6 million years old. The dating of the site was controversial, as it contradicted other paleobiological evidence. A later independent investigation revised the date to 1.9 mya.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: 2.6 million years old

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: How long does carbon-14 decay?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 1.9 mya

answers: NDQ_005718

answers: contradicted other paleobiological evidence

answers: NDQ_005719

answers: radiometric dating indicated that the fossils were

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 2.6 million years old.

answers: NDQ_005712

answers: 2.6 million years old.

answers: NDQ_005713

answers: 2.6 million years old.

answers: NDQ_005714

answers: radiometric dating indicated that the fossils were 2.6 million years old.

answers: NDQ_005715

answers: 2.6

answers: NDQ_005716

answers: radiometric dating indicated that the fossils were 2.6 million years old.

answers: NDQ_005717

answers: 2.6 million years old.

answers: NDQ_005718

answers: it contradicted other paleobiological evidence.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: 1.9 mya.

text: From 1835 to 1977, it was wrongly believed that Harald ordered the death of the Haraldskær Woman, a bog body previously thought to be Gunnhild, Mother of Kings until radiocarbon dating proved otherwise.

text: From 1835 to 1977, it was wrongly believed that Harald ordered the death of the

text: Haraldskær Woman

text: , a

text: bog body

text: previously thought to be

text: Gunnhild, Mother of Kings

text: until

text: radiocarbon dating

text: proved otherwise.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating proved otherwise

answers: NDQ_005718

answers: radiocarbon dating is not reliable

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating

text: Afromyrma is known from a solitary fossil from Orapa, the holotype, specimen number BP/2/26501 tentatively identified as a female, though there is a possibility this is incorrect.  The holotype specimen is mostly complete but is rather poor in details, and is preserved as a compression fossil in shale.  The shales and mudstones of the Orapa site were rapidly deposited in a crater lake formed as the result of a large volcanic eruption in the Cretaceous.  The sediment originated as an epiclastic kimberlite and derives from rapid weathering and decomposition of the sides of the kimberlite crater.  Of the four major sedimentation types that have been observe at Orapa, fossils are found in only two, the granular mass flows and the fine-grained sediments:  woody debris fossils are found in the granular mass flows, but well-preserved fossils are only recovered in the fine-grained sediments.  The fossil-bearing stratum was uncovered during mining of the underlying diamond-bearing rocks at the site.  radiometric dating of the kimberlite pipe reported on in 1977 gave a general age between .  Further dating utilizing zircon crystals reported on in 2004 gave more defined age of approximately  placing the date in the Turonian age of the late Cretaceous.

text: Afromyrma is known from a solitary fossil from Orapa, the

text: holotype

text: , specimen number BP/2/26501 tentatively identified as a female, though there is a possibility this is incorrect.  The holotype specimen is mostly complete but is rather poor in details, and is preserved as a compression fossil in shale.  The shales and mudstones of the Orapa site were rapidly deposited in a

text: crater lake

text: formed as the result of a large volcanic eruption in the Cretaceous.  The sediment originated as an epiclastic

text: kimberlite

text: and derives from rapid weathering and decomposition of the sides of the kimberlite crater.  Of the four major sedimentation types that have been observe at Orapa, fossils are found in only two, the granular mass flows and the fine-grained sediments:  woody debris fossils are found in the granular mass flows, but well-preserved fossils are only recovered in the fine-grained sediments.  The fossil-bearing stratum was uncovered during mining of the underlying

text: diamond-bearing rocks at the site

text: radiometric dating

text: of the kimberlite pipe reported on in 1977 gave a general age between .  Further dating utilizing zircon crystals reported on in 2004 gave more defined age of approximately  placing the date in the

text: Turonian age

text: of the late Cretaceous.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: zircon crystals

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: zircon crystals

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: a general age between

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: rapid weathering and decomposition

answers: NDQ_005712

answers: Turonian age of the late Cretaceous.

answers: NDQ_005713

answers: Turonian age of the late Cretaceous.

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: Turonian age of the late Cretaceous.

answers: NDQ_005716

answers: decomposition

answers: NDQ_005717

answers: zircon crystals

answers: NDQ_005718

answers: poor in details,

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: Turonian age of the late Cretaceous.

text: Potassium-argon dating indicates  that the volcano last erupted about 120,000 years ago in the late Pleistocene.  Kohala is currently in transition between the postshield and erosional Hawaiian volcanic stages in the life cycle of Hawaiian volcanoes.

text: Potassium-argon dating

text: indicates  that the volcano last erupted about 120,000 years ago in the late

text: Pleistocene

text: .  Kohala is currently in transition between the

text: postshield

text: and

text: erosional

text: Hawaiian volcanic stages

text: in the life cycle of Hawaiian volcanoes.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: indicates that the volcano last erupted about 120,000 years ago

answers: NDQ_005718

answers: non-relative accuracy

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: Potassium-argon

answers: NDQ_005713

answers: Potassium-argon

answers: NDQ_005714

answers: Potassium-argon

answers: NDQ_005715

answers: 120,000 years ago in the late Pleistocene.

answers: NDQ_005716

answers: Potassium-argon

answers: NDQ_005717

answers: the volcano last erupted about 120,000 years ago

answers: NDQ_005718

answers: Potassium-argon

answers: NDQ_005719

answers: 120,000 years ago in the late Pleistocene.

answers: NDQ_005720

answers: Potassium-argon

text: The date Alexios entered Trebizond may be narrowed down even further. Sergey Karpov has identified a lead seal of Alexios, on one side "the image of a strategos in the peaked helmet leaded by hand by St. George" with the inscriptions Ἀλέξιος ὁ Κομνηνός [Alexios Komnenos] and Ὁ Ἅ(γιος) Γεώργιος [Saint George] on either side; on the obverse is a scene of Ἡ Ἁγία Ἀνάστασις [The Holy Resurrection] with the corresponding inscription. Karpov interprets the significance of this image and the inscription as portraying the most important achievement of his life, St. George inviting the victorious prince to enter Trebizond and opening the gates of the city with his left hand. The importance of St. George was that Easter—the date of the Resurrection—in 1204 fell on 25 April, while the memorial date of St. George was 23 April. "So I dared to assume," writes Karpov, "that the seal points out the date of the capture of Trebizond."

text: The date Alexios entered Trebizond may be narrowed down even further.

text: Sergey Karpov

text: has identified a lead seal of Alexios, on one side "the image of a

text: strategos

text: in the peaked helmet leaded by hand by St. George" with the inscriptions Ἀλέξιος ὁ Κομνηνός [Alexios Komnenos] and Ὁ Ἅ(γιος) Γεώργιος [Saint George] on either side; on the obverse is a scene of Ἡ Ἁγία Ἀνάστασις [The Holy Resurrection] with the corresponding inscription. Karpov interprets the significance of this image and the inscription as portraying the most important achievement of his life, St. George inviting the victorious prince to enter Trebizond and opening the gates of the city with his left hand. The importance of St. George was that Easter—the date of the Resurrection—in 1204 fell on 25 April, while the memorial date of St. George was 23 April. "So I dared to assume," writes Karpov, "that the seal points out the date of the capture of Trebizond."

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: date of the Resurrection—in 1204

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: lead seal

answers: NDQ_005712

answers: 1204

answers: NDQ_005713

answers: St. George"

answers: NDQ_005714

answers: Easter—the date of the Resurrection—in 1204

answers: NDQ_005715

answers: Easter—the date of the Resurrection—in 1204

answers: NDQ_005716

answers: Resurrection—in

answers: NDQ_005717

answers: 1204

answers: NDQ_005718

answers: narrowed down

answers: NDQ_005719

answers: lead seal

answers: NDQ_005720

answers: lead seal of Alexios,

text: Nevado San Francisco, or Cerro San Francisco (), is a stratovolcano on the border between Argentina and Chile, located just southeast of San Francisco Pass. It is considered extinct and is one of the several  peaks in the area, of which the chief is the Ojos del Salado. The volcano is composed from andesite with the exception of basaltic cones and lava flows on the eastern side. These cones are part of the Peinado lineament and a sample was dated 200,000 years ago by argon chronology. On the summit lie two circle-shaped constructs, of Inca or Formative period ages.

text: Nevado San Francisco, or Cerro San Francisco (), is a

text: stratovolcano

text: on the border between

text: Argentina

text: and

text: Chile

text: , located just southeast of

text: San Francisco Pass

text: . It is considered extinct and is one of the several  peaks in the area, of which the chief is the

text: Ojos del Salado

text: . The volcano is composed from

text: andesite

text: with the exception of basaltic cones and lava flows on the eastern side. These cones are part of the Peinado lineament and a sample was dated 200,000 years ago by argon chronology. On the summit lie two circle-shaped constructs, of Inca or Formative period ages.

answers: NDQ_005711

answers: argon

answers: NDQ_005712

answers: argon

answers: NDQ_005713

answers: What is radiometric dating?

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: It is considered extinct

answers: NDQ_005717

answers: 200,000 years ago

answers: NDQ_005718

answers: argon chronology

answers: NDQ_005719

answers: How old is the sample?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: argon chronology.

answers: NDQ_005712

answers: Inca or Formative period

answers: NDQ_005713

answers: 200,000 years ago by argon chronology.

answers: NDQ_005714

answers: 200,000 years ago by argon chronology.

answers: NDQ_005715

answers: 200,000 years ago by argon chronology.

answers: NDQ_005716

answers: argon chronology.

answers: NDQ_005717

answers: 200,000 years ago

answers: NDQ_005718

answers: argon chronology.

answers: NDQ_005719

answers: 200,000 years ago by argon chronology.

answers: NDQ_005720

answers: 200,000 years ago by argon chronology.

text: The abundances of the noble gases in the universe decrease as their atomic numbers increase. Helium is the most common element in the universe after hydrogen, with a mass fraction of about 24%. Most of the helium in the universe was formed during Big Bang nucleosynthesis, but the amount of helium is steadily increasing due to the fusion of hydrogen in stellar nucleosynthesis (and, to a very slight degree, the alpha decay of heavy elements). Abundances on Earth follow different trends; for example, helium is only the third most abundant noble gas in the atmosphere. The reason is that there is no primordial helium in the atmosphere; due to the small mass of the atom, helium cannot be retained by the Earth's gravitational field. Helium on Earth comes from the alpha decay of heavy elements such as uranium and thorium found in the Earth's crust, and tends to accumulate in natural gas deposits. The abundance of argon, on the other hand, is increased as a result of the beta decay of potassium-40, also found in the Earth's crust, to form argon-40, which is the most abundant isotope of argon on Earth despite being relatively rare in the Solar System. This process is the basis for the potassium-argon dating method. Xenon has an unexpectedly low abundance in the atmosphere, in what has been called the missing xenon problem; one theory is that the missing xenon may be trapped in minerals inside the Earth's crust. After the discovery of xenon dioxide, a research showed that Xe can substitute for Si in the quartz. Radon is formed in the lithosphere as from the alpha decay of radium. It can seep into buildings through cracks in their foundation and accumulate in areas that are not well ventilated. Due to its high radioactivity, radon presents a significant health hazard; it is implicated in an estimated 21,000 lung cancer deaths per year in the United States alone.

text: The abundances of the noble gases in the universe decrease as their

text: atomic number

text: s increase. Helium is the most common element in the

text: universe

text: after hydrogen, with a mass fraction of about 24%. Most of the helium in the universe was formed during

text: Big Bang nucleosynthesis

text: , but the amount of helium is steadily increasing due to the fusion of hydrogen in

text: stellar nucleosynthesis

text: (and, to a very slight degree, the

text: alpha decay

text: of heavy elements). Abundances on Earth follow different trends; for example, helium is only the third most abundant noble gas in the atmosphere. The reason is that there is no

text: primordial

text: helium in the atmosphere; due to the small mass of the atom, helium cannot be retained by the Earth's

text: gravitational field

text: . Helium on Earth comes from the

text: alpha decay

text: of heavy elements such as

text: uranium

text: and

text: thorium

text: found in the Earth's

text: crust

text: , and tends to accumulate in

text: natural gas deposit

text: s. The abundance of argon, on the other hand, is increased as a result of the

text: beta decay

text: of

text: , also found in the Earth's crust, to form

text: , which is the most abundant isotope of argon on Earth despite being relatively rare in the

text: Solar System

text: . This process is the basis for the

text: potassium-argon dating

text: method. Xenon has an unexpectedly low abundance in the atmosphere, in what has been called the missing xenon problem; one theory is that the missing xenon may be trapped in minerals inside the Earth's crust. After the discovery of

text: xenon dioxide

text: , a research showed that Xe can substitute for Si in the

text: quartz

text: . Radon is formed in the

text: lithosphere

text: as from the

text: alpha decay

text: of radium. It can seep into buildings through cracks in their foundation and accumulate in areas that are not well ventilated. Due to its high radioactivity, radon presents a significant health hazard; it is implicated in an estimated 21,000

text: lung cancer

text: deaths per year in the United States alone.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: potassium-argon dating method

answers: NDQ_005717

answers: This process is the basis for the potassium-argon dating method

answers: NDQ_005718

answers: radon presents a significant health hazard

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: potassium-argon dating method.

answers: NDQ_005712

answers: potassium-argon dating method.

answers: NDQ_005713

answers: potassium-argon dating method.

answers: NDQ_005714

answers: argon-40,

answers: NDQ_005715

answers: xenon dioxide,

answers: NDQ_005716

answers: argon-40,

answers: NDQ_005717

answers: argon-40,

answers: NDQ_005718

answers: Xenon has an unexpectedly low abundance in the atmosphere,

answers: NDQ_005719

answers: potassium-argon dating

answers: NDQ_005720

answers: potassium-argon dating method.

text: The decay series of U, which is called the actinium series, has 15 members and eventually decays into lead-207. The constant rates of decay in these decay series makes the comparison of the ratios of parent to daughter elements useful in radiometric dating.

text: The

text: decay series of U

text: , which is called the

text: actinium series

text: , has 15 members and eventually decays into lead-207. The constant rates of decay in these decay series makes the comparison of the ratios of parent to daughter elements useful in

text: radiometric dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: lead-207

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: lead-207 decays into lead

answers: NDQ_005715

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: comparison of the ratios of parent to daughter elements

answers: NDQ_005718

answers: constant rates of decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: comparison of the ratios of parent to daughter elements

answers: NDQ_005712

answers: constant rates of decay

answers: NDQ_005713

answers: comparison of the ratios of parent to daughter elements useful in radiometric dating.

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: lead-207.

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: comparison of the ratios of parent to daughter elements useful in radiometric dating.

answers: NDQ_005718

answers: constant rates of decay

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: Radiocarbon dates and Clovis points from farther south on the peninsula suggest that the initial occupation to the north must have occurred prior to 11,000 years ago.

text: Radiocarbon dates and

text: Clovis point

text: s from farther south on the peninsula suggest that the initial occupation to the north must have occurred prior to 11,000 years ago.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: Radiocarbon

answers: NDQ_005715

answers: Radiocarbon

answers: NDQ_005716

answers: Radiocarbon dates

answers: NDQ_005717

answers: the initial occupation to the north must have occurred prior to 11,000 years ago.

answers: NDQ_005718

answers: the initial occupation to the north must have occurred prior to 11,000 years ago.

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: Radiocarbon dates

text: The Miami Circle  is located on the site of a known Tequesta village south of the mouth of the Miami River (probably the town of Tequesta). It consists of 24 large holes or basins, and many smaller holes, which have been cut into bedrock. Together these holes form a circle approximately 38 feet in diameter. Other arrangements of holes are apparent as well. The Circle was discovered during an archeological survey of a site being cleared for construction of a high-rise building. Charcoal samples collected in the circle have been radiocarbon-dated to approximately 100 CE, 1,900 years ago. Radiocarbon-dating of sea shells eaten at the site date back as far as 730 BCE, and suggest a permanent settlement was established here more than 2,700 years ago. The circle is on the south side of the Miami River. Recent archaeological work has found a larger Tequesta site on the north side of the river that likely existed concurrently with the Miami Circle.

text: The

text: Miami Circle

text: is located on the site of a known Tequesta village south of the mouth of the Miami River (probably the town of Tequesta). It consists of 24 large holes or basins, and many smaller holes, which have been cut into bedrock. Together these holes form a circle approximately 38 feet in diameter. Other arrangements of holes are apparent as well. The Circle was discovered during an archeological survey of a site being cleared for construction of a high-rise building. Charcoal samples collected in the circle have been radiocarbon-dated to approximately 100 CE, 1,900 years ago. Radiocarbon-dating of sea shells eaten at the site date back as far as 730 BCE, and suggest a permanent settlement was established here more than 2,700 years ago. The circle is on the south side of the Miami River. Recent archaeological work has found a larger Tequesta site on the north side of the river that likely existed concurrently with the Miami Circle.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon-dating

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: Radiocarbon-dating

answers: NDQ_005717

answers: radiocarbon-dating

answers: NDQ_005718

answers: a permanent settlement was established here more than 2,700 years ago

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon-dated

answers: NDQ_005712

answers: radiocarbon-dated to approximately 100 CE, 1,900 years ago.

answers: NDQ_005713

answers: radiocarbon-dated to approximately 100 CE, 1,900 years ago.

answers: NDQ_005714

answers: 730 BCE,

answers: NDQ_005715

answers: 1,900 years ago.

answers: NDQ_005716

answers: radiocarbon-dated to approximately 100 CE, 1,900 years ago.

answers: NDQ_005717

answers: 730 BCE,

answers: NDQ_005718

answers: 1,900 years ago.

answers: NDQ_005719

answers: 730 BCE,

answers: NDQ_005720

answers: 730 BCE,

text: An olive tree in Algarve, Portugal, is 2000 years old, according to radiocarbon dating.

text: An olive tree in

text: Algarve

text: Portugal

text: , is 2000 years old, according to

text: radiocarbon dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: carbon is a nonrenewable resource

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: can be used to determine the age of minerals

answers: NDQ_005718

answers: radioactive isotopes

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 2000

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: An olive tree in Algarve, Portugal, is 2000 years old,

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: 2000 years old, according to radiocarbon dating.

text: ICP-MS is also used widely in the geochemistry field for radiometric dating, in which it is used to analyze relative abundance of different isotopes, in particular uranium and lead. ICP-MS is more suitable for this application than the previously used thermal ionization mass spectrometry, as species with high ionization energy such as osmium and tungsten can be easily ionized. For high precision ratio work, multiple collector instruments are normally used to reduce the effect noise on the calculated ratios.

text: ICP-MS is also used widely in the geochemistry field for radiometric dating, in which it is used to analyze relative abundance of different isotopes, in particular uranium and lead. ICP-MS is more suitable for this application than the previously used

text: thermal ionization mass spectrometry

text: , as species with high

text: ionization energy

text: such as

text: osmium

text: and

text: tungsten

text: can be easily ionized. For high precision ratio work, multiple collector instruments are normally used to reduce the effect noise on the calculated ratios.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: uranium and lead

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: ICP-MS is more suitable

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: ICP-MS is also used widely

answers: NDQ_005718

answers: effect noise on the calculated ratios

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: relative abundance of different isotopes,

answers: NDQ_005712

answers: relative abundance of different isotopes,

answers: NDQ_005713

answers: ICP-MS

answers: NDQ_005714

answers: species with high ionization energy

answers: NDQ_005715

answers: ICP-MS

answers: NDQ_005716

answers: radiometric dating,

answers: NDQ_005717

answers: ICP-MS

answers: NDQ_005718

answers: noise on the calculated ratios.

answers: NDQ_005719

answers: ICP-MS

answers: NDQ_005720

answers: radiometric dating,

text: Radiocarbon dates are generally presented with a range of one standard deviation (usually represented by the Greek letter sigma as 1σ) on either side of the mean. However, a date range of 1σ represents only 68% confidence level, so the true age of the object being measured may lie outside the range of dates quoted. This was demonstrated in 1970 by an experiment run by the British Museum radiocarbon laboratory, in which weekly measurements were taken on the same sample for six months. The results varied widely (though consistently with a normal distribution of errors in the measurements), and included multiple date ranges (of 1σ confidence) that did not overlap with each other. The measurements included one with a range from about 4250 to about 4390 years ago, and another with a range from about 4520 to about 4690.

text: Radiocarbon dates are generally presented with a range of one

text: standard deviation

text: (usually represented by the Greek letter sigma as 1σ) on either side of the mean. However, a date range of 1σ represents only 68% confidence level, so the true age of the object being measured may lie outside the range of dates quoted. This was demonstrated in 1970 by an experiment run by the British Museum radiocarbon laboratory, in which weekly measurements were taken on the same sample for six months. The results varied widely (though consistently with a

text: normal distribution

text: of errors in the measurements), and included multiple date ranges (of 1σ confidence) that did not overlap with each other. The measurements included one with a range from about 4250 to about 4390 years ago, and another with a range from about 4520 to about 4690.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: 4250 to about 4390

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: a date range of 1 represents only 68% confidence level

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: true age

answers: NDQ_005717

answers: Radiocarbon dates are generally presented with a range of one standard deviation

answers: NDQ_005718

answers: a date range of 1 represents only 68% confidence level

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: may lie outside the range of dates quoted.

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: a date range of 1<unk> represents only 68% confidence level,

answers: NDQ_005715

answers: Radiocarbon

answers: NDQ_005716

answers: the true age

answers: NDQ_005717

answers: Radiocarbon dates are generally presented with a range of one standard deviation

answers: NDQ_005718

answers: a date range of 1<unk> represents only 68% confidence level,

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: Radiocarbon dates

text: Recent radiocarbon dating indicates that populations survived as recently as 8,000 BC in western Siberia. However, the accuracy of this date is uncertain, as several radiocarbon plateaus exist around this time. The extinction does not coincide with the end of the last ice age, but does coincide with a minor yet severe climatic reversal that lasted for about 1,000–1,250 years, the Younger Dryas (GS1—Greenland Stadial 1), characterized by glacial readvances and severe cooling globally, a brief interlude in the continuing warming subsequent to the termination of the last major ice age (GS2), thought to have been due to a shutdown of the thermohaline circulation in the ocean due to huge influxes of cold fresh water from the preceding sustained glacial melting during the warmer Interstadial (GI1—Greenland Interstadial 1: ca. 16,000–11,450 C years B.P.).

text: Recent

text: radiocarbon dating

text: indicates that populations survived as recently as

text: 8,000 BC

text: in western

text: Siberia

text: . However, the accuracy of this date is uncertain, as several radiocarbon plateaus exist around this time. The extinction does not coincide with the end of the last ice age, but does coincide with a minor yet severe climatic reversal that lasted for about 1,000–1,250 years, the

text: Younger Dryas

text: (GS1—Greenland Stadial 1), characterized by glacial readvances and severe cooling globally, a brief interlude in the continuing warming subsequent to the termination of the last major ice age (GS2), thought to have been due to a shutdown of the

text: thermohaline circulation

text: in the ocean due to huge influxes of cold fresh water from the preceding sustained glacial melting during the warmer Interstadial (GI1—Greenland Interstadial 1: ca. 16,000–11,450 C years B.P.).

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: as recently as 8,000 BC in western Siberia

answers: NDQ_005718

answers: accuracy of this date is uncertain

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: the accuracy of this date is uncertain,

answers: NDQ_005715

answers: 8,000 BC

answers: NDQ_005716

answers: radiocarbon dating indicates that populations survived

answers: NDQ_005717

answers: 8,000 BC

answers: NDQ_005718

answers: accuracy of this date is uncertain,

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating

text: In the fall of 1960, M. Posnansky conducted further investigations at Bigo with the intent to "make as complete a survey as possible ... to establish the cultural sequence [of the site] and to obtain charcoal samples for Carbon 14 dating." During his investigation of Bigo, Posnansky spent over 7 weeks excavating more than 20 trenches (with a total volume of 781 cubic feet) at four locations (three within the main enclosure area and one at the outer ditch). From these trenches Posnansky prepared sidewall illustrations characterizing the site's soils and exposing the construction history of the mounds and ditches. Also recovered from the trenches were four charcoal samples that were submitted for radiometric dating and over 4,200 pottery sherds.

text: In the fall of 1960, M. Posnansky conducted further investigations at Bigo with the intent to "make as complete a survey as possible ... to establish the cultural sequence [of the site] and to obtain charcoal samples for

text: Carbon 14 dating

text: ." During his investigation of Bigo, Posnansky spent over 7 weeks excavating more than 20 trenches (with a total volume of 781 cubic feet) at four locations (three within the main enclosure area and one at the outer ditch). From these trenches Posnansky prepared sidewall illustrations characterizing the site's soils and exposing the construction history of the mounds and ditches. Also recovered from the trenches were four charcoal samples that were submitted for radiometric dating and over 4,200 pottery

text: sherd

text: s.

answers: NDQ_005711

answers: Carbon 14

answers: NDQ_005712

answers: Carbon 14 dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: Carbon 14 dating

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Carbon 14

answers: NDQ_005712

answers: Carbon 14

answers: NDQ_005713

answers: Carbon 14

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: Carbon 14

answers: NDQ_005716

answers: Carbon 14

answers: NDQ_005717

answers: Carbon 14

answers: NDQ_005718

answers: Carbon 14

answers: NDQ_005719

answers: Carbon 14

answers: NDQ_005720

answers: Carbon 14

text: Three of these isotopes are also found in three of the four major decay chains: lead-206, lead-207, and lead-208, are the final decay products of uranium-238, uranium-235, and thorium-232, respectively; the decay chains are called the uranium series, actinium series, and thorium series. Since the amounts of them in nature depend on the presence of other elements, the isotopic composition of natural lead varies between samples: in particular, the relative amount of lead-206 may vary between 20.84% and 27.78%, and the abundance of lead-208 may vary between 52.4% in normal samples to 90% in thorium ores. (For this reason, the atomic weight of lead is given to only one decimal place.) As time passes, the ratio of lead-206 and lead-207 to lead-204 increase, since the former two are supplemented by radioactive decay of heavier elements and the latter is not; this allows for lead–lead dating. Analogously, as uranium decays (eventually) into lead, their relative amounts change; this allows for uranium–lead dating.

text: Three of these isotopes are also found in three of the four major

text: decay chains

text: : lead-206, lead-207, and lead-208, are the final decay products of uranium-238, uranium-235, and thorium-232, respectively; the decay chains are called the uranium series, actinium series, and thorium series. Since the amounts of them in nature depend on the presence of other elements, the isotopic composition of natural lead varies between samples: in particular, the relative amount of lead-206 may vary between 20.84% and 27.78%, and the abundance of lead-208 may vary between 52.4% in normal samples to 90% in thorium ores. (For this reason, the atomic weight of lead is given to only one decimal place.) As time passes, the ratio of lead-206 and lead-207 to lead-204 increase, since the former two are supplemented by radioactive decay of heavier elements and the latter is not; this allows for

text: lead–lead dating

text: . Analogously, as uranium decays (eventually) into lead, their relative amounts change; this allows for

text: uranium–lead dating

answers: NDQ_005711

answers: lead–lead dating

answers: NDQ_005712

answers: lead–lead dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: lead–lead dating

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: lead–lead dating

answers: NDQ_005717

answers: lead-206 and lead-207 to lead-204 increase

answers: NDQ_005718

answers: natural lead varies between samples

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactive decay of heavier elements

answers: NDQ_005712

answers: radioactive decay of heavier elements

answers: NDQ_005713

answers: lead–lead dating.

answers: NDQ_005714

answers: lead–lead dating.

answers: NDQ_005715

answers: lead-206, lead-207, and lead-208,

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: the ratio of lead-206 and lead-207 to lead-204 increase,

answers: NDQ_005718

answers: the isotopic composition of natural lead varies between samples:

answers: NDQ_005719

answers: lead–lead dating.

answers: NDQ_005720

answers: uranium–lead dating.

text: The Avalon-type assemblage is defined at Mistaken Point in Canada, the oldest locality with a large quantity of Ediacaran fossils.The assemblage is easily dated because it contains many fine ash-beds, which are a good source of zircons used in the uranium-lead method of radiometric dating. These fine-grained ash beds also preserve exquisite detail. Constituents of this biota appear to survive through until the extinction of all Ediacarans at the base of the Cambrian.

text: The Avalon-type assemblage is defined at

entity_name: Mistaken Point, Newfoundland and Labrador

text: Mistaken Point

text: in Canada, the oldest locality with a large quantity of Ediacaran fossils.The assemblage is easily dated because it contains many fine ash-beds, which are a good source of

text: zircon

text: s used in the uranium-lead method of

text: radiometric dating

text: . These fine-grained ash beds also preserve exquisite detail. Constituents of this biota appear to survive through until the extinction of all Ediacarans at the base of the Cambrian.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: fine ash-beds

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-lead

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: zircons

answers: NDQ_005718

answers: uranium-lead method

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead

answers: NDQ_005712

answers: uranium-lead method

answers: NDQ_005713

answers: uranium-lead method

answers: NDQ_005714

answers: uranium-lead method of radiometric dating.

answers: NDQ_005715

answers: uranium-lead method of radiometric dating.

answers: NDQ_005716

answers: extinction

answers: NDQ_005717

answers: zircons

answers: NDQ_005718

answers: extinction

answers: NDQ_005719

answers: uranium-lead method of radiometric dating.

answers: NDQ_005720

answers: uranium-lead method of radiometric dating.

text: Fe and others are used for isochron dating of events in the early history of the solar system. However, methods using extinct radionuclides give only relative ages and have to be calibrated with radiometric dating techniques based on long living radionuclides like Pb-Pb-dating to give absolute ages.

text: Fe

text: and others are used for isochron dating of events in the early history of the

text: solar system

text: . However, methods using extinct radionuclides give only relative ages and have to be calibrated with radiometric dating techniques based on long living radionuclides like Pb-Pb-dating to give absolute ages.

answers: NDQ_005711

answers: yes

answers: NDQ_005712

answers: absolute ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: extinct radionuclides

answers: NDQ_005715

answers: NDQ_005716

answers: radionuclides

answers: NDQ_005717

answers: isochron dating

answers: NDQ_005718

answers: relative ages

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: long living radionuclides

answers: NDQ_005712

answers: long living radionuclides

answers: NDQ_005713

answers: long living radionuclides

answers: NDQ_005714

answers: relative ages

answers: NDQ_005715

answers: Pb-Pb-dating

answers: NDQ_005716

answers: relative ages

answers: NDQ_005717

answers: Pb-Pb-dating to give absolute ages.

answers: NDQ_005718

answers: relative ages

answers: NDQ_005719

answers: Pb-Pb-dating

answers: NDQ_005720

answers: Pb-Pb-dating

text: Bits of pottery discovered in a cave in the northwest coast of modern-day Kyushu date back to as far as 12,700 BCE in radiometric dating tests.

text: Bits of pottery discovered in a cave in the northwest coast of modern-day Kyushu date back to as far as 12,700 BCE in radiometric dating tests.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: radiometric dating only works for materials of this age

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating tests

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 12,700 BCE in radiometric dating tests.

answers: NDQ_005712

answers: 12,700 BCE

answers: NDQ_005713

answers: 12,700 BCE

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: 12,700 BCE

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 12,700 BCE

answers: NDQ_005718

answers: date back to as far as 12,700 BCE

answers: NDQ_005719

answers: radiometric dating tests.

answers: NDQ_005720

answers: radiometric dating tests.

text: Kulp's research in radiometric dating included:

text: Kulp's research in

text: radiometric dating

text: included:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: kulp is a scientist

answers: NDQ_005713

answers: radioactive isotopes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: Kulp's research included:

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: Kulp's research in radiometric dating

answers: NDQ_005712

answers: Kulp's research in radiometric dating

answers: NDQ_005713

answers: Kulp's

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: Kulp's research in radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Kulp's research in radiometric dating

answers: NDQ_005718

answers: radiometric dating

answers: NDQ_005719

answers: Kulp's research in radiometric dating

answers: NDQ_005720

answers: Kulp's research in radiometric dating

text: By using stratigraphic principles, rock units' ages can usually only be determined relative to each other. For example, knowing that Mesozoic rock strata making up the Cretaceous System lie on top of (and are therefore younger than) rocks of the Jurassic System reveals nothing about how long ago the Cretaceous or Jurassic Periods were. Other methods, such as radiometric dating, are needed to determine absolute ages in geologic time. Generally, this is only known for rocks on the Earth. Absolute ages are also known for selected rock units of the Moon based on samples returned to Earth.

text: By using stratigraphic principles,

text: rock units

text: ' ages can usually only be determined

text: relative to each other

text: . For example, knowing that Mesozoic rock

text: strata

text: making up the

text: Cretaceous

text: System

text: lie on top of (and are therefore younger than) rocks of the

text: Jurassic

text: System reveals nothing about how long ago the Cretaceous or Jurassic Periods were. Other methods, such as

text: radiometric dating

text: , are needed to determine

text: absolute ages

text: in geologic time. Generally, this is only known for rocks on the Earth. Absolute ages are also known for selected rock units of the Moon based on samples returned to Earth.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: rocks on the Earth

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: absolute ages in geologic time

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: are needed to determine absolute ages in geologic time

answers: NDQ_005718

answers: Generally, this only known for rocks on the Earth

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: NDQ_005711

answers: absolute ages in geologic time.

answers: NDQ_005712

answers: rocks on the Earth.

answers: NDQ_005713

answers: Generally, this is only known for rocks on the Earth.

answers: NDQ_005714

answers: radiometric dating, are needed to determine absolute ages

answers: NDQ_005715

answers: radiometric dating,

answers: NDQ_005716

answers: radiometric dating, are needed to determine absolute ages in geologic time.

answers: NDQ_005717

answers: radiometric dating, are needed to determine absolute ages

answers: NDQ_005718

answers: Generally, this is only known for rocks on the Earth.

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: radiometric dating,

text: Absolute dating methods, by using absolute referent criteria, mainly include the so-called radiometric dating methods. Some examples of both radiometric and non-radiometric absolute dating methods are the following:

text: Absolute dating

text: methods, by using absolute referent criteria, mainly include the so-called

text: radiometric dating

text: methods. Some examples of both radiometric and non-radiometric absolute dating methods are the following:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: carbon-14 decays

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: absolute referent criteria

answers: NDQ_005718

answers: absolute referent criteria

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: using absolute referent criteria,

answers: NDQ_005712

answers: absolute referent criteria,

answers: NDQ_005713

answers: Absolute dating methods, by using absolute referent criteria,

answers: NDQ_005714

answers: Absolute dating methods, by using absolute referent criteria,

answers: NDQ_005715

answers: radiometric dating methods.

answers: NDQ_005716

answers: radiometric

answers: NDQ_005717

answers: radiometric dating methods.

answers: NDQ_005718

answers: absolute referent criteria,

answers: NDQ_005719

answers: radiometric dating methods.

answers: NDQ_005720

answers: radiometric dating methods.

text: The consensus of professional scientific organisations worldwide is that no scientific evidence contradicts the age of approximately 4.5 billion years. Young Earth creationists reject these ages on the grounds of what they regard as being tenuous and untestable assumptions in the methodology. They have often quoted apparently inconsistent radiometric dates to cast doubt on the utility and accuracy of the method. Mainstream proponents who get involved in this debate point out that dating methods only rely on the assumptions that the physical laws governing radioactive decay have not been violated since the sample was formed (harking back to Lyell's doctrine of uniformitarianism). They also point out that the "problems" that creationists publicly mentioned can be shown to either not be problems at all, are issues with known contamination, or simply the result of incorrectly evaluating legitimate data. The fact that the various methods of dating give essentially identical or near identical readings is not addressed in creationism.

text: The consensus of professional scientific organisations worldwide is that no scientific evidence contradicts the age of approximately 4.5 billion years. Young Earth creationists reject these ages on the grounds of what they regard as being tenuous and untestable assumptions in the methodology. They have often quoted apparently inconsistent radiometric dates to cast doubt on the utility and accuracy of the method. Mainstream proponents who get involved in this debate point out that dating methods only rely on the assumptions that the

text: physical law

text: s governing

text: radioactive decay

text: have not been violated since the sample was formed (harking back to Lyell's doctrine of uniformitarianism). They also point out that the "problems" that creationists publicly mentioned can be shown to either not be problems at all, are issues with known contamination, or simply the result of incorrectly evaluating legitimate data. The fact that the various methods of dating give essentially identical or near identical readings is not addressed in creationism.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay have not been violated

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Lyell's doctrine of uniformitarianism

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: the physical laws governing radioactive decay have not been violated since the sample was formed

answers: NDQ_005718

answers: untestable assumptions

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: the physical laws governing radioactive decay

answers: NDQ_005713

answers: 4.5 billion years.

answers: NDQ_005714

answers: radioactive decay have not been violated since the sample was formed

answers: NDQ_005715

answers: 4.5 billion years.

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: radioactive decay have not been violated since the sample was formed

answers: NDQ_005718

answers: inconsistent

answers: NDQ_005719

answers: Young Earth creationists

answers: NDQ_005720

answers: 4.5 billion years.

text: Attempts have been made to date the figures using thermoluminescence (TL) dating. The earliest results, from tests done when TL dating was in its infancy, suggested a date around 2500 BC. However, later tests contradicted these findings. In 1976, Gary W. Carriveau and Mark C. Han attempted to date twenty Acámbaro figures using TL dating. They found that the figures had been fired at temperatures between 450 °C and 650 °C, which contradicted claims that these figures had been fired at temperatures too low for them to be accurately dated. However, all of the samples failed the "plateau test", which indicated that dates obtained for the Acámbaro figures using standard high-temperature TL dating techniques were unreliable and lacked any chronological significance. Based on the degree of signal regeneration found in remeasured samples, they estimated that the figures tested had been fired approximately 30 years prior to 1969.

text: Attempts have been made to date the figures using

text: thermoluminescence (TL) dating

text: . The earliest results, from tests done when TL dating was in its infancy, suggested a date around 2500 BC. However, later tests contradicted these findings. In 1976, Gary W. Carriveau and Mark C. Han attempted to date twenty Acámbaro figures using TL dating. They found that the figures had been fired at temperatures between 450 °C and 650 °C, which contradicted claims that these figures had been fired at temperatures too low for them to be accurately dated. However, all of the samples failed the "plateau test", which indicated that dates obtained for the Acámbaro figures using standard high-temperature TL dating techniques were unreliable and lacked any chronological significance. Based on the degree of signal regeneration found in remeasured samples, they estimated that the figures tested had been fired approximately 30 years prior to 1969.

answers: NDQ_005711

answers: thermoluminescence

answers: NDQ_005712

answers: thermoluminescence

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: thermoluminescence

answers: NDQ_005715

answers: NDQ_005716

answers: TL dating

answers: NDQ_005717

answers: Attempts have been made to date the figures using potassium-argon dating

answers: NDQ_005718

answers: unreliable

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: thermoluminescence

answers: NDQ_005712

answers: high-temperature

answers: NDQ_005713

answers: thermoluminescence

answers: NDQ_005714

answers: unreliable and lacked any chronological significance.

answers: NDQ_005715

answers: 2500 BC.

answers: NDQ_005716

answers: thermoluminescence

answers: NDQ_005717

answers: 450 °C and 650 °C,

answers: NDQ_005718

answers: lacked any chronological significance.

answers: NDQ_005719

answers: thermoluminescence

answers: NDQ_005720

answers: thermoluminescence

text: In cases where multiple radiocarbon dates have been determined from a single core, radiocarbon dates are typically consistent in terms of their stratigraphic position within a core and accumulation rates calculated from them only are rarely anomalous. Given the nature of radiocarbon dating, such discordant dates occasionally occur even in undisturbed deposits, when multiple samples were dated. The occasional discordant dates by themselves are meaningless as an indicator of disturbance. The intact internal stratigraphy of the bay sediments, as indicated by paleosols and pollen zones, e.g. Big Bay refutes such arguments.

text: In cases where multiple radiocarbon dates have been determined from a single core, radiocarbon dates are typically consistent in terms of their

text: stratigraphic

text: position within a core and accumulation rates calculated from them only are rarely anomalous. Given the nature of radiocarbon dating, such discordant dates occasionally occur even in undisturbed deposits, when multiple samples were dated. The occasional discordant dates by themselves are meaningless as an indicator of disturbance. The intact internal stratigraphy of the bay sediments, as indicated by paleosols and pollen zones, e.g. Big Bay refutes such arguments.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: discordant dates by themselves are meaningless as an indicator of disturbance

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dates are typically consistent in terms of their stratigraphic position within a core

answers: NDQ_005718

answers: discordant dates occasionally occur even in undisturbed deposits

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dates have been determined from a single core,

answers: NDQ_005713

answers: radiocarbon dating,

answers: NDQ_005714

answers: radiocarbon dates are typically consistent in terms of their stratigraphic position

answers: NDQ_005715

answers: radiocarbon dates

answers: NDQ_005716

answers: accumulation rates

answers: NDQ_005717

answers: discordant dates occasionally occur even in undisturbed deposits,

answers: NDQ_005718

answers: discordant dates occasionally occur even in undisturbed deposits,

answers: NDQ_005719

answers: In cases where multiple radiocarbon dates have been determined from a single core,

answers: NDQ_005720

answers: radiocarbon dates

text: The ship's single sail had probably been taken down before she sank as the stern contained more than 100 lead rigging rings from a large square sail stowed there. The wooden hull, built mostly of  pine (pinus brutia), was preserved for a length of almost 14,7 metres originally measured long,  by 4,4 metres across. The ship was built by using the "shell first" ancient method, rather the opposite of today's method. Contrary to the contemporary wood boat building method where a complete skeleton of frames of the entire vessel must first be constructed, in this case, the planking from the keel and up  was joined together using a mortice-and-tenon construction and then the frames were laid in,  secured with an ingenious assembly of  hollow cylindrical softwood inserts hosting internal copper nails passing through both frames and planks. The ship was intended for long service and underwent four major repairs in her life. In the last repair her owner(s) had a skin of lead sheathing of 1,5 to 2 millimeters thickness  applied to her body to hopefully keep the old ship comparatively safe from woodworm and probably help watertightness. Carbon 14 dating of the ship's planks gives a date of 389 BC (plus or minus 44 years). Carbon 14 dating of the almonds points to a date of 288 BC (plus or minus 62 years). Hence the ship was very old the day she sank.

answers: NDQ_005711

answers: Carbon 14

answers: NDQ_005712

answers: carbon 14 dating

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating measure when the organism died

answers: NDQ_005717

answers: carbon 14 dating

answers: NDQ_005718

answers: Hence the ship was very old the day she sank

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Carbon 14

answers: NDQ_005712

answers: Carbon 14

answers: NDQ_005713

answers: 288 BC (plus or minus 62 years).

answers: NDQ_005714

answers: 288 BC (plus or minus 62 years).

answers: NDQ_005715

answers: Carbon 14

answers: NDQ_005716

answers: Carbon 14 dating

answers: NDQ_005717

answers: 288 BC (plus or minus 62 years).

answers: NDQ_005718

answers: the ship was very old the day she sank.

answers: NDQ_005719

answers: Carbon 14

answers: NDQ_005720

answers: Carbon 14 dating

text: The earliest documentary evidence of a church on the site is dated 1246.  Nothing of this church remains but there is a crypt leading from the chancel which pre-dates the present church.  Most of the church was built in the early 16th century also, though it is possible that the lower part of the tower dates from the 15th century.  The Hawthorne Chapel was added to the south side of the church in 1700, replacing a former chantry dated 1520.  There was a restoration in 1862-63 by Brakspear, in 1878 J. S. Crowther added the vestry and the south porch, and a clerestory was added to the chancel in 1898 by Bodley and Garner.

text: The earliest documentary evidence of a church on the site is dated 1246.  Nothing of this church remains but there is a

text: crypt

text: leading from the

text: chancel

text: which pre-dates the present church.  Most of the church was built in the early 16th century also, though it is possible that the lower part of the tower dates from the 15th century.  The Hawthorne Chapel was added to the south side of the church in 1700, replacing a former

text: chantry

text: dated 1520.  There was a

text: restoration

text: in 1862-63 by Brakspear, in 1878

text: J. S. Crowther

text: added the

text: vestry

text: and the south porch, and a

text: clerestory

text: was added to the chancel in 1898 by

text: Bodley

text: and Garner.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: the lower part of the tower dates from the 15th century

answers: NDQ_005718

answers: nothing of this church remains

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: NDQ_005711

answers: documentary evidence of a church on the site is dated 1246.

answers: NDQ_005712

answers: early 16th century

answers: NDQ_005713

answers: 1246.

answers: NDQ_005714

answers: 1246.

answers: NDQ_005715

answers: 1700,

answers: NDQ_005716

answers: Nothing of this church remains

answers: NDQ_005717

answers: 1246.

answers: NDQ_005718

answers: Nothing of this church remains

answers: NDQ_005719

answers: 1246.

answers: NDQ_005720

answers: 1246.

text: However, subsequent studies cast doubt on this relatively recent age. In a 2006 study, Gao & Ren criticized He et al. for not including enough specifics and detail in their paper, and also took issue with their radiometric dating of the Daohugou tuff. The tuff, Gao and Ren argued, contains crystals with a variety of diverse radiometric ages, some up to a billion years old, so using dates from only a few of these crystals could not determine the overall age of the deposits. Gao and Ren went on to defend a Middle Jurassic age for the beds based on biostratigraphy (the use of index fossils), and the bed's relationship to a layer that is known to mark the Middle Jurassic-Late Jurassic boundary.

text: However, subsequent studies cast doubt on this relatively recent age. In a 2006 study, Gao & Ren criticized He et al. for not including enough specifics and detail in their paper, and also took issue with their radiometric dating of the Daohugou tuff. The tuff, Gao and Ren argued, contains crystals with a variety of diverse radiometric ages, some up to a billion years old, so using dates from only a few of these crystals could not determine the overall age of the deposits. Gao and Ren went on to defend a Middle Jurassic age for the beds based on

text: biostratigraphy

text: (the use of

text: index fossil

text: s), and the bed's relationship to a layer that is known to mark the Middle Jurassic-Late Jurassic boundary.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: use of index fossils

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: a billion years old

answers: NDQ_005715

answers: How long does the half-life of carbon-14 decay?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating of the Daohugou tuff

answers: NDQ_005718

answers: using dates from only a few of these crystals could not determine the overall age of the deposits

answers: NDQ_005719

answers: How old is the Daohugou tuff?

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: using dates from only a few of these crystals

answers: NDQ_005712

answers: diverse radiometric ages, some up to a billion years old,

answers: NDQ_005713

answers: radiometric ages, some up to a billion years old,

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: Middle Jurassic

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: some up to a billion years old,

answers: NDQ_005718

answers: using dates from only a few of these crystals

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: The taxable amount of a gift is the fair market value of the property in excess of consideration received at the date of gift. The taxable amount of an estate is the gross fair market value of all rights considered property at the date of death (or an alternative valuation date) ("gross estate"), less liabilities of the decedent, costs of administration (including funeral expenses) and certain other deductions. State estate taxes are deductible, with limitations, in computing the federal taxable estate. Bequests to charities reduce the taxable estate.

text: The taxable amount of a gift is the fair market value of the property in excess of consideration received at the date of gift. The taxable amount of an estate is the gross fair market value of all rights considered property at the date of death (or an alternative valuation date) ("gross estate"), less liabilities of the decedent, costs of administration (including funeral expenses) and certain other deductions. State estate taxes are deductible, with limitations, in computing the federal taxable estate. Bequests to charities reduce the taxable estate.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The taxable amount of a gift

answers: NDQ_005718

answers: State estate taxes are deductible

answers: NDQ_005719

answers: are useful for very young materials

answers: NDQ_005720

answers: NDQ_005711

answers: fair market value

answers: NDQ_005712

answers: date of death

answers: NDQ_005713

answers: The taxable amount of an estate

answers: NDQ_005714

answers: gross fair market value of all rights considered property at the date of death

answers: NDQ_005715

answers: Bequests to charities reduce the taxable estate.

answers: NDQ_005716

answers: gross fair market value of all rights considered property at the date of death

answers: NDQ_005717

answers: Bequests to charities reduce the taxable estate.

answers: NDQ_005718

answers: State estate taxes

answers: NDQ_005719

answers: The taxable amount of a gift

answers: NDQ_005720

answers: gift.

text: The Nemegt Formation was deposited within the Late Cretaceous, although its exact age is unknown as it has never been dated radiometrically. According to different authors, the formation is late Campanian to early Maastrichtian, early Maastrichtian, or middle Maastrichtian in age. The sediments of the Nemegt Formation were deposited in a plain crossed by rivers. The climate was warm and subhumid with seasonal droughts, and the soils were relatively dry. Nevertheless, the Nemegt Formation was more humid than the underlying (and thus older) Barun Goyot and Djadochta Formations, which show a semiarid climate.

text: The Nemegt Formation was deposited within the

text: Late Cretaceous

text: , although its exact age is unknown as it has never been

text: dated radiometrically

text: . According to different authors, the formation is late

text: Campanian

text: to early

text: Maastrichtian

text: , early Maastrichtian, or middle Maastrichtian in age. The sediments of the Nemegt Formation were deposited in a plain crossed by rivers. The climate was warm and

text: subhumid

text: with seasonal droughts, and the soils were relatively dry. Nevertheless, the Nemegt Formation was more humid than the underlying (and thus older)

text: Barun Goyot

text: and

text: Djadochta Formation

text: s, which show a

text: semiarid

text: climate.

answers: NDQ_005711

answers: radiometrically

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: has never been dated radiometrically

answers: NDQ_005718

answers: exact age is unknown

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiometrically.

answers: NDQ_005712

answers: Late Cretaceous,

answers: NDQ_005713

answers: radiometrically.

answers: NDQ_005714

answers: radiometrically.

answers: NDQ_005715

answers: Late Cretaceous,

answers: NDQ_005716

answers: radiometrically.

answers: NDQ_005717

answers: it has never been dated radiometrically.

answers: NDQ_005718

answers: exact age is unknown

answers: NDQ_005719

answers: radiometrically.

answers: NDQ_005720

answers: radiometrically.

text: Radiometric dates for much of the Cambrian, obtained by analysis of radioactive elements contained within rocks, have only recently become available, and for only a few regions.

text: Radiometric

text: dates for much of the Cambrian, obtained by analysis of radioactive elements contained within rocks, have only recently become available, and for only a few regions.

answers: NDQ_005711

answers: radioactive elements

answers: NDQ_005712

answers: radioactive elements

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: radioactive elements

answers: NDQ_005718

answers: only recently become available

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: analysis of radioactive elements contained within rocks,

answers: NDQ_005712

answers: radioactive elements contained within rocks,

answers: NDQ_005713

answers: radioactive elements contained within rocks,

answers: NDQ_005714

answers: radioactive elements contained within rocks,

answers: NDQ_005715

answers: Radiometric dates for much of the Cambrian,

answers: NDQ_005716

answers: radioactive elements

answers: NDQ_005717

answers: radioactive elements contained within rocks,

answers: NDQ_005718

answers: have only recently become available, and for only a few regions.

answers: NDQ_005719

answers: Radiometric dates

answers: NDQ_005720

answers: Radiometric dates for much of the Cambrian,

text: Finally, ages can also be determined from the U–Pb system by analysis of Pb isotope ratios alone. This is termed the lead-lead dating method. Clair Cameron Patterson, an American geochemist who pioneered studies of uranium–lead radiometric dating methods, is famous for having used it to obtain one of the earliest accurate estimates of the age of the Earth.

text: Finally, ages can also be determined from the U–Pb system by analysis of Pb isotope ratios alone. This is termed the

text: lead-lead dating

text: method.

text: Clair Cameron Patterson

text: , an American geochemist who pioneered studies of uranium–lead radiometric dating methods, is famous for having used it to obtain one of the earliest accurate estimates of the

text: age of the Earth

answers: NDQ_005711

answers: unanswerable

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: Pb isotope ratios

answers: NDQ_005717

answers: lead-lead

answers: NDQ_005718

answers: lead-lead dating method

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: analysis of Pb isotope ratios alone.

answers: NDQ_005712

answers: uranium–lead

answers: NDQ_005713

answers: lead-lead dating method.

answers: NDQ_005714

answers: lead-lead dating method.

answers: NDQ_005715

answers: lead-lead dating method.

answers: NDQ_005716

answers: Pb isotope ratios

answers: NDQ_005717

answers: analysis of Pb isotope ratios

answers: NDQ_005718

answers: analysis of Pb isotope ratios alone.

answers: NDQ_005719

answers: lead-lead dating method.

answers: NDQ_005720

answers: uranium–lead radiometric dating methods,

text: The waters of Paralana geothermal springs, located at Wooltana, north of Arkaroola, issue from geological faults that date back one billion years. These waters are heated by rich veins of radioactive uranium ore in the faults. Carbon dioxide, nitrogen, radon and helium bubble forth continuously. Because the Paralana springs contain small amounts of uranium and radon, staying near the springs for a prolonged period constitutes a health hazard. Living on the floor of the springs is an extremophile algal mat that survives the warm temperatures of 62 °C and high radioactivity.

text: The waters of Paralana

text: geothermal springs

text: , located at

text: Wooltana

text: , north of Arkaroola, issue from

text: geological fault

text: s that date back one billion years. These waters are heated by rich

text: veins

text: of radioactive

text: uranium ore

text: in the faults. Carbon dioxide, nitrogen,

text: radon

text: and helium bubble forth continuously. Because the Paralana springs contain small amounts of uranium and radon, staying near the springs for a prolonged period constitutes a

text: health hazard

text: . Living on the floor of the springs is an

text: extremophile

text: algal mat that survives the warm temperatures of 62 °C and high radioactivity.

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: geological faults

answers: NDQ_005713

answers: radioactive uranium

answers: NDQ_005714

answers: radioactive uranium

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: algal mat survive

answers: NDQ_005717

answers: radioactive uranium

answers: NDQ_005718

answers: health hazard

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactive uranium ore

answers: NDQ_005712

answers: one billion years.

answers: NDQ_005713

answers: one billion years.

answers: NDQ_005714

answers: high radioactivity.

answers: NDQ_005715

answers: one billion years.

answers: NDQ_005716

answers: date back one billion years.

answers: NDQ_005717

answers: one billion years.

answers: NDQ_005718

answers: health hazard.

answers: NDQ_005719

answers: one billion years.

answers: NDQ_005720

answers: one billion years.

text: Potassium-argon (K-Ar) dating of the Miri summit has yielded an age of 200,000 years, and an older date (5,900,000 ± 2,800,000) has been obtained from the northwestern centre. Between the two are andesite dates of 5,630,000 ± 90,000 years and 2,390,000 ± 50,000 years. Although the last activity occurred during the Pleistocene (probably a large eruption), volcanism began earlier. The youngest date, obtained from K-Ar dating of pumice, is 90,000 ± 10,000 years. Koh-i-Sultan's Pleistocene activity is probably related to the formation of travertine deposits, which are mined.

text: Potassium-argon (K-Ar) dating of the Miri summit has yielded an age of 200,000 years, and an older date (5,900,000 ± 2,800,000) has been obtained from the northwestern centre. Between the two are andesite dates of 5,630,000 ± 90,000 years and 2,390,000 ± 50,000 years. Although the last activity occurred during the

text: Pleistocene

text: (probably a large eruption),

text: volcanism

text: began earlier. The youngest date, obtained from K-Ar dating of

text: pumice

text: , is 90,000 ± 10,000 years. Koh-i-Sultan's Pleistocene activity is probably related to the formation of

text: travertine

text: deposits, which are mined.

answers: NDQ_005711

answers: K-Ar

answers: NDQ_005712

answers: K-Ar

answers: NDQ_005713

answers: NDQ_005714

answers: K-Ar dating of pumice is 90,000  10,000 years

answers: NDQ_005715

answers: NDQ_005716

answers: K-Ar

answers: NDQ_005717

answers: age of 200,000 years

answers: NDQ_005718

answers: age of 200,000 years

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium-argon

answers: NDQ_005712

answers: 200,000 years,

answers: NDQ_005713

answers: Potassium-argon

answers: NDQ_005714

answers: 200,000 years,

answers: NDQ_005715

answers: 200,000 years,

answers: NDQ_005716

answers: age of 200,000 years,

answers: NDQ_005717

answers: 200,000 years,

answers: NDQ_005718

answers: mined.

answers: NDQ_005719

answers: pumice,

answers: NDQ_005720

answers: 200,000 years,

text: Paul S.C. Taçon received his MA in Anthropology from Trent University in 1984 and his PhD from the Australian National University in 1990. He was based at the Australian Museum in Sydney from 1991 to 2005, acting as a Principal Research Scientist in Anthropology from 1998 to 2005 and Head of the Museum's People and Place Research Centre from 1995 to 2003. In 2005, Paul S.C. Taçon joined Griffith University and has since led two ongoing research programs, "Picturing Change" and "Late Pleistocene Peopling of East Asia". He has pioneered the use of radiocarbon dating of beeswax rock art, and his research team was the first to use uranium-series direct dates for rock art in China. Currently, he is leading the use of innovative three-dimensional laser scanners to conserve vulnerable rock art sites.

text: Paul S.C. Taçon received his MA in

text: Anthropology

text: from

text: Trent University

text: in 1984 and his PhD from the

text: Australian National University

text: in 1990. He was based at the

text: Australian Museum

text: in Sydney from 1991 to 2005, acting as a Principal Research Scientist in Anthropology from 1998 to 2005 and Head of the Museum's People and Place Research Centre from 1995 to 2003. In 2005, Paul S.C. Taçon joined

text: Griffith University

text: and has since led two ongoing research programs, "Picturing Change" and "Late Pleistocene Peopling of East Asia". He has pioneered the use of

text: radiocarbon dating

text: of

text: beeswax

text: rock art, and his research team was the first to use

text: uranium

text: -series direct dates for rock art in China. Currently, he is leading the use of innovative three-dimensional laser scanners to conserve vulnerable rock art sites.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon-14 is a noble gas

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating of beeswax rock art

answers: NDQ_005718

answers: radiocarbon dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating of beeswax rock art,

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: uranium-series direct dates for rock art in China.

answers: NDQ_005718

answers: vulnerable rock art sites.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: uranium-series direct dates for rock art in China.

text: The site is heavily eroded and it has been suggested that the original crater was slightly larger, at around 20 km diameter. The age of the impact structure is somewhat contentious, in the absence of any radiometric dating. The impact–shocked rocks at the centre of the site are early Mesoproterozoic in age, which gives an absolute maximum possible age for the impact. In the past it has been debated whether the limestones, which are of Middle Cambrian age (ca. 510 Ma) based on comparisons with nearby outcrops of marine limestone in the Georgina Basin, were simply deposited in the crater after its formation, or were actually deformed by the impact event. Depending on the differing points of view, the crater may be of earlier Cambrian or Proterozoic age, or it could be of younger Paleozoic age. The most recent study concludes that the impact most likely happened just before or even during the early stages of deposition of the limestone, suggesting an age of around 509–506 Ma (Middle Cambrian).

text: The site is heavily eroded and it has been suggested that the original crater was slightly larger, at around 20 km diameter. The age of the impact structure is somewhat contentious, in the absence of any

text: radiometric dating

text: . The impact–shocked rocks at the centre of the site are early

text: Mesoproterozoic

text: in age, which gives an absolute maximum possible age for the impact. In the past it has been debated whether the limestones, which are of Middle

text: Cambrian

text: age (ca. 510

text: Ma

text: ) based on comparisons with nearby outcrops of marine limestone in the

text: Georgina Basin

text: , were simply deposited in the crater after its formation, or were actually deformed by the impact event. Depending on the differing points of view, the crater may be of earlier

text: Cambrian

text: or

text: Proterozoic

text: age, or it could be of younger

text: Paleozoic

text: age. The most recent study concludes that the impact most likely happened just before or even during the early stages of deposition of the limestone, suggesting an age of around 509–506

text: Ma

text: (Middle

text: Cambrian

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: The impact–shocked rocks

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating is used for dating human remains

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: The age of the impact structure is somewhat contentious

answers: NDQ_005718

answers: age of the impact structure

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: The impact–shocked rocks

answers: NDQ_005712

answers: early Mesoproterozoic

answers: NDQ_005713

answers: radiometric dating.

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: Middle Cambrian

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: radiometric dating.

answers: NDQ_005718

answers: The age of the impact structure is somewhat contentious,

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: Cross-cutting relationships can also be used in conjunction with radiometric age dating to effect an age bracket for geological materials that cannot be directly dated by radiometric techniques. For example, if a layer of sediment containing a fossil of interest is bounded on the top and bottom by unconformities, where the lower unconformity truncates dike A and the upper unconformity truncates dike B (which penetrates the layer in question), this method can be used. A radiometric age date from crystals in dike A will give the maximum age date for the layer in question and likewise, crystals from dike B will give us the minimum age date. This provides an age bracket, or range of possible ages, for the layer in question.

text: Cross-cutting relationships can also be used in conjunction with

text: radiometric age dating

text: to effect an age bracket for geological materials that cannot be directly dated by radiometric techniques. For example, if a layer of sediment containing a fossil of interest is bounded on the top and bottom by unconformities, where the lower unconformity truncates dike A and the upper unconformity truncates dike B (which penetrates the layer in question), this method can be used. A radiometric age date from crystals in dike A will give the maximum age date for the layer in question and likewise, crystals from dike B will give us the minimum age date. This provides an age bracket, or range of possible ages, for the layer in question.

answers: NDQ_005711

answers: radiometric techniques

answers: NDQ_005712

answers: cross-cutting relationships

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: This provides an age bracket, or range of possible ages, for the layer in question.

answers: NDQ_005718

answers: directly dated by radiometric techniques

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: crystals

answers: NDQ_005712

answers: cannot be directly dated by radiometric techniques.

answers: NDQ_005713

answers: Cross-cutting relationships

answers: NDQ_005714

answers: cannot be directly dated by radiometric techniques.

answers: NDQ_005715

answers: Cross-cutting relationships

answers: NDQ_005716

answers: radiometric techniques.

answers: NDQ_005717

answers: crystals from dike B will give us the minimum age date.

answers: NDQ_005718

answers: directly dated

answers: NDQ_005719

answers: Cross-cutting relationships

answers: NDQ_005720

answers: radiometric age dating

text: Indeed, although a radiocarbon test of material found in this Roman Fort gave a possible date of construction during the Agricolan campaign, its interpretation remains problematic.

text: Indeed, although a radiocarbon test of material found in this Roman Fort gave a possible date of construction during the

text: Agricolan

text: campaign, its interpretation remains problematic.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: its interpretation remains problematic

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: its interpretation remains problematic.

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: its interpretation remains problematic.

answers: NDQ_005718

answers: interpretation

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: its interpretation remains problematic.

text: Since the early years of the twentieth century, absolute dating methods, such as radiometric dating (including potassium/argon, argon/argon, uranium series, and, for very recent fossils, radiocarbon dating) have been used to verify the relative ages obtained by fossils and to provide absolute ages for many fossils. Radiometric dating has shown that the earliest known stromatolites are over 3.4 billion years old.

text: Since the early years of the twentieth century,

text: absolute dating

text: methods, such as

text: radiometric dating

text: (including

text: potassium/argon

text: argon/argon

text: uranium series

text: , and, for very recent fossils,

text: radiocarbon dating

text: ) have been used to verify the relative ages obtained by fossils and to provide absolute ages for many fossils. Radiometric dating has shown that the earliest known stromatolites are over 3.4 billion years old.

answers: NDQ_005711

answers: absolute dating

answers: NDQ_005712

answers: radiocarbon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: argon/argon

answers: NDQ_005718

answers: absolute ages

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: absolute dating methods,

answers: NDQ_005712

answers: absolute dating

answers: NDQ_005713

answers: absolute dating methods,

answers: NDQ_005714

answers: verify the relative ages obtained by fossils

answers: NDQ_005715

answers: Radiometric dating

answers: NDQ_005716

answers: radiocarbon dating)

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: relative ages obtained by fossils

answers: NDQ_005719

answers: radiocarbon dating)

answers: NDQ_005720

answers: Radiometric dating

text: All specimens of Majungasaurus have been recovered from the Maevarano Formation in the Mahajanga Province in northwestern Madagascar. Most of these, including all of the most complete material, came from the Anembalemba Member, although Majungasaurus teeth have also been found in the underlying Masorobe Member and the overlying Miadana Member. While these sediments have not been dated radiometrically, evidence from biostratigraphy and paleomagnetism suggest that they were deposited during the Maastrichtian stage, which lasted from 70 to 66 Ma (million years ago). Majungasaurus teeth are found up until the very end of the Maastrichtian, when all non-avian dinosaurs became extinct.

text: All specimens of Majungasaurus have been recovered from the Maevarano Formation in the

text: Mahajanga Province

text: in northwestern Madagascar. Most of these, including all of the most complete material, came from the Anembalemba Member, although Majungasaurus teeth have also been found in the underlying Masorobe Member and the overlying Miadana Member. While these sediments have not been dated

text: radiometrically

text: , evidence from

text: biostratigraphy

text: and

text: paleomagnetism

text: suggest that they were deposited during the

text: Maastrichtian

text: stage

text: , which lasted from 70 to 66 Ma (million years ago). Majungasaurus teeth are found up until the very end of the Maastrichtian, when all non-avian dinosaurs

text: became extinct

answers: NDQ_005711

answers: radiometrically

answers: NDQ_005712

answers: maastrichtian

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometrically

answers: NDQ_005715

answers: What is the half-life of carbon-14?

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: these sediments have not been dated radiometrically

answers: NDQ_005718

answers: these sediments have not been dated

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: biostratigraphy and paleomagnetism

answers: NDQ_005712

answers: 70 to 66 Ma (million years ago).

answers: NDQ_005713

answers: Maastrichtian

answers: NDQ_005714

answers: radiometrically,

answers: NDQ_005715

answers: Maastrichtian

answers: NDQ_005716

answers: all non-avian dinosaurs became extinct.

answers: NDQ_005717

answers: radiometrically,

answers: NDQ_005718

answers: these sediments have not been dated radiometrically,

answers: NDQ_005719

answers: radiometrically,

answers: NDQ_005720

answers: radiometrically,

text: Other characters occasionally speculate on the pair's relationship. When Donna encourages Josh to ask Joey Lucas on a date, Joey guesses that Donna is attempting to cover her own feelings for Josh through misdirection. During the same episode Josh and Sam Seaborn discuss why Donna was so pushy about asking out Joey; Josh comments that he wonders why Donna wouldn't be jealous to which Sam asked if Josh gets jealous when Donna dates. Josh says he doesn't but does everything in his power to stop or hinder the dates from happening. During her first meeting with Josh, Amy Gardner asks him if he is dating his assistant, and later asks Donna directly, "Are you in love with Josh?", we do not see Donna's answer. When Donna recruits Josh to help her get a date with Jack Reese, Josh's behavior leads Jack to wonder whether he is getting "in between anything".

text: Other characters occasionally speculate on the pair's relationship. When Donna encourages Josh to ask

text: Joey Lucas

text: on a date, Joey guesses that Donna is attempting to cover her own feelings for Josh through misdirection. During the same episode Josh and Sam Seaborn discuss why Donna was so pushy about asking out Joey; Josh comments that he wonders why Donna wouldn't be jealous to which Sam asked if Josh gets jealous when Donna dates. Josh says he doesn't but does everything in his power to stop or hinder the dates from happening. During her first meeting with Josh,

text: Amy Gardner

text: asks him if he is dating his assistant, and later asks Donna directly, "Are you in love with Josh?", we do not see Donna's answer. When Donna recruits Josh to help her get a date with

text: Jack Reese

text: , Josh's behavior leads Jack to wonder whether he is getting "in between anything".

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: what does radiometric dating use

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: do you get jealous when Donna dates

answers: NDQ_005718

answers: we do not see Donna's answer

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Josh comments that he wonders why Donna wouldn't be jealous

answers: NDQ_005712

answers: attempting to cover her own feelings for Josh through misdirection.

answers: NDQ_005713

answers: Josh comments that he wonders why Donna wouldn't be jealous

answers: NDQ_005714

answers: attempting to cover her own feelings for Josh through misdirection.

answers: NDQ_005715

answers: Josh comments that he wonders why Donna wouldn't be jealous

answers: NDQ_005716

answers: we do not see Donna's answer.

answers: NDQ_005717

answers: "in between anything".

answers: NDQ_005718

answers: dates from happening.

answers: NDQ_005719

answers: Josh comments that he wonders why Donna wouldn't be jealous

answers: NDQ_005720

answers: Josh comments that he wonders why Donna wouldn't be jealous

text: A nuclear weapon uses a fissile material to cause a nuclear chain reaction. The most commonly used materials have been uranium 235 (U-235) and plutonium 239 (P-239). Both uranium 233 (U-233) and reactor-grade plutonium have also been used. The amount of uranium or plutonium needed depends on the sophistication of the design, with a simple design requiring approximately 15 kg of uranium or 6 kg of plutonium and a sophisticated design requiring as little as 9 kg of uranium or 2 kg of plutonium. Plutonium is almost nonexistent in nature, and natural uranium is about 99.3% uranium 238 (U-238) and 0.7% U-235. Therefore, to make a weapon, either uranium must be enriched, or plutonium must be produced. Uranium enrichment is also frequently necessary for nuclear power. For this reason, uranium enrichment is a dual-use technology, a technology which "can be used both for civilian and for military purposes". Key strategies to prevent proliferation of nuclear arms include limiting the number of operating uranium enrichment plants and controlling the export of nuclear technology and fissile material.

text: A

text: nuclear weapon

text: uses a

text: fissile material

text: to cause a

text: nuclear chain reaction

text: . The most commonly used materials have been

text: uranium 235

text: (U-235) and

text: plutonium 239

text: (P-239). Both

text: uranium 233

text: (U-233) and

text: reactor-grade plutonium

text: have also been used. The amount of uranium or plutonium needed depends on the sophistication of the design, with a simple design requiring approximately 15 kg of uranium or 6 kg of plutonium and a sophisticated design requiring as little as 9 kg of uranium or 2 kg of plutonium. Plutonium is almost nonexistent in nature, and natural uranium is about 99.3%

text: uranium 238

text: (U-238) and 0.7% U-235. Therefore, to make a weapon, either uranium must be

text: enriched

text: , or plutonium must be produced. Uranium enrichment is also frequently necessary for

text: nuclear power

text: . For this reason, uranium enrichment is a

text: dual-use technology

text: , a technology which "can be used both for civilian and for military purposes". Key strategies to prevent

text: proliferation of nuclear arms

text: include limiting the number of operating uranium enrichment plants and controlling the export of

text: nuclear technology

text: and

text: fissile material

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Plutonium is almost nonexistent in nature

answers: NDQ_005713

answers: unanswerable

answers: NDQ_005714

answers: Plutonium is almost nonexistent in nature

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: plutonium

answers: NDQ_005717

answers: Plutonium is almost nonexistent

answers: NDQ_005718

answers: Plutonium is almost nonexistent in nature

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: nature,

answers: NDQ_005712

answers: Plutonium is almost nonexistent in nature,

answers: NDQ_005713

answers: plutonium 239 (P-239).

answers: NDQ_005714

answers: Plutonium is almost nonexistent in nature,

answers: NDQ_005715

answers: uranium 235

answers: NDQ_005716

answers: nuclear chain reaction.

answers: NDQ_005717

answers: Plutonium is almost nonexistent in nature,

answers: NDQ_005718

answers: Plutonium is almost nonexistent in nature,

answers: NDQ_005719

answers: uranium 235

answers: NDQ_005720

answers: uranium 235

text: Caves in Batadomba lena, 460 m above sea level in the foothills of Sri Pada (Adam's Peak), have also yielded several important ancient remains. The first excavation of the cave floor in the late 1930s unearthed skeletal fragments of a child and several adults. Excavations in 1981 yielded more complete human skeletons from the sixth stratum (a layer of internally consistent sedimentary soil or rock) which were radiocarbon dated from associated charcoal samples to 16,000 BP. Excavations of the seventh stratum in the following year produced further human remains along with charcoal and 17 geometric microliths, i.e. 1–4 cm long triangular, trapezoid or lunate stone tools made of flint or chert that form, among other artifacts, the end points of hunting weapons such as spears and arrows. Radiometric tests on the charcoal placed the tools to around 28,500 BP.

text: Caves in

text: Batadomba lena

text: , 460 m above sea level in the foothills of

text: Sri Pada

text: Adam's Peak

text: ), have also yielded several important ancient remains. The first excavation of the cave floor in the late 1930s unearthed skeletal fragments of a child and several adults. Excavations in 1981 yielded more complete human skeletons from the sixth

text: stratum

text: (a layer of internally consistent sedimentary soil or rock) which were radiocarbon dated from associated charcoal samples to 16,000 BP. Excavations of the seventh stratum in the following year produced further human remains along with charcoal and 17 geometric

text: microlith

text: s, i.e. 1–4 cm long triangular, trapezoid or lunate stone tools made of flint or chert that form, among other artifacts, the end points of hunting weapons such as spears and arrows. Radiometric tests on the charcoal placed the tools to around 28,500 BP.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: charcoal samples to 16,000 BP

answers: NDQ_005715

answers: How long does carbon-14 decay to carbon-12?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dated from associated charcoal samples

answers: NDQ_005718

answers: charcoal samples

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon dated from associated charcoal samples

answers: NDQ_005712

answers: radiocarbon dated from associated charcoal samples to 16,000 BP.

answers: NDQ_005713

answers: radiocarbon dated from associated charcoal samples to 16,000 BP.

answers: NDQ_005714

answers: radiocarbon dated from associated charcoal samples to 16,000 BP.

answers: NDQ_005715

answers: 16,000 BP.

answers: NDQ_005716

answers: radiocarbon dated

answers: NDQ_005717

answers: radiocarbon dated from associated charcoal samples to 16,000 BP.

answers: NDQ_005718

answers: Radiometric tests on the charcoal placed the tools to around 28,500 BP.

answers: NDQ_005719

answers: radiocarbon dated from associated charcoal samples to 16,000 BP.

answers: NDQ_005720

answers: radiocarbon dated from associated charcoal samples to 16,000 BP.

text: The Later Stone Age sequence has been radiocarbon dated to 2000–290 years BP, while the Middle Stone Age sequence is dated to ca. 101,000-70,000 years ago through a number of methods, including: thermo-luminescence (TL), optically stimulated luminescence (OSL), uranium-thorium series (U/Th) and electron spin resonance (ESR). The lowest levels of the M3 phase has a preliminary age of >130,000 years ago, while the unexcavated sediments below these levels remains undated (June 2013).

text: The Later Stone Age sequence has been

text: radiocarbon dated

text: to 2000–290 years BP, while the Middle Stone Age sequence is dated to ca. 101,000-70,000 years ago through a number of methods, including: thermo-luminescence (TL), optically stimulated luminescence (OSL), uranium-thorium series (U/Th) and electron spin resonance (ESR). The lowest levels of the M3 phase has a preliminary age of >130,000 years ago, while the unexcavated sediments below these levels remains undated (June 2013).

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: thermo-luminescence

answers: NDQ_005718

answers: unexcavated sediments

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: 101,000-70,000 years ago

answers: NDQ_005713

answers: electron spin resonance (ESR).

answers: NDQ_005714

answers: radiocarbon dated to 2000–290 years BP,

answers: NDQ_005715

answers: 2000–290 years BP,

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: thermo-luminescence

answers: NDQ_005718

answers: unexcavated sediments below these levels remains undated

answers: NDQ_005719

answers: thermo-luminescence

answers: NDQ_005720

answers: uranium-thorium series

text: In 1982, the S.Tu.R.P. group published the list of tests to be performed on the shroud; these aimed to identify how the image was impressed onto the cloth, to verify the relic's purported origin, and to identify better-suited conservation methods. However, a disagreement between the S.Tu.R.P. group and the candidate laboratories devolved into a P.R. rift: the S.Tu.R.P. group expected to perform the radiometric examination under its own aegis and after the other examinations had been completed, while the laboratories considered radio-carbon dating to be the priority test, which should be completed at the detriment of other tests, if necessary.

text: In 1982, the S.Tu.R.P. group published the list of tests to be performed on the shroud; these aimed to identify how the image was impressed onto the cloth, to verify the relic's purported origin, and to identify better-suited conservation methods. However, a disagreement between the S.Tu.R.P. group and the candidate laboratories devolved into a P.R. rift: the S.Tu.R.P. group expected to perform the

text: radiometric examination

text: under its own aegis and after the other examinations had been completed, while the laboratories considered radio-carbon dating to be the priority test, which should be completed at the detriment of other tests, if necessary.

answers: NDQ_005711

answers: carbon

answers: NDQ_005712

answers: radio-carbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radioactive

answers: NDQ_005715

answers: radio-carbon dating

answers: NDQ_005716

answers: radiometric examination

answers: NDQ_005717

answers: radio-carbon dating to be the priority test, which should be completed at the detriment of other tests, if necessary.

answers: NDQ_005718

answers: should be completed at the detriment of other tests, if necessary

answers: NDQ_005719

answers: radio-carbon

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radio-carbon

answers: NDQ_005712

answers: radio-carbon

answers: NDQ_005713

answers: radio-carbon

answers: NDQ_005714

answers: radio-carbon dating to be the priority test,

answers: NDQ_005715

answers: radio-carbon

answers: NDQ_005716

answers: radio-carbon dating

answers: NDQ_005717

answers: radio-carbon

answers: NDQ_005718

answers: other tests,

answers: NDQ_005719

answers: radio-carbon

answers: NDQ_005720

answers: radio-carbon dating

text: There are 24 known isotopes of potassium, three of which occur naturally:  (93.3%),  (0.0117%), and  (6.7%). Naturally occurring  has a half-life of 1.250×10 years. It decays to stable  by electron capture or positron emission (11.2%) or to stable  by beta decay (88.8%). The decay of  to  is the basis of a common method for dating rocks. The conventional K-Ar dating method depends on the assumption that the rocks contained no argon at the time of formation and that all the subsequent radiogenic argon () was quantitatively retained. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic  that has accumulated. The minerals best suited for dating include biotite, muscovite, metamorphic hornblende, and volcanic feldspar; whole rock samples from volcanic flows and shallow instrusives can also be dated if they are unaltered. Apart from dating, potassium isotopes have been used as tracers in studies of weathering and for nutrient cycling studies because potassium is a macronutrient required for life.

text: There are 24 known

text: isotope

text: s of potassium, three of which occur naturally:  (93.3%),  (0.0117%), and  (6.7%). Naturally occurring  has a

text: half-life

text: of 1.250×10 years. It decays to stable  by

text: electron capture

text: or

text: positron emission

text: (11.2%) or to stable  by

text: beta decay

text: (88.8%). The decay of  to  is the basis of a common method for dating rocks. The conventional

text: K-Ar dating method

text: depends on the assumption that the rocks contained no argon at the time of formation and that all the subsequent radiogenic argon () was quantitatively retained.

text: Mineral

text: s are dated by measurement of the concentration of potassium and the amount of radiogenic  that has accumulated. The minerals best suited for dating include

text: biotite

text: muscovite

text: , metamorphic

text: hornblende

text: , and volcanic

text: feldspar

text: whole rock

text: samples from volcanic flows and shallow

text: instrusives

text: can also be dated if they are unaltered. Apart from dating, potassium isotopes have been used as

text: tracers

text: in studies of

text: weathering

text: and for

text: nutrient cycling

text: studies because potassium is a

text: macronutrient

text: required for

text: life

answers: NDQ_005711

answers: decay of to

answers: NDQ_005712

answers: minerals are dated by measurement of potassium and the amount of radiogenic that has accumulated

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium isotopes have been used as tracers

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: minerals are dated by measurement of the concentration of potassium and the amount of radiogenic that has accumulated

answers: NDQ_005718

answers: half-life of 1.250 10 years

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: concentration of potassium and the amount of radiogenic that has accumulated.

answers: NDQ_005712

answers: if they are unaltered.

answers: NDQ_005713

answers: The decay of to is the basis of a common method for dating rocks.

answers: NDQ_005714

answers: potassium is a macronutrient required for life.

answers: NDQ_005715

answers: 1.250<unk>10 years.

answers: NDQ_005716

answers: radiogenic argon

answers: NDQ_005717

answers: the assumption that the rocks contained no argon at the time of formation

answers: NDQ_005718

answers: quantitatively retained.

answers: NDQ_005719

answers: K-Ar dating

answers: NDQ_005720

answers: K-Ar dating method

text: Zircon has played an important role during the evolution of radiometric dating. Zircons contain trace amounts of uranium and thorium (from 10 ppm up to 1 wt%) and can be dated using several modern analytical techniques. Because zircons can survive geologic processes like erosion, transport, even high-grade metamorphism, they contain a rich and varied record of geological processes. Currently, zircons are typically dated by uranium-lead (U-Pb), fission-track, and U+Th/He techniques. Zircons in sedimentary rock can identify the sediment source.

text: Zircon has played an important role during the evolution of

text: radiometric dating

text: . Zircons contain trace amounts of uranium and thorium (from 10

text: ppm

text: up to 1 wt%) and can be dated using several modern analytical techniques. Because zircons can survive geologic processes like

text: erosion

text: , transport, even high-grade

text: metamorphism

text: , they contain a rich and varied record of geological processes. Currently, zircons are typically dated by

text: uranium-lead

text: (U-Pb),

text: fission-track

text: , and U+Th/He techniques.

text: Zircons in sedimentary rock

text: can identify the sediment source.

answers: NDQ_005711

answers: zircons

answers: NDQ_005712

answers: zircons

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Zircons contain trace amounts of uranium

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: Zircons contain trace amounts of uranium and thorium

answers: NDQ_005718

answers: zircons in sedimentary rock can identify the sediment source

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: modern analytical techniques.

answers: NDQ_005712

answers: zircons can survive geologic processes

answers: NDQ_005713

answers: Zircon

answers: NDQ_005714

answers: Zircon has played an important role during the evolution of radiometric dating.

answers: NDQ_005715

answers: Zircon

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: U+Th/He techniques.

answers: NDQ_005718

answers: erosion, transport, even high-grade metamorphism,

answers: NDQ_005719

answers: uranium-lead

answers: NDQ_005720

answers: uranium-lead

text: The question before the court was whether or not eligible retirees could be assigned to an operator after the October 1st date specified in the Act.  If the retirees could not be assigned to an operator, the company they would have been assigned to would be free of obligation. The mining companies argued the date in the Act limited the commissioner's ability to assign eligible retirees to an operator.  The commissioner argued the Act had been set to spur timely completion and that assignments could be made after that date.

text: The question before the court was whether or not eligible retirees could be assigned to an operator after the October 1st date specified in the Act.  If the retirees could not be assigned to an operator, the company they would have been assigned to would be free of obligation. The mining companies argued the date in the Act limited the commissioner's ability to assign eligible retirees to an operator.  The commissioner argued the Act had been set to spur timely completion and that assignments could be made after that date.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for these materials

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: potassium-argon dating

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: are useful for very young materials

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: October 1st

answers: NDQ_005712

answers: the Act had been set to spur timely completion

answers: NDQ_005713

answers: October 1st

answers: NDQ_005714

answers: the Act had been set to spur timely completion

answers: NDQ_005715

answers: October 1st

answers: NDQ_005716

answers: October 1st

answers: NDQ_005717

answers: October 1st

answers: NDQ_005718

answers: commissioner's ability to assign eligible retirees to an operator.

answers: NDQ_005719

answers: October 1st

answers: NDQ_005720

answers: October 1st

text: Many dates have been given for the Taupo eruption. One estimated date is 181 CE from ice cores in Greenland and Antarctica. It is possible that the meteorological phenomena described by Fan Ye in China and by Herodian in Rome were due to this eruption, which would give a date of exactly to 186 however ash from volcanic activity does not normally cross hemispheres, and recent radiocarbon dating by R. Sparks has put the date at 233 CE +/- 13 (95% confidence).

text: Many dates have been given for the Taupo eruption. One estimated date is 181 CE from

text: ice core

text: s in

text: Greenland

text: and

text: Antarctica

text: . It is possible that the

text: meteorological

text: phenomena described by

text: Fan Ye

text: in China and by

text: Herodian

text: in Rome were due to this eruption, which would give a date of exactly to 186 however ash from volcanic activity does not normally cross hemispheres, and recent radiocarbon dating by R. Sparks has put the date at 233 CE +/- 13 (95% confidence).

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: radiocarbon dating

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 233 CE +/- 13

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 233 CE +/- 13

answers: NDQ_005718

answers: ash from volcanic activity does not normally cross hemispheres,

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: 233 CE +/- 13

text: Dates determined using radiocarbon dating come in two kinds: uncalibrated (also called Libby or raw) and calibrated (also called Cambridge) dates. Uncalibrated radiocarbon dates should be clearly noted as such by "uncalibrated years BP", because they are not identical to calendar dates. This has to do with the fact that the level of atmospheric radiocarbon (carbon-14 or C) has not been strictly constant during the span of time that can be radiocarbon-dated. Uncalibrated radiocarbon ages can be converted to calendar dates by means of calibration curves based on comparison of raw radiocarbon dates of samples independently dated by other methods, such as dendrochronology (dating on the basis of tree growth-rings) and stratigraphy (dating on the basis of sediment layers in mud or sedimentary rock). Such calibrated dates are expressed as cal BP, where "cal" indicates "calibrated years", or "calendar years", before 1950.

text: Dates determined using radiocarbon dating come in two kinds: uncalibrated (also called Libby or raw) and calibrated (also called Cambridge) dates. Uncalibrated radiocarbon dates should be clearly noted as such by "uncalibrated years BP", because they are not identical to calendar dates. This has to do with the fact that the level of atmospheric radiocarbon (

text: or C) has not been strictly constant during the span of time that can be radiocarbon-dated. Uncalibrated radiocarbon ages can be converted to calendar dates by means of

text: calibration curves

text: based on comparison of raw radiocarbon dates of samples independently dated by other methods, such as

text: dendrochronology

text: (dating on the basis of tree growth-rings) and

text: stratigraphy

text: (dating on the basis of sediment layers in mud or sedimentary rock). Such calibrated dates are expressed as cal BP, where "cal" indicates "calibrated years", or "calendar years", before 1950.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: calibrated

answers: NDQ_005713

answers: radiocarbon dating

answers: NDQ_005714

answers: level of atmospheric radiocarbon (carbon-14 or C) has not been strictly constant during the span of time that can be radiocarbon-dated

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: calibrated

answers: NDQ_005717

answers: calibrated

answers: NDQ_005718

answers: uncalibrated radiocarbon ages can be converted to calendar dates

answers: NDQ_005719

answers: uncalibrated

answers: NDQ_005720

answers: radiocarbon dating

answers: NDQ_005711

answers: tree growth-rings)

answers: NDQ_005712

answers: the level of atmospheric radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: has not been strictly constant

answers: NDQ_005715

answers: the level of atmospheric radiocarbon

answers: NDQ_005716

answers: the level of atmospheric radiocarbon

answers: NDQ_005717

answers: calibration curves

answers: NDQ_005718

answers: level of atmospheric radiocarbon

answers: NDQ_005719

answers: dendrochronology

answers: NDQ_005720

answers: radiocarbon dating come in two kinds: uncalibrated

text: The beds display a pronounced cyclicity, with the precession, obliquity, and eccentricity orbital components all clearly detectable. This enables the beds to be internally dated with a high degree of accuracy, and astrochronological dates agree very well with radiometric dates.

text: The beds display a pronounced

text: cyclicity

text: , with the precession, obliquity, and eccentricity orbital components all clearly detectable. This enables the beds to be internally dated with a high degree of accuracy, and

text: astrochronological

text: dates agree very well with

text: radiometric

text: dates.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: astrochronological

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dates

answers: NDQ_005717

answers: This enables the beds to be internally dated with a high degree of accuracy

answers: NDQ_005718

answers: internal dated

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: internally dated with a high degree of accuracy,

answers: NDQ_005712

answers: cyclicity,

answers: NDQ_005713

answers: astrochronological dates agree very well with radiometric dates.

answers: NDQ_005714

answers: high degree of accuracy,

answers: NDQ_005715

answers: astrochronological dates agree very well with radiometric dates.

answers: NDQ_005716

answers: astrochronological dates agree very well with radiometric dates.

answers: NDQ_005717

answers: cyclicity,

answers: NDQ_005718

answers: accuracy,

answers: NDQ_005719

answers: astrochronological dates agree very well with radiometric dates.

answers: NDQ_005720

answers: astrochronological dates agree very well with radiometric dates.

text: The decay of K to Ar enables a commonly used method for dating rocks. The conventional K-Ar dating method depends on the assumption that the rocks contained no argon at the time of formation and that all the subsequent radiogenic argon (i.e., Ar) was quantitatively retained. Minerals are dated by measurement of the concentration of potassium and the amount of radiogenic Ar that has accumulated.

text: The decay of K to Ar enables a commonly used method for dating rocks. The conventional

text: K-Ar dating method

text: depends on the assumption that the rocks contained no argon at the time of formation and that all the subsequent radiogenic argon (i.e., Ar) was quantitatively retained.

text: Mineral

text: s are dated by measurement of the concentration of potassium and the amount of radiogenic Ar that has accumulated.

answers: NDQ_005711

answers: decay

answers: NDQ_005712

answers: minerals are dated by measurement of the concentration of potassium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: the decay of K to Ar

answers: NDQ_005715

answers: NDQ_005716

answers: decay

answers: NDQ_005717

answers: The decay of K to Ar enables a commonly used method for dating rocks

answers: NDQ_005718

answers: the assumption that the rocks contained no argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: NDQ_005711

answers: concentration of potassium and the amount of radiogenic Ar that has accumulated.

answers: NDQ_005712

answers: the rocks contained no argon at the time of formation

answers: NDQ_005713

answers: decay of K to Ar enables a commonly used method for dating rocks.

answers: NDQ_005714

answers: radiogenic argon

answers: NDQ_005715

answers: K to Ar enables a commonly used method for dating rocks.

answers: NDQ_005716

answers: dating rocks.

answers: NDQ_005717

answers: the assumption that the rocks contained no argon at the time of formation

answers: NDQ_005718

answers: the rocks contained no argon at the time of formation

answers: NDQ_005719

answers: Minerals

answers: NDQ_005720

answers: radiogenic Ar that has accumulated.

text: Spectral data acquired by satellite sensors are influenced by a number of factors, such as atmospheric absorption and scattering, sensor-target-illumination geometry, sensor calibration, and image data processing procedures, which tend to change through times (Teillet, 1986). Targets in multi-date scenes are extremely variable and have been nearly impossible to compare in an automated mode (Kim and Elman, 1990). In order to detect genuine landscape changes as revealed by changes in surface reflectance from multi-date satellite images, it is necessary to carry out radiometric correction. Two approaches to radiometric correction are possible: absolute and relative (Lo and Yang, 1998). The absolute approach requires the use of ground measurements at the time of data acquisition for atmospheric correction and sensor calibration. This is not only costly but also impractical when archival satellite image data are used for change analysis (Hall et al., 1991). The relative approach to radiometric correction, known as relative radiometric normalization (RRN), ispreferred because no in situ atmospheric data at the time of satellite overpasses are required. This method involves normalizing or rectifying the intensities or digital numbers (DN) of multi-date images bandby-band to a reference image selected by the analyst. The normalized images would appear as if they were acquired with the same sensor under similar atmospheric and illumination conditions to those of the reference image.

answers: NDQ_005711

answers: radiometric correction

answers: NDQ_005712

answers: archival

answers: NDQ_005713

answers: unanswerable

answers: NDQ_005714

answers: relative radiometric normalization (RRN) ispreferred

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiometric correction

answers: NDQ_005717

answers: Targets in multi-date scenes are extremely variable and have been nearly impossible to compare in an automated mode

answers: NDQ_005718

answers: Targets in multi-date scenes are extremely variable

answers: NDQ_005719

answers: relative radiometric normalization

answers: NDQ_005720

answers: NDQ_005711

answers: changes in surface reflectance from multi-date satellite images,

answers: NDQ_005712

answers: archival

answers: NDQ_005713

answers: relative radiometric normalization

answers: NDQ_005714

answers: no in situ atmospheric data at the time of satellite overpasses

answers: NDQ_005715

answers: relative radiometric normalization

answers: NDQ_005716

answers: radiometric correction.

answers: NDQ_005717

answers: radiometric correction.

answers: NDQ_005718

answers: Targets in multi-date scenes are extremely variable

answers: NDQ_005719

answers: relative radiometric normalization

answers: NDQ_005720

answers: relative radiometric normalization

text: Ainigmapsychops inexspectatus is known only from one fossil, the part side of the holotype, specimen number SRUI 99-96-76, which is housed in the collections of the Stonerose Interpretive Center in Republic, Washington.  The specimen is preserved as a compression fossil in silty yellow to grayish shale, which was recovered from outcrops of the Tom Thumb Tuff member of the Klondike Mountain Formation.  The formation is approximately Early Eocene, Ypresian in age, being radiometrically dated as .  Ainigmapsychops was first studied by the paleoentomologists Vladimir N. Makarkin of the Far Eastern Branch of the Russian Academy of Sciences and S. Bruce Archibald from Simon Fraser University in Burnaby, British Columbia.  Their 2014 type description of the new genus and species was published in the online journal Zootaxa.  The genus name Ainigmapsychops was coined by the researchers as a combination of the silky lacewing type genus Psychopsis and the Greek word Ainigma meaning "riddle" or "enigma", which is in reference to the unusual nature of the wing vein structure.  The specific epithet inexspectatus is the Latin word meaning "unexpected, unlooked for", alluding to the serendipitous find of the wing.

text: Ainigmapsychops inexspectatus is known only from one fossil, the

text: part side

text: of the

text: holotype

text: , specimen number SRUI 99-96-76, which is housed in the collections of the

text: Stonerose Interpretive Center

text: in

text: Republic, Washington

text: .  The specimen is preserved as a

text: compression fossil

text: in silty yellow to grayish

text: shale

text: , which was recovered from outcrops of the Tom Thumb Tuff member of the

text: Klondike Mountain Formation

text: .  The formation is approximately

text: Early Eocene

text: Ypresian

text: in age, being radiometrically dated as .  Ainigmapsychops was first studied by the paleoentomologists Vladimir N. Makarkin of the

text: Far Eastern Branch of the Russian Academy of Sciences

text: and S. Bruce Archibald from

text: Simon Fraser University

text: in

text: Burnaby, British Columbia

text: .  Their 2014

text: type description

text: of the new genus and species was published in the online journal

text: Zootaxa

text: .  The genus name Ainigmapsychops was coined by the researchers as a combination of the silky lacewing type genus

text: Psychopsis

text: and the

text: Greek

text: word Ainigma meaning "riddle" or "enigma", which is in reference to the unusual nature of the wing vein structure.  The

text: specific epithet

text: inexspectatus is the

text: Latin

text: word meaning "unexpected, unlooked for", alluding to the

text: serendipitous

text: find of the wing.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: Early Eocene

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: radiometrically dated as

answers: NDQ_005716

answers: radiometrically

answers: NDQ_005717

answers: radiometrically dated as

answers: NDQ_005718

answers: Ypresian in age

answers: NDQ_005719

answers: radiometrically dated as

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Early Eocene, Ypresian

answers: NDQ_005712

answers: Early Eocene, Ypresian

answers: NDQ_005713

answers: Early Eocene, Ypresian

answers: NDQ_005714

answers: radiometrically dated

answers: NDQ_005715

answers: Ainigmapsychops inexspectatus

answers: NDQ_005716

answers: radiometrically dated

answers: NDQ_005717

answers: radiometrically dated as.

answers: NDQ_005718

answers: Ypresian in age,

answers: NDQ_005719

answers: radiometrically dated

answers: NDQ_005720

answers: radiometrically dated

text: The age of the Earth is 4.54 ± 0.05 billion years  This dating is based on evidence from radiometric age dating of meteorite material and is consistent with the radiometric ages of the oldest-known terrestrial and lunar samples.

text: The age of the Earth is 4.54 ± 0.05

text: billion

text: years  This dating is based on evidence from

text: radiometric age dating

text: of

text: meteorite

text: material and is consistent with the radiometric ages of the oldest-known terrestrial and

text: lunar

text: samples

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: meteorite material

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric age dating

answers: NDQ_005718

answers: radiometric age dating of meteorite material

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: oldest-known terrestrial and lunar samples.

answers: NDQ_005712

answers: oldest-known terrestrial and lunar samples.

answers: NDQ_005713

answers: radiometric age dating of meteorite material

answers: NDQ_005714

answers: radiometric ages of the oldest-known terrestrial and lunar samples.

answers: NDQ_005715

answers: The age of the Earth is 4.54 <unk> 0.05 billion years

answers: NDQ_005716

answers: radiometric age dating

answers: NDQ_005717

answers: radiometric age dating of meteorite material

answers: NDQ_005718

answers: ages of the oldest-known terrestrial and lunar samples.

answers: NDQ_005719

answers: radiometric age dating of meteorite material

answers: NDQ_005720

answers: radiometric age dating of meteorite material

text: Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.

text: Different methods of radiometric dating vary in the timescale over which they are accurate and the materials to which they can be applied.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating is inaccurate

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: what is the timescale over which it is accurate

answers: NDQ_005718

answers: timescale over which they are accurate

answers: NDQ_005719

answers: uranium

answers: NDQ_005720

answers: radiometric

answers: NDQ_005711

answers: radiometric dating vary in the timescale over which they are accurate

answers: NDQ_005712

answers: timescale

answers: NDQ_005713

answers: radiometric dating vary in the timescale over which they are accurate

answers: NDQ_005714

answers: timescale over which they are accurate

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: the materials to which they can be applied.

answers: NDQ_005718

answers: timescale over which they are accurate

answers: NDQ_005719

answers: the materials to which they can be applied.

answers: NDQ_005720

answers: radiometric dating

text: Numerous radiocarbon dates have been collected from the sediments, which fill the basins of Carolina bays. The majority of these samples, from which these dates were obtained, were collected from cores of undisturbed sediments that filled Carolina bays in North and South Carolina. These cores were collected to reconstruct region paleoenvironmental records using pollen, diatoms, and other fossils found in the distinctly and conformably layered sediments that fill the Carolina bays. Additional radiocarbon dates have been obtained from organic matter collected from the undisturbed sediments filling Carolina bays by Bliley and Burney, Mixon and Pilkey, Thom, and Kaczorowski. Many radiocarbon dates, which were obtained from organic matter preserved within undisturbed sediments are greater than 14,000 BP radiocarbon in age. The finite radiocarbon dates range in age from 440 ± 50 to 27,700 ±2,600 BP radiocarbon in age. Some samples are so old, they contained insufficient radiocarbon for dating, which results in "greater than" dates. For example, samples from sediments filling Carolina bays have been dated at greater than 38,000 to 49,550 BP radiocarbon years.

text: Numerous radiocarbon dates have been collected from the sediments, which fill the basins of Carolina bays. The majority of these samples, from which these dates were obtained, were collected from cores of undisturbed sediments that filled Carolina bays in North and South Carolina. These cores were collected to reconstruct region paleoenvironmental records using pollen, diatoms, and other fossils found in the distinctly and conformably layered sediments that fill the Carolina bays. Additional radiocarbon dates have been obtained from organic matter collected from the undisturbed sediments filling Carolina bays by Bliley and Burney, Mixon and Pilkey, Thom, and Kaczorowski. Many radiocarbon dates, which were obtained from organic matter preserved within undisturbed sediments are greater than 14,000

text: BP

text: radiocarbon in age. The finite radiocarbon dates range in age from 440 ± 50 to 27,700 ±2,600 BP radiocarbon in age. Some samples are so old, they contained insufficient radiocarbon for dating, which results in "greater than" dates. For example, samples from sediments filling Carolina bays have been dated at greater than 38,000 to 49,550 BP radiocarbon years.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon is a non-radioactive element

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains and artifacts

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 440  50 to 27,700  2,600 BP radiocarbon in age

answers: NDQ_005718

answers: Some samples are so old, they contained insufficient radiocarbon

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Some samples are so old, they contained insufficient radiocarbon

answers: NDQ_005713

answers: 14,000 BP radiocarbon in age.

answers: NDQ_005714

answers: paleoenvironmental records

answers: NDQ_005715

answers: 14,000 BP

answers: NDQ_005716

answers: fossils

answers: NDQ_005717

answers: 14,000 BP radiocarbon in age.

answers: NDQ_005718

answers: Some samples are so old, they contained insufficient radiocarbon for dating,

answers: NDQ_005719

answers: 440 <unk> 50

answers: NDQ_005720

answers: 14,000 BP radiocarbon

text: Radiocarbon dating was first used in 1940. Beginning in 1954, metrologists established 1950 as the origin year for the BP scale for use with radiocarbon dating, using a 1950-based reference sample of oxalic acid. According to scientist A. Currie Lloyd:The year 1950 was chosen because it was the standard astronomical epoch at that time. It also marked the publication of the first radiocarbon dates in December 1949, and 1950 also antedates large scale atmospheric testing of nuclear weapons, which altered the global ratio of carbon-14 to carbon-12.

text: Radiocarbon dating was first used in 1940. Beginning in 1954,

text: metrologist

text: s established 1950 as the origin year for the BP scale for use with

text: radiocarbon dating

text: , using a 1950-based reference sample of

text: oxalic acid

text: . According to scientist A. Currie Lloyd:The year 1950 was chosen because it was the standard

text: astronomical epoch

text: at that time. It also marked the publication of the first radiocarbon dates in December 1949, and 1950 also antedates large scale

text: atmospheric testing of nuclear weapons

text: , which altered the global ratio of

text: to

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: the global ratio of carbon-14 to carbon-12

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating was first used in 1940

answers: NDQ_005718

answers: large scale atmospheric testing of nuclear weapons

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon dating was first used in 1940.

answers: NDQ_005714

answers: large scale atmospheric testing of nuclear weapons,

answers: NDQ_005715

answers: 1950 also antedates large scale atmospheric testing of nuclear weapons,

answers: NDQ_005716

answers: radiocarbon dating,

answers: NDQ_005717

answers: 1950-based reference sample of oxalic acid.

answers: NDQ_005718

answers: antedates large scale atmospheric testing of nuclear weapons,

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating was first used in 1940.

text: Bipedalism evolved more than once in archosaurs, the group that includes both dinosaurs and crocodilians. All dinosaurs are thought to be descended from a fully bipedal ancestor, perhaps similar to Eoraptor.  Bipedal movement also re-evolved in a number of other dinosaur lineages such as the iguanodons. Some extinct members of the crocodilian line, a sister group to the dinosaurs and birds, also evolved bipedal forms - a crocodile relative from the triassic, Effigia okeeffeae, is thought to be bipedal.  Pterosaurs were previously thought to have been bipedal, but recent trackways have all shown quadrupedal locomotion. Bipedalism also evolved independently among the dinosaurs. Dinosaurs diverged from their archosaur ancestors approximately 230 million years ago during the Middle to Late Triassic period, roughly 20 million years after the Permian-Triassic extinction event wiped out an estimated 95% of all life on Earth. Radiometric dating of fossils from the early dinosaur genus Eoraptor establishes its presence in the fossil record at this time. Paleontologists suspect Eoraptor resembles the common ancestor of all dinosaurs; if this is true, its traits suggest that the first dinosaurs were small, bipedal predators. The discovery of primitive, dinosaur-like ornithodirans such as Marasuchus and Lagerpeton in Argentinian Middle Triassic strata supports this view; analysis of recovered fossils suggests that these animals were indeed small, bipedal predators.

text: Bipedalism evolved more than once in

text: archosaurs

text: , the group that includes both dinosaurs and

text: crocodilia

text: ns. All dinosaurs are thought to be descended from a fully bipedal ancestor, perhaps similar to

text: Eoraptor

text: .  Bipedal movement also re-evolved in a number of other

text: dinosaur

text: lineages such as the

text: iguanodon

text: s. Some extinct members of the

text: crocodilia

text: n line, a sister group to the dinosaurs and birds, also evolved bipedal forms - a

text: crocodile

text: relative from the

text: triassic

text: Effigia okeeffeae

text: , is thought to be bipedal.

text: Pterosaur

text: s were previously thought to have been bipedal, but recent trackways have all shown quadrupedal locomotion. Bipedalism also evolved independently among the dinosaurs. Dinosaurs diverged from their

text: archosaur

text: ancestors approximately 230 million years ago during the Middle to Late

text: Triassic

text: period, roughly 20 million years after the

text: Permian-Triassic extinction event

text: wiped out an estimated 95% of all life on Earth.

text: Radiometric dating

text: of fossils from the early dinosaur

text: genus

text: Eoraptor

text: establishes its presence in the fossil record at this time. Paleontologists suspect Eoraptor resembles the

text: common ancestor

text: of all dinosaurs; if this is true, its traits suggest that the first dinosaurs were small, bipedal predators. The discovery of primitive, dinosaur-like ornithodirans such as

text: Marasuchus

text: and

text: Lagerpeton

text: in

text: Argentinian

text: Middle Triassic

text: strata supports this view; analysis of recovered fossils suggests that these animals were indeed small, bipedal predators.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: Middle to Late Triassic

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: How long does it take for carbon-14 to decay?

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: fossil record

answers: NDQ_005712

answers: Middle to Late Triassic

answers: NDQ_005713

answers: 20 million years

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: Middle Triassic

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: Radiometric dating

answers: NDQ_005718

answers: fossil record

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: primitive, dinosaur-like

text: The existence of two 'parallel' uranium-lead decay routes (U to Pb and U to Pb) leads to multiple dating techniques within the overall U–Pb system. The term U–Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below).

text: The existence of two 'parallel' uranium-lead decay routes (U to Pb and U to Pb) leads to multiple dating techniques within the overall U–Pb system. The term U–Pb dating normally implies the coupled use of both decay schemes in the 'concordia diagram' (see below).

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: U to Pb

answers: NDQ_005713

answers: NDQ_005714

answers: uranium-lead decay

answers: NDQ_005715

answers: NDQ_005716

answers: uranium decay

answers: NDQ_005717

answers: The term U–Pb dating normally implies the coupled use of both decay schemes

answers: NDQ_005718

answers: multiple dating techniques

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-lead decay routes

answers: NDQ_005712

answers: U–Pb system.

answers: NDQ_005713

answers: U–Pb dating normally implies the coupled use of both decay schemes

answers: NDQ_005714

answers: uranium-lead decay routes

answers: NDQ_005715

answers: The existence of two 'parallel' uranium-lead

answers: NDQ_005716

answers: dating

answers: NDQ_005717

answers: coupled use of both decay schemes

answers: NDQ_005718

answers: multiple dating techniques

answers: NDQ_005719

answers: U–Pb dating

answers: NDQ_005720

answers: U–Pb dating

text: In 2009, Noble formed her own dating company, 'Kezia Noble Limited', which now employs over 15 trained male and female dating instructors for men.

text: In 2009, Noble formed her own dating company, 'Kezia Noble Limited', which now employs over 15 trained male and female dating instructors for men.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: argon is used to determine the age of a mineral.

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: 15

answers: NDQ_005712

answers: 15 trained male and female dating instructors for men.

answers: NDQ_005713

answers: 15 trained male and female dating instructors for men.

answers: NDQ_005714

answers: 15 trained male and female dating instructors for men.

answers: NDQ_005715

answers: 15

answers: NDQ_005716

answers: 15 trained male and female dating instructors for men.

answers: NDQ_005717

answers: 15 trained male and female dating instructors for men.

answers: NDQ_005718

answers: male and female dating instructors for men.

answers: NDQ_005719

answers: In 2009,

answers: NDQ_005720

answers: 15 trained male and female dating instructors for men.

text: Radiocarbon dating is carried out by measuring how much of the carbon-14 and nitrogen-14 isotopes are found in a material. The ratio between the two is used to estimate the material’s age. Suitable materials include wood, charcoal, paper, fabrics, fossils and shells. It is assumed that rock exists in layers according to age, with older beds below later ones. This is the basis of stratigraphy.

text: Radiocarbon dating is carried out by measuring how much of the carbon-14 and nitrogen-14 isotopes are found in a material. The ratio between the two is used to estimate the material’s age. Suitable materials include

text: wood

text: charcoal

text: paper

text: fabric

text: s,

text: fossil

text: s and

text: shell

text: s. It is assumed that rock exists in layers according to age, with older beds below later ones. This is the basis of

text: stratigraphy

answers: NDQ_005711

answers: Radiocarbon dating

answers: NDQ_005712

answers: carbon-14 and nitrogen-14

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: the ratio between the two isotopes

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 isotopes

answers: NDQ_005717

answers: the ratio between the two is used to estimate the material’s age

answers: NDQ_005718

answers: it is assumed that rock exists in layers

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: The ratio between the two

answers: NDQ_005712

answers: wood, charcoal, paper, fabrics, fossils and shells.

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: The ratio between the two is used to estimate the material’s age.

answers: NDQ_005715

answers: Radiocarbon dating

answers: NDQ_005716

answers: how much of the carbon-14 and nitrogen-14 isotopes

answers: NDQ_005717

answers: The ratio between the two is used to estimate the material’s age.

answers: NDQ_005718

answers: age.

answers: NDQ_005719

answers: Radiocarbon

answers: NDQ_005720

answers: Radiocarbon dating

text: Lined hearths are easily identified by the presence of fire-cracked rock, often created when the heat from the fires inside the hearths chemically altered and cracked the stone.  Often present are fragmented fish and animal bones, carbonized shell, charcoal, ash, and other waste products, all embedded in a sequence of soil that has been deposited atop the hearth.  Unlined hearths, which are less easily identified, may also include these materials.  Because of the organic nature of most of these items, they can be used to pinpoint the date the hearth was last used via the process of radiocarbon dating.  Although carbon dates can be negatively affected if the users of the hearth burned old wood or coal, the process is typically quite reliable. This was the most common way to cook, and to heat interior spaces in cool seasons.

text: Lined hearths are easily identified by the presence of

text: fire-cracked rock

text: , often created when the heat from the fires inside the hearths chemically altered and cracked the stone.  Often present are fragmented

text: fish

text: and

text: animal

text: bones,

text: carbon

text: ized

text: shell

text: charcoal

text: , ash, and other waste products, all embedded in a

text: sequence

text: of

text: soil

text: that has been deposited atop the hearth.  Unlined hearths, which are less easily identified, may also include these materials.  Because of the

text: organic

text: nature of most of these items, they can be used to pinpoint the date the hearth was last used via the process of

text: radiocarbon dating

text: .  Although carbon dates can be negatively affected if the users of the hearth burned old wood or coal, the process is typically quite reliable. This was the most common way to cook, and to heat interior spaces in cool seasons.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Because of the organic nature of most of these items

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: unlined hearths, which are less likely to include these materials

answers: NDQ_005718

answers: can be negatively affected if the users of the hearth burned old wood or coal

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: organic nature

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: organic nature

answers: NDQ_005715

answers: radiocarbon dating.

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: if the users of the hearth burned old wood or coal,

answers: NDQ_005719

answers: radiocarbon dating.

answers: NDQ_005720

answers: radiocarbon dating.

text: Canada has a long history of involvement with nuclear research, dating back to the pioneering work of Ernest Rutherford at McGill University in 1899. In 1940, George Laurence of the National Research Council (NRC) began experiments in Ottawa to measure neutron capture and nuclear fission  in uranium to demonstrate the feasibility of a nuclear reactor. For the purpose, he obtained  of uranium dioxide in paper bags from the Eldorado Mine at Port Radium in the Northwest Territories. For a neutron moderator, he used carbon in the form of petroleum coke. This was placed with the bags of uranium oxide in a large wooden bin lined with paraffin wax, another neutron moderator. A neutron source was added, and a Geiger counter used to measure radioactivity.

text: Canada has a long history of involvement with nuclear research, dating back to the pioneering work of

text: Ernest Rutherford

text: at

text: McGill University

text: in 1899. In 1940,

text: George Laurence

text: of the

text: National Research Council

text: (NRC) began experiments in

text: Ottawa

text: to measure

text: neutron capture

text: and

text: nuclear fission

text: in

text: uranium

text: to demonstrate the feasibility of a

text: nuclear reactor

text: . For the purpose, he obtained  of

text: uranium dioxide

text: in paper bags from the

text: Eldorado Mine

text: at

text: Port Radium

text: in the

text: Northwest Territories

text: . For a

text: neutron moderator

text: , he used

text: carbon

text: in the form of

text: petroleum coke

text: . This was placed with the bags of uranium oxide in a large wooden bin lined with

text: paraffin wax

text: , another neutron moderator. A neutron source was added, and a

text: Geiger counter

text: used to measure radioactivity.

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: geiger counter

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: For a neutron moderator, he used carbon in the form of petroleum coke

answers: NDQ_005718

answers: neutron capture

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radioactivity.

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: neutron capture and nuclear fission in uranium

answers: NDQ_005714

answers: radioactivity.

answers: NDQ_005715

answers: uranium

answers: NDQ_005716

answers: carbon in the form of petroleum coke.

answers: NDQ_005717

answers: 1899.

answers: NDQ_005718

answers: neutron capture

answers: NDQ_005719

answers: uranium dioxide

answers: NDQ_005720

answers: uranium

text: Uranium-238 is an α emitter, decaying through the 18-member uranium series into lead-206. The decay series of uranium-235 (historically called actino-uranium) has 15 members that ends in lead-207. The constant rates of decay in these series makes comparison of the ratios of parent to daughter elements useful in radiometric dating. Uranium-233 is made from thorium-232 by neutron bombardment.

text: Uranium-238 is an

text: α

text: emitter, decaying through the 18-member

text: uranium series

text: into

text: . The

text: decay series of uranium-235

text: (historically called actino-uranium) has 15 members that ends in lead-207. The constant rates of decay in these series makes comparison of the ratios of parent to daughter elements useful in

text: radiometric dating

text: is made from

text: by

text: neutron

text: bombardment.

answers: NDQ_005711

answers: constant rates of decay

answers: NDQ_005712

answers: constant rates of decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: Uranium-238 is an  emitter

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: comparison of the ratios of parent to daughter elements

answers: NDQ_005718

answers: constant rates of decay

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: ratios of parent to daughter elements

answers: NDQ_005712

answers: The constant rates of decay

answers: NDQ_005713

answers: comparison of the ratios of parent to daughter elements useful in radiometric dating.

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: lead-206.

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: comparison of the ratios of parent to daughter elements useful in radiometric dating.

answers: NDQ_005718

answers: constant rates of decay

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: Age Limit: No upper age limit, but candidates' date of birth should not be after 01/07/2000 (For 1st year candidates).

text: Age Limit: No upper age limit, but candidates' date of birth should not be after 01/07/2000 (For 1st year candidates).

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: age limits are too low

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: 1/7/2000

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: can be used to determine the age of minerals

answers: NDQ_005718

answers: age limit

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005712

answers: Age Limit: No upper age limit,

answers: NDQ_005713

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005714

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005715

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005716

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005717

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005718

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005719

answers: candidates' date of birth should not be after 01/07/2000

answers: NDQ_005720

answers: candidates' date of birth should not be after 01/07/2000

text: Researchers use radioactive atoms to determine the age of materials that were once part of a living organism. The age of such materials can be estimated by measuring the amount of radioactive carbon they contain in a process called radiocarbon dating. Similarly, using other radioactive elements, the age of rocks and other geological features (even some man-made objects) can be determined; this is called Radiometric dating. Environmental scientists use radioactive atoms, known as tracer atoms, to identify the pathways taken by pollutants through the environment.

text: Researchers use radioactive atoms to determine the age of materials that were once part of a living organism. The age of such materials can be estimated by measuring the amount of radioactive carbon they contain in a process called

text: radiocarbon dating

text: . Similarly, using other radioactive elements, the age of rocks and other geological features (even some man-made objects) can be determined; this is called

text: Radiometric dating

text: . Environmental scientists use radioactive atoms, known as

text: tracer atoms

text: , to identify the pathways taken by pollutants through the environment.

answers: NDQ_005711

answers: using other radioactive elements

answers: NDQ_005712

answers: radioactive elements

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radioactive carbon

answers: NDQ_005715

answers: NDQ_005716

answers: radioactive atoms

answers: NDQ_005717

answers: The age of such materials can be estimated by measuring the amount of radioactive carbon they contain

answers: NDQ_005718

answers: man-made objects can be determined

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: measuring the amount of radioactive carbon they contain

answers: NDQ_005712

answers: materials that were once part of a living organism.

answers: NDQ_005713

answers: Radiometric dating.

answers: NDQ_005714

answers: to determine the age of materials that were once part of a living organism.

answers: NDQ_005715

answers: radiocarbon dating.

answers: NDQ_005716

answers: radiocarbon dating.

answers: NDQ_005717

answers: measuring the amount of radioactive carbon they contain

answers: NDQ_005718

answers: man-made objects)

answers: NDQ_005719

answers: radiocarbon dating.

answers: NDQ_005720

answers: radiocarbon dating.

text: The volcanics originated as oceanic crust and seamounts. Potassium argon dating gives an age of 50.7 ± 3.1 to 58.1 ± 1.5 Ma.

text: The volcanics originated as

text: oceanic crust

text: and

text: seamounts

text: Potassium argon dating

text: gives an age of 50.7 ± 3.1 to 58.1 ± 1.5 Ma.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: 50.7  3.1 to 58.1  1.5 Ma

answers: NDQ_005718

answers: Potassium argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Potassium argon

answers: NDQ_005712

answers: Potassium argon

answers: NDQ_005713

answers: Potassium argon

answers: NDQ_005714

answers: Potassium argon

answers: NDQ_005715

answers: Potassium argon

answers: NDQ_005716

answers: Potassium argon

answers: NDQ_005717

answers: 50.7 <unk> 3.1 to 58.1 <unk> 1.5 Ma.

answers: NDQ_005718

answers: Potassium argon

answers: NDQ_005719

answers: Potassium argon

answers: NDQ_005720

answers: 50.7 <unk> 3.1 to 58.1 <unk> 1.5 Ma.

text: Radiometric dating is the foundation by which many modern scientists date rocks in order to determine the age of the earth (among other things). Conventionally, the earth has been dated to be approximately 4.6 billion years old.

text: Radiometric dating is the foundation by which many modern scientists date rocks in order to determine the age of the earth (among other things). Conventionally, the earth has been dated to be approximately 4.6 billion years old.

answers: NDQ_005711

answers: yes

answers: NDQ_005712

answers: 4.6 billion years old

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiometric dating is the foundation

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dating is the foundation by which many modern scientists date rocks

answers: NDQ_005718

answers: the age of the earth

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: rocks

answers: NDQ_005712

answers: 4.6 billion years old.

answers: NDQ_005713

answers: Radiometric dating

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: Radiometric dating

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: 4.6 billion years old.

answers: NDQ_005718

answers: 4.6 billion years old.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: 4.6 billion years old.

text: Pb is entirely primordial, and is thus useful for estimating the fraction of the other lead isotopes in a given sample that are also primordial (since the relative fractions of the various primordial lead isotopes is constant everywhere). Any excess lead 206, 207, and 208 is thus assumed to be radiogenic in origin, allowing various uranium and thorium dating schemes to be used to estimate the age of rocks (time since their formation).

text: Pb is entirely

text: primordial

text: , and is thus useful for estimating the fraction of the other lead isotopes in a given sample that are also primordial (since the relative fractions of the various primordial lead isotopes is constant everywhere). Any excess lead 206, 207, and 208 is thus assumed to be

text: radiogenic

text: in origin, allowing various uranium and thorium dating schemes to be used to estimate the age of rocks (time since their formation).

answers: NDQ_005711

answers: time since their formation

answers: NDQ_005712

answers: thorium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: Pb is entirely primordial

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radiogenic in origin

answers: NDQ_005717

answers: lead isotopes in a given sample that are also primordial

answers: NDQ_005718

answers: time since their formation

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: (time since their formation).

answers: NDQ_005712

answers: Any excess lead 206, 207, and 208

answers: NDQ_005713

answers: uranium and thorium dating schemes

answers: NDQ_005714

answers: Pb is entirely primordial,

answers: NDQ_005715

answers: Pb is entirely primordial,

answers: NDQ_005716

answers: Pb is entirely primordial,

answers: NDQ_005717

answers: Any excess lead 206, 207, and 208

answers: NDQ_005718

answers: (time since their formation).

answers: NDQ_005719

answers: thorium dating schemes to be used to estimate the age of rocks

answers: NDQ_005720

answers: uranium and thorium dating schemes

text: The Fa Hien Cave in the Kalutara district in Sri Lanka, one of the largest caves on the island, has yielded some of the earliest such fossils. Radiometric dating from excavated charcoal samples indicated that the cave was occupied from 34,000 to 5,400 BP, a period that was found to be consistent with the occupational levels of some other caves on the island. Dates from cultural sequences at the cave suggested a slightly earlier settlement from 38,000 BP. The oldest skeletal remains unearthed from Fa Hien Cave were that of a child with an associated radiocarbon dating of 30,000 BP.

text: The

text: Fa Hien Cave

text: in the

text: Kalutara

text: district in Sri Lanka, one of the largest caves on the island, has yielded some of the earliest such fossils.

text: Radiometric dating

text: from excavated charcoal samples indicated that the cave was occupied from 34,000 to 5,400 BP, a period that was found to be consistent with the occupational levels of some other caves on the island. Dates from cultural sequences at the cave suggested a slightly earlier settlement from 38,000 BP. The oldest skeletal remains unearthed from Fa Hien Cave were that of a child with an associated radiocarbon dating of 30,000 BP.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: radiocarbon dating

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: excavated charcoal samples

answers: NDQ_005712

answers: 34,000 to 5,400 BP,

answers: NDQ_005713

answers: 30,000 BP.

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: 5,400 BP,

answers: NDQ_005716

answers: radiocarbon dating of 30,000 BP.

answers: NDQ_005717

answers: 30,000 BP.

answers: NDQ_005718

answers: consistent with the occupational levels of some other caves on the island.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: 34,000 to 5,400 BP,

text: Radiocarbon dating done in the United States yielded a date of AD 1020 to 1270, corroborating the C-14 date of AD 920 to 1160 derived by an Indian laboratory. With no associated artifacts that could have been used for comparative dating, the overlap in the radiocarbon dates, that is 1020 to 1160, should be regarded as the likely date of the vessel.

text: Radiocarbon dating

text: done in the United States yielded a date of AD 1020 to 1270, corroborating the C-14 date of AD 920 to 1160 derived by an Indian laboratory. With no associated artifacts that could have been used for comparative dating, the overlap in the radiocarbon dates, that is 1020 to 1160, should be regarded as the likely date of the vessel.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: no associated artifacts

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: C-14 date of AD 920 to 1160

answers: NDQ_005718

answers: no associated artifacts

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: Radiocarbon

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: comparative dating,

answers: NDQ_005715

answers: C-14 date of AD 920 to 1160

answers: NDQ_005716

answers: Radiocarbon dating

answers: NDQ_005717

answers: 920 to 1160

answers: NDQ_005718

answers: no associated artifacts that could have been used for comparative dating,

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: Louis also wrote "Finding the World's Earliest Man" for the September 1960 issue of National Geographic, estimating the fossil's age to be 600,000 years old.  University of California, Berkeley, geochemists Garniss Curtis and Jack Evernden used potassium-argon dating to re-assess the site, finding that Olduvai's Bed I was actually about .  Such an application of geochronology was unprecedented; OH 5 became the first hominin to be dated by that method.  The same process was used for OH 7, the holotype of Homo habilis (handy man).

text: Louis also wrote "Finding the World's Earliest Man" for the September 1960 issue of National Geographic, estimating the fossil's age to be 600,000 years old.  University of California, Berkeley,

text: geochemists

text: Garniss Curtis and Jack Evernden used

text: potassium-argon dating

text: to re-assess the site, finding that Olduvai's Bed I was actually about .  Such an application of

text: geochronology

text: was unprecedented; OH 5 became the first

text: hominin

text: to be dated by that method.  The same process was used for

text: OH 7

text: , the holotype of

text: Homo habilis

text: (handy man).

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: potassium-argon dating

answers: NDQ_005717

answers: OH 5 became the first hominin to be dated by that method

answers: NDQ_005718

answers: potassium-argon dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 600,000 years old.

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: geochronology

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: geochronology

answers: NDQ_005717

answers: to re-assess the site,

answers: NDQ_005718

answers: 600,000 years old.

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: potassium-argon

text: Paleontology seeks to map out how life evolved across geologic time. A substantial hurdle is the difficulty of working out fossil ages. Beds that preserve fossils typically lack the radioactive elements needed for radiometric dating. This technique is our only means of giving rocks greater than about 50 million years old an absolute age, and can be accurate to within 0.5% or better. Although radiometric dating requires careful laboratory work, its basic principle is simple: the rates at which various radioactive elements decay are known, and so the ratio of the radioactive element to its decay products shows how long ago the radioactive element was incorporated into the rock. Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are volcanic ash layers, which may provide termini for the intervening sediments.

text: Paleontology seeks to map out how life evolved across geologic time. A substantial hurdle is the difficulty of working out fossil ages. Beds that preserve fossils typically lack the radioactive elements needed for

text: radiometric dating

text: . This technique is our only means of giving rocks greater than about 50 million years old an absolute age, and can be accurate to within 0.5% or better. Although radiometric dating requires careful laboratory work, its basic principle is simple: the rates at which various radioactive elements

text: decay

text: are known, and so the ratio of the radioactive element to its decay products shows how long ago the radioactive element was incorporated into the rock. Radioactive elements are common only in rocks with a volcanic origin, and so the only fossil-bearing rocks that can be dated radiometrically are volcanic ash layers, which may provide termini for the intervening sediments.

answers: NDQ_005711

answers: rates at which various radioactive elements decay

answers: NDQ_005712

answers: rocks with a volcanic origin

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radioactive elements are common only in rocks with a volcanic origin

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: radioactive elements decay

answers: NDQ_005717

answers: can be accurate to within 0.5% or better

answers: NDQ_005718

answers: lack the radioactive elements needed for radiometric dating

answers: NDQ_005719

answers: NDQ_005720

answers: radiometric dating

answers: NDQ_005711

answers: the rates at which various radioactive elements decay are known,

answers: NDQ_005712

answers: Radioactive elements are common only in rocks with a volcanic origin,

answers: NDQ_005713

answers: the rates at which various radioactive elements decay are known,

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radioactive elements

answers: NDQ_005717

answers: the ratio of the radioactive element to its decay products

answers: NDQ_005718

answers: difficulty of working out fossil ages.

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: There is one Marine Optical Buoy operating in the water, and another in maintenance on shore. Every 3 to 4 months, a team exchanges the two buoys. The team calibrates each MOBY while it is in maintenance, both before deploying the buoy and after recovering it. Additionally, a team visits the MOBY in the water monthly, to clean algae, barnacles, and other organisms off the light collectors; and to generate independent comparison data using portable reference light sources. Each MOBY has internal reference light sources, as well, for continuous but not independent comparison. The MOBY calibration data traces to National Institute of Standards and Technology (NIST) radiometric standards directly, as opposed to using intermediate standards.

text: There is one Marine Optical Buoy operating in the water, and another in maintenance on shore. Every 3 to 4 months, a team exchanges the two buoys. The team calibrates each MOBY while it is in maintenance, both before deploying the buoy and after recovering it. Additionally, a team visits the MOBY in the water monthly, to clean algae, barnacles, and other organisms off the light collectors; and to generate independent comparison data using portable reference light sources. Each MOBY has internal reference light sources, as well, for continuous but not independent comparison. The MOBY

text: calibration

text: data

text: traces

text: to

entity_name: National Institute of Standards and Technology

text: National Institute of Standards and Technology

text: (NIST)

text: radiometric

text: standards directly, as opposed to using intermediate standards.

answers: NDQ_005711

answers: radiometric standards

answers: NDQ_005712

answers: MOBY calibration data

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: MoBY calibration data

answers: NDQ_005717

answers: The MOBY calibration data

answers: NDQ_005718

answers: not independent comparison

answers: NDQ_005719

answers: are useful for very young materials

answers: NDQ_005720

answers: NDQ_005711

answers: National Institute of Standards and Technology (NIST) radiometric standards directly,

answers: NDQ_005712

answers: intermediate standards.

answers: NDQ_005713

answers: National Institute of Standards and Technology (NIST) radiometric standards

answers: NDQ_005714

answers: intermediate standards.

answers: NDQ_005715

answers: (NIST) radiometric standards

answers: NDQ_005716

answers: intermediate standards.

answers: NDQ_005717

answers: intermediate standards.

answers: NDQ_005718

answers: intermediate standards.

answers: NDQ_005719

answers: (NIST) radiometric standards directly, as opposed to using intermediate standards.

answers: NDQ_005720

answers: (NIST) radiometric standards

text: Proponents of the Bimini Road being a manmade feature argue that these radiocarbon dates are invalid because they were obtained entirely from whole-rock samples and subject to contamination from younger carbon. The background data reported by Calvert and others concerning the radiocarbon dates from the Bimini Road demonstrate that not all of these dates come entirely from whole-rock samples. That the dates from the shells and the clearly younger cement holding them together as beachrock are temporally consistent argues against any signification alteration of their radiocarbon content. In addition, other studies using radiocarbon dating to study sea level and the age of sediment and beachrock within the Bahamas have not reported any significant problems with contamination by younger radiocarbon. In their detailed research, Davaud and Strasser accepted the radiocarbon dates obtained from the beachrock composing the Bimini Road from the radiocarbon laboratory at the University of Miami as valid indicators of its age.

text: Proponents of the Bimini Road being a manmade feature argue that these radiocarbon dates are invalid because they were obtained entirely from whole-rock samples and subject to contamination from younger carbon. The background data reported by Calvert and others concerning the radiocarbon dates from the Bimini Road demonstrate that not all of these dates come entirely from whole-rock samples. That the dates from the shells and the clearly younger cement holding them together as beachrock are temporally consistent argues against any signification alteration of their radiocarbon content. In addition, other studies using radiocarbon dating to study sea level and the age of sediment and beachrock within the Bahamas have not reported any significant problems with contamination by younger radiocarbon. In their detailed research, Davaud and Strasser accepted the radiocarbon dates obtained from the beachrock composing the Bimini Road from the radiocarbon laboratory at the University of Miami as valid indicators of its age.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: contamination from younger carbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: contamination from younger carbon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon content.

answers: NDQ_005712

answers: younger cement holding them together as beachrock are temporally consistent

answers: NDQ_005713

answers: radiocarbon dates are invalid because they were obtained entirely from whole-rock samples

answers: NDQ_005714

answers: whole-rock samples and subject to contamination from younger carbon.

answers: NDQ_005715

answers: radiocarbon dates from the Bimini Road

answers: NDQ_005716

answers: carbon.

answers: NDQ_005717

answers: not reported any significant problems with contamination by younger radiocarbon.

answers: NDQ_005718

answers: contamination from younger carbon.

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dates are invalid because they were obtained entirely from whole-rock samples

text: Radiocarbon dating is generally limited to dating samples no more than 50,000 years old, as samples older than that have insufficient  to be measurable.  Older dates have been obtained by using special sample preparation techniques, large samples, and very long measurement times.  These techniques can allow measurement of dates up to 60,000 and in some cases up to 75,000 years before the present.

text: Radiocarbon dating is generally limited to dating samples no more than 50,000 years old, as samples older than that have insufficient  to be measurable.  Older dates have been obtained by using special sample preparation techniques, large samples, and very long measurement times.  These techniques can allow measurement of dates up to 60,000 and in some cases up to 75,000 years before the present.

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: samples older than that have insufficient to be measurable

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: samples older than that have insufficient to be measurable

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: 60,000 and in some cases up to 75,000 years before the present

answers: NDQ_005718

answers: dating samples no more than 50,000 years old

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Radiocarbon

answers: NDQ_005712

answers: samples older than that have insufficient to be measurable.

answers: NDQ_005713

answers: Radiocarbon

answers: NDQ_005714

answers: samples older than that have insufficient to be measurable.

answers: NDQ_005715

answers: 50,000

answers: NDQ_005716

answers: samples older than that have insufficient to be measurable.

answers: NDQ_005717

answers: 60,000 and in some cases up to 75,000 years before the present.

answers: NDQ_005718

answers: dating samples no more than 50,000 years old,

answers: NDQ_005719

answers: 50,000 years old,

answers: NDQ_005720

answers: 60,000

text: The oldest activity occurred between 1,000,000 and 750,000 years ago, forming lava domes. A gap of about 500,000 years separates Ciomadul from the activity of other volcanoes in the area. The two oldest dates of 1,020,000 and 850,000 years ago were obtained on peripheral lava domes. Activity reached a peak between  650,000 - 500,000 years ago, when the principal lava domes were formed. This effusive phase is also known as "old Ciomadul". Other dating techniques indicate a start of activity less than 250,000 years ago. The youngest lava dome was dated at 42,900 ± 1,500 years ago by uranium-thorium dating, much younger than the dates obtained by potassium-argon dating. There is in fact substantial disagreement between dates obtained by potassium-argon dating and uranium-thorium dating at Ciomadul. These dates indicate a construction of the central lava domes between 590,000 and 140,000 years ago.

text: The oldest activity occurred between 1,000,000 and 750,000 years ago, forming

text: lava dome

text: s. A gap of about 500,000 years separates Ciomadul from the activity of other volcanoes in the area. The two oldest dates of 1,020,000 and 850,000 years ago were obtained on peripheral lava domes. Activity reached a peak between  650,000 - 500,000 years ago, when the principal

text: lava dome

text: s were formed. This

text: effusive

text: phase is also known as "old Ciomadul". Other dating techniques indicate a start of activity less than 250,000 years ago. The youngest lava dome was dated at 42,900 ± 1,500 years ago by

text: uranium-thorium dating

text: , much younger than the dates obtained by

text: potassium-argon dating

text: . There is in fact substantial disagreement between dates obtained by

text: potassium-argon dating

text: and

text: uranium-thorium dating

text: at Ciomadul. These dates indicate a construction of the central lava domes between 590,000 and 140,000 years ago.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: NDQ_005716

answers: potassium-argon dating

answers: NDQ_005717

answers: much younger than the dates obtained by potassium-argon dating

answers: NDQ_005718

answers: substantial disagreement between dates obtained by potassium-argon dating and uranium-thorium dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-thorium dating,

answers: NDQ_005712

answers: peripheral lava domes.

answers: NDQ_005713

answers: uranium-thorium dating,

answers: NDQ_005714

answers: uranium-thorium dating,

answers: NDQ_005715

answers: uranium-thorium dating,

answers: NDQ_005716

answers: uranium-thorium dating,

answers: NDQ_005717

answers: There is in fact substantial disagreement

answers: NDQ_005718

answers: substantial disagreement

answers: NDQ_005719

answers: uranium-thorium dating,

answers: NDQ_005720

answers: uranium-thorium dating,

text: Subsequent radiometric dating reduced the uncertainty. The concentration of  decay products in impact glasses from the crater were used to derive an age of 65.04 ± 1.10 million years. Analysis of argon radioactive decay products yielded an age of 65.17 ± 0.64 million years. These ages are similar to that of Chicxulub Crater. An August 2010 study of ancient fern spikes suggests the Boltysh impact likely occurred several thousand years before Chicxulub.

text: Subsequent

text: radiometric dating

text: reduced the uncertainty. The concentration of  decay products in impact glasses from the crater were used to derive an age of 65.04 ± 1.10 million years. Analysis of

text: argon

text: radioactive decay products yielded an age of 65.17 ± 0.64 million years. These ages are similar to that of Chicxulub Crater. An August 2010 study of ancient

text: fern

text: spikes suggests the Boltysh impact likely occurred several thousand years before Chicxulub.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay products

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radioactive decay products yield an age

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: 65.17  0.64 million years

answers: NDQ_005718

answers: uncertainty

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: The concentration of decay products

answers: NDQ_005712

answers: similar to that of Chicxulub Crater.

answers: NDQ_005713

answers: 65.04 <unk> 1.10 million years.

answers: NDQ_005714

answers: radiometric dating reduced the uncertainty.

answers: NDQ_005715

answers: 65.04 <unk> 1.10 million years.

answers: NDQ_005716

answers: decay products

answers: NDQ_005717

answers: 65.17 <unk> 0.64 million years.

answers: NDQ_005718

answers: uncertainty.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: 65.04 <unk> 1.10 million years.

text: Actinium is found only in traces in uranium ores – one tonne of uranium in ore contains about 0.2 milligrams of Ac – and in thorium ores, which contain about 5 nanograms of Ac per one tonne of thorium. The actinium isotope Ac is a transient member of the uranium-actinium series decay chain, which begins with the parent isotope U (or Pu) and ends with the stable lead isotope Pb. The isotope Ac is a transient member of the thorium series decay chain, which begins with the parent isotope Th and ends with the stable lead isotope Pb. Another actinium isotope (Ac) was transiently present in the neptunium series decay chain, beginning with Np (or U) and ending with thallium (Tl) and near-stable bismuth (Bi), but this chain existed only in the early Solar System, due to the short half-life of neptunium-237.

text: Actinium is found only in traces in

text: uranium

text: ores – one tonne of uranium in ore contains about 0.2 milligrams of Ac – and in

text: thorium

text: ores, which contain about 5 nanograms of Ac per one tonne of thorium. The actinium

text: isotope

text: Ac is a transient member of the

text: uranium-actinium series

text: decay chain

text: , which begins with the parent isotope

text: U

text: (or

text: Pu

text: ) and ends with the stable lead isotope

text: Pb

text: . The isotope Ac is a transient member of the

text: thorium series

text: decay chain, which begins with the parent isotope

text: Th

text: and ends with the stable lead isotope

text: Pb

text: . Another actinium isotope (Ac) was transiently present in the

text: neptunium series

text: decay chain

text: , beginning with

text: Np

text: (or

text: U)

text: and ending with

text: thallium

text: (Tl) and near-stable

text: bismuth

text: (Bi), but this chain existed only in the early

text: Solar System

text: , due to the short half-life of neptunium-237.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: neptunium-237

answers: NDQ_005713

answers: NDQ_005714

answers: half-life of neptunium-237

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: actinium decay

answers: NDQ_005717

answers: traces in uranium ores

answers: NDQ_005718

answers: short half-life of neptunium-237

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: uranium-actinium series decay chain,

answers: NDQ_005712

answers: early Solar System,

answers: NDQ_005713

answers: uranium-actinium series decay chain,

answers: NDQ_005714

answers: Actinium

answers: NDQ_005715

answers: neptunium-237.

answers: NDQ_005716

answers: Actinium

answers: NDQ_005717

answers: Actinium

answers: NDQ_005718

answers: short half-life

answers: NDQ_005719

answers: Actinium

answers: NDQ_005720

answers: Actinium

text: In archaeology, seriation is a relative dating method in which assemblages or artifacts from numerous sites, in the same culture, are placed in chronological order. Where absolute dating methods, such as carbon dating, cannot be applied, archaeologists have to use relative dating methods to date archaeological finds and features. Seriation is a standard method of dating in archaeology.  It can be used to date stone tools, pottery fragments, and other artifacts. In Europe, it has been used frequently to reconstruct the  chronological sequence of graves in a cemetery (e.g. Jørgensen 1992;  Müssemeier, Nieveler et al. 2003).

text: In

text: archaeology

text: , seriation is a

text: relative dating

text: method in which

text: assemblages

text: or

text: artifacts

text: from numerous sites, in the same culture, are placed in chronological order. Where

text: absolute dating

text: methods, such as

text: carbon dating

text: , cannot be applied, archaeologists have to use

text: relative dating

text: methods to date archaeological finds and features. Seriation is a standard method of dating in archaeology.  It can be used to date stone tools, pottery fragments, and other artifacts. In Europe, it has been used frequently to reconstruct the  chronological sequence of graves in a cemetery (e.g. Jørgensen 1992;  Müssemeier, Nieveler et al. 2003).

answers: NDQ_005711

answers: carbon

answers: NDQ_005712

answers: carbon dating cannot be applied

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: absolute dating methods

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: absolute dating methods

answers: NDQ_005717

answers: Seriation is a standard method

answers: NDQ_005718

answers: absolute dating methods

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: carbon

answers: NDQ_005712

answers: carbon dating,

answers: NDQ_005713

answers: carbon dating,

answers: NDQ_005714

answers: absolute dating methods, such as carbon dating, cannot be applied,

answers: NDQ_005715

answers: carbon dating,

answers: NDQ_005716

answers: absolute dating

answers: NDQ_005717

answers: placed in chronological order.

answers: NDQ_005718

answers: absolute dating methods, such as carbon dating, cannot be applied,

answers: NDQ_005719

answers: carbon dating,

answers: NDQ_005720

answers: carbon dating,

text: Another, better known, date notation that is used for similar purposes is the Julian date. Universal time, or closely related time scales, are always used with the Julian date, the day begins at noon, and a decimal fraction may be used to represent the time of day. In contrast, Ohms did not make any mention of time zones or time of day in his paper; the Lilian date is a pure date format. If time is reckoned in Universal Time, and the Lilian date is taken to begin at midnight, the Lilian date can be obtained from the Julian date by subtracting  from the Julian date and ignoring the decimal fraction in the result.

text: Another, better known, date notation that is used for similar purposes is the

text: Julian date

text: Universal time

text: , or closely related time scales, are always used with the Julian date, the day begins at noon, and a decimal fraction may be used to represent the time of day. In contrast, Ohms did not make any mention of time zones or time of day in his paper; the Lilian date is a pure date format. If time is reckoned in Universal Time, and the Lilian date is taken to begin at midnight, the Lilian date can be obtained from the Julian date by subtracting  from the Julian date and ignoring the decimal fraction in the result.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: radiometric dating

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Julian date is a pure date format

answers: NDQ_005718

answers: Ohms did not make any mention of time zones

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: date notation that is used for similar purposes is the Julian date.

answers: NDQ_005712

answers: Universal time, or closely related time scales,

answers: NDQ_005713

answers: Julian date.

answers: NDQ_005714

answers: Julian date.

answers: NDQ_005715

answers: Julian date.

answers: NDQ_005716

answers: Julian date.

answers: NDQ_005717

answers: the Lilian date

answers: NDQ_005718

answers: Ohms did not make any mention of time zones or time of day

answers: NDQ_005719

answers: Julian date.

answers: NDQ_005720

answers: Julian date.

text: Bigo, also Bigo bya Mugenyi, is an extensive alignment of ditches and berms comprising ancient earthworks located in the interlacustrine region of southwestern of Uganda, Africa. Situated on the southern shore of the Katonga River, Bigo is best described as having two elements. The first consists of a long, irregular ditch and bank alignment with multiple openings that effectively creates an outer boundary by connecting to the Kotanga River in the east and the Kakinga swamp to the west. Toward its eastern end the outer ditch branches further to the east to encompass a nearby crossing of the Katonga River. The second element consists of a central, interconnected group of four irregularly shaped ditch and bank enclosures that are connected to the Katonga River by a single ditch. Three mounds are associated with the central enclosures; two within and one immediately to the west. When combined, the Bigo earthworks extend for more than 10 kilometers. Resulting from radiometric dates collected from archaeological investigations conducted in 1960 and additional investigations undertaken at the Mansa earthworks site in 1988, 1994, and 1995, the Bigo earthworks have been dated to roughly AD 1300-1500, and have been called Uganda's "largest and most important ancient monument."

text: Bigo, also Bigo bya Mugenyi, is an extensive alignment of ditches and berms comprising ancient

text: earthworks

text: located in the

text: interlacustrine

text: region of southwestern of

text: Uganda

text: Africa

text: . Situated on the southern shore of the

text: Katonga River

text: , Bigo is best described as having two elements. The first consists of a long, irregular ditch and bank alignment with multiple openings that effectively creates an outer boundary by connecting to the Kotanga River in the east and the Kakinga

text: swamp

text: to the west. Toward its eastern end the outer ditch branches further to the east to encompass a nearby crossing of the Katonga River. The second element consists of a central, interconnected group of four irregularly shaped ditch and bank enclosures that are connected to the Katonga River by a single ditch. Three mounds are associated with the central enclosures; two within and one immediately to the west. When combined, the Bigo earthworks extend for more than 10 kilometers. Resulting from

text: radiometric

text: dates collected from

text: archaeological

text: investigations conducted in 1960 and additional investigations undertaken at the Mansa earthworks site in 1988, 1994, and 1995, the Bigo earthworks have been dated to roughly

text: AD

text: 1300-1500, and have been called Uganda's "largest and most important ancient monument."

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: AD 1300-1500

answers: NDQ_005713

answers: It's impossible to say

answers: NDQ_005714

answers: radiometric

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiometric dates

answers: NDQ_005717

answers: the Bigo earthworks have been dated to roughly AD 1300-1500

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: None of the above choices

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: archaeological investigations

answers: NDQ_005712

answers: AD 1300-1500,

answers: NDQ_005713

answers: AD 1300-1500,

answers: NDQ_005714

answers: radiometric dates

answers: NDQ_005715

answers: Bigo earthworks have been dated to roughly AD 1300-1500,

answers: NDQ_005716

answers: radiometric dates

answers: NDQ_005717

answers: Bigo earthworks have been dated to roughly AD 1300-1500,

answers: NDQ_005718

answers: dated to roughly AD 1300-1500,

answers: NDQ_005719

answers: AD 1300-1500,

answers: NDQ_005720

answers: Bigo earthworks have been dated to roughly AD 1300-1500,

text: Australopithecus bahrelghazali was dated by beryllium-based radiometric dating as living about 3.6 million years ago.

text: Australopithecus bahrelghazali was dated by

text: beryllium

text: -based

text: radiometric dating

text: as living about 3.6 million years ago.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: beryllium is radioactive

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a non-radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: beryllium-based dating

answers: NDQ_005718

answers: it cannot be used to determine the age of living organisms

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: beryllium-based

answers: NDQ_005712

answers: 3.6 million years ago.

answers: NDQ_005713

answers: beryllium-based

answers: NDQ_005714

answers: beryllium-based radiometric dating

answers: NDQ_005715

answers: 3.6

answers: NDQ_005716

answers: beryllium-based

answers: NDQ_005717

answers: 3.6 million years ago.

answers: NDQ_005718

answers: 3.6 million years ago.

answers: NDQ_005719

answers: beryllium-based radiometric dating

answers: NDQ_005720

answers: beryllium-based radiometric dating

text: The northern young lava flow is less than one million years old based on potassium-argon dating, the southern flow is 48,000 ± 12,000 years old based on argon-argon dating on biotite.

text: The northern young lava flow is less than one million years old based on potassium-argon dating, the southern flow is 48,000 ± 12,000 years old based on argon-argon dating on biotite.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: less than one million years old

answers: NDQ_005718

answers: less than one million years old

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: argon-argon dating on biotite.

answers: NDQ_005713

answers: argon-argon dating on biotite.

answers: NDQ_005714

answers: argon-argon

answers: NDQ_005715

answers: argon-argon

answers: NDQ_005716

answers: argon-argon

answers: NDQ_005717

answers: The northern young lava flow is less than one million years old

answers: NDQ_005718

answers: less than one million years old

answers: NDQ_005719

answers: potassium-argon

answers: NDQ_005720

answers: argon-argon dating on biotite.

text: However of the artifacts uncovered from the area of the bathhouse and dated by historians, or by using radiocarbon dating, none are known to predate the 2nd century AD. All artifacts are either Byzantine design (7th and 8th century AD). Some construction, although not radiocarbon dated, may extend as far back as the late Roman Era (2nd and 3rd century AD).

text: However of the artifacts uncovered from the area of the bathhouse and dated by historians, or by using radiocarbon dating, none are known to predate the 2nd century AD. All artifacts are either Byzantine design (7th and 8th century AD). Some construction, although not radiocarbon dated, may extend as far back as the late Roman Era (2nd and 3rd century AD).

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Byzantine design

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: none are known to predate the 2nd century AD

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: Byzantine design (7th and 8th century AD).

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating, none are known to predate the 2nd century AD.

answers: NDQ_005715

answers: radiocarbon dating, none are known to predate the 2nd century AD.

answers: NDQ_005716

answers: radiocarbon dating,

answers: NDQ_005717

answers: none are known to predate the 2nd century AD.

answers: NDQ_005718

answers: none are known to predate the 2nd century AD.

answers: NDQ_005719

answers: radiocarbon dating, none are known to predate the 2nd century AD.

answers: NDQ_005720

answers: radiocarbon dating, none are known to predate the 2nd century AD.

text: The age of the engravings has proven difficult to determine. Radiometric dating has produced a range of estimates, dating various carvings to between 300 and 3000 years of age.

text: The age of the engravings has proven difficult to determine.

text: Radiometric dating

text: has produced a range of estimates, dating various carvings to between 300 and 3000 years of age.

answers: NDQ_005711

answers: yes

answers: NDQ_005712

answers: radiometric dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric

answers: NDQ_005718

answers: the age of the engravings

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: between 300 and 3000 years of age.

answers: NDQ_005712

answers: between 300 and 3000 years of age.

answers: NDQ_005713

answers: 300 and 3000 years of age.

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: Radiometric dating

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: between 300 and 3000 years of age.

answers: NDQ_005718

answers: The age of the engravings has proven difficult to determine.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: Fourteen core samples of up to 125,000 years of age were collected off of Muir Seamount, ranging in depth to more than . These samples were used to analyse the weight percentage of carbonate over time on the ocean floor, which in turn would provide clues to the oceanic environment over time. Overall concentrations were most stable at  of depth. This was interpreted as indicating an increase in flow form colder waters of Antarctic flow, and the stagnation of the North American flows. A total of 8 core samples have been gathered, with ages ranging from Pliocene to Late Cretaceous. No radiometric dates are available for the seamount, but it may of Early Cretaceous time.

text: Fourteen

text: core sample

text: s of up to 125,000 years of age were collected off of Muir Seamount, ranging in depth to more than . These samples were used to analyse the weight percentage of

text: carbonate

text: over time on the ocean floor, which in turn would provide clues to the oceanic environment over time. Overall concentrations were most stable at  of depth. This was interpreted as indicating an increase in flow form colder waters of

text: Antarctic

text: flow, and the stagnation of the North American flows. A total of 8 core samples have been gathered, with ages ranging from

text: Pliocene

text: to

text: Late Cretaceous

text: . No radiometric dates are available for the seamount, but it may of

text: Early Cretaceous

text: time.

answers: NDQ_005711

answers: radiometric dating

answers: NDQ_005712

answers: it may of Early Cretaceous time

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbonate over time on the ocean floor

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: radiometric dates

answers: NDQ_005718

answers: No radiometric dates are available for the seamount

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: weight percentage of carbonate over time on the ocean floor,

answers: NDQ_005712

answers: Pliocene to Late Cretaceous.

answers: NDQ_005713

answers: Pliocene to Late Cretaceous.

answers: NDQ_005714

answers: provide clues to the oceanic environment over time.

answers: NDQ_005715

answers: Pliocene to Late Cretaceous.

answers: NDQ_005716

answers: carbonate

answers: NDQ_005717

answers: No radiometric dates

answers: NDQ_005718

answers: No radiometric dates are available for the seamount,

answers: NDQ_005719

answers: Pliocene to Late Cretaceous.

answers: NDQ_005720

answers: Pliocene to Late Cretaceous.

text: One of its great advantages is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a half-life of about 700 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample even if some of the lead has been lost. This can be seen in the concordia diagram, where the samples plot along an errorchron (straight line) which intersects the concordia curve at the age of the sample.

text: One of its great advantages is that any sample provides two clocks, one based on uranium-235's decay to lead-207 with a half-life of about 700 million years, and one based on uranium-238's decay to lead-206 with a half-life of about 4.5 billion years, providing a built-in crosscheck that allows accurate determination of the age of the sample even if some of the lead has been lost. This can be seen in the concordia diagram, where the samples plot along an errorchron (straight line) which intersects the concordia curve at the age of the sample.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium-235's decay

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: uranium-235's decay to lead-207

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: lead decay

answers: NDQ_005717

answers: uranium-235's decay to lead-207

answers: NDQ_005718

answers: some of the lead has been lost

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium-235's decay to lead-207

answers: NDQ_005712

answers: even if some of the lead has been lost.

answers: NDQ_005713

answers: any sample provides two clocks,

answers: NDQ_005714

answers: any sample provides two clocks,

answers: NDQ_005715

answers: 700 million years,

answers: NDQ_005716

answers: lead has been lost.

answers: NDQ_005717

answers: any sample provides two clocks,

answers: NDQ_005718

answers: some of the lead has been lost.

answers: NDQ_005719

answers: 4.5 billion years,

answers: NDQ_005720

answers: 4.5 billion years,

text: Originally, Berowra Waters Inn was a guest house dating to the 1930s CE. In 1975, the Inn was purchased by Tony and Gay Bilson. The Edwardian style teahouse had major engineering flaws however and a decision was made to close and redesign the venue. Between 1976 and 1983, the architect Glenn Murcutt redesigned the property using a 'distinctive Australian vernacular style: corrugated tin roof over glass louvre windows, on a Sydney sandstone base, set among eucalypts and angophoras". During excavating work for the rebuild, Indigenous Australian (Aboriginal) midden remains on the property boundary were discovered. These were radiocarbon dated and found to date back nearly 10,000 years, indicating a long term human association with the location.

text: Originally, Berowra Waters Inn was a guest house dating to the 1930s CE. In 1975, the Inn was purchased by

text: Tony

text: and

text: Gay Bilson

text: . The Edwardian style teahouse had major engineering flaws however and a decision was made to close and redesign the venue. Between 1976 and 1983, the architect

text: Glenn Murcutt

text: redesigned the property using a 'distinctive Australian vernacular style: corrugated tin roof over glass louvre windows, on a Sydney sandstone base, set among eucalypts and angophoras". During excavating work for the rebuild,

text: Indigenous Australian

text: (Aboriginal)

text: midden

text: remains on the property boundary were discovered. These were

text: radiocarbon

text: dated and found to date back nearly 10,000 years, indicating a long term human association with the location.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon dated

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: How long does carbon-14 decay?

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon dated

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon dated and found to date back nearly 10,000 years,

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: indicating a long term human association with the location.

answers: NDQ_005715

answers: 10,000 years,

answers: NDQ_005716

answers: radiocarbon dated and found to date back nearly 10,000 years,

answers: NDQ_005717

answers: radiocarbon dated and found to date back nearly 10,000 years,

answers: NDQ_005718

answers: radiocarbon

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dated

text: Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon (), a radioactive isotope of carbon.

text: Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing

text: organic material

text: by using the properties of

text: radiocarbon

text: (), a radioactive

text: isotope

text: of

text: carbon

answers: NDQ_005711

answers: using the properties

answers: NDQ_005712

answers: radioactive isotope

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive isotope

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon decay

answers: NDQ_005717

answers: radioactive isotopes

answers: NDQ_005718

answers: radioactive isotope

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: using the properties of radiocarbon

answers: NDQ_005712

answers: organic material by using the properties of radiocarbon

answers: NDQ_005713

answers: Radiocarbon dating

answers: NDQ_005714

answers: the properties of radiocarbon

answers: NDQ_005715

answers: Radiocarbon dating

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: determining the age of an object containing organic material

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: The discovery of all of the fossils at AL 333 aligned close together in one geological stratum is an obvious sign that they died at about the same time.  But absolute dating had to be used to ascertain that time.  Because the specimens were found between two layers of volcanic ash, potassium-argon dating was used.  Potassium-argon dating measures the ratio of radioactive potassium and the argon it decays into.  It is ideal for dating volcanic material.  In the case of AL 333, this method yielded an age of 3.18-3.21 million years.

text: The discovery of all of the fossils at AL 333 aligned close together in one geological stratum is an obvious sign that they died at about the same time.  But absolute dating had to be used to ascertain that time.  Because the specimens were found between two layers of volcanic ash,

text: potassium-argon dating

text: was used.  Potassium-argon dating measures the ratio of radioactive potassium and the argon it decays into.  It is ideal for dating volcanic material.  In the case of AL 333, this method yielded an age of 3.18-3.21 million years.

answers: NDQ_005711

answers: no

answers: NDQ_005712

answers: It is ideal for dating volcanic material

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: no

answers: NDQ_005715

answers: NDQ_005716

answers: absolute dating

answers: NDQ_005717

answers: the ratio of radioactive potassium and the argon it decays into

answers: NDQ_005718

answers: absolute dating

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: ratio of radioactive potassium and the argon it decays into.

answers: NDQ_005712

answers: volcanic material.

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: absolute dating

answers: NDQ_005717

answers: the ratio of radioactive potassium and the argon it decays into.

answers: NDQ_005718

answers: absolute dating

answers: NDQ_005719

answers: potassium-argon dating

answers: NDQ_005720

answers: potassium-argon dating

text: Estimated dates of initial settlement of Easter Island have ranged from 300 to 1200 CE, approximately coinciding with the arrival of the first settlers in Hawaii. Rectifications in radiocarbon dating have changed almost all of the previously posited early settlement dates in Polynesia. Rapa Nui is now considered to have been settled in the narrower range of 700 to 1100 CE. Ongoing archaeological studies suggest a still-later date: "Radiocarbon dates for the earliest stratigraphic layers at Anakena, Easter Island, and analysis of previous radiocarbon dates imply that the island was colonized late, about 1200 CE. Significant ecological impacts and major cultural investments in monumental architecture and statuary thus began soon after initial settlement."

text: Estimated dates of initial settlement of Easter Island have ranged from 300 to 1200

text: CE

text: , approximately coinciding with the arrival of the first settlers in Hawaii. Rectifications in

text: radiocarbon dating

text: have changed almost all of the previously posited early settlement dates in Polynesia. Rapa Nui is now considered to have been settled in the narrower range of 700 to 1100 CE. Ongoing archaeological studies suggest a still-later date: "Radiocarbon dates for the earliest stratigraphic layers at Anakena, Easter Island, and analysis of previous radiocarbon dates imply that the island was colonized late, about 1200 CE. Significant ecological impacts and major cultural investments in monumental architecture and statuary thus began soon after initial settlement."

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: have changed almost all of the previously posited early settlement dates in Polynesia

answers: NDQ_005718

answers: Rectifications in radiocarbon dating

answers: NDQ_005719

answers: NDQ_005720

answers: radiocarbon

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: Rectifications

answers: NDQ_005718

answers: Rectifications in radiocarbon

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: The history of coal exploration and mining dates back to 1968 when coal reserves where discovered in Anou Araren by an exploration team led by the French Atomic Commission Commissariat à l’énergie atomique. This discovery and the parallel discovery and exploitation of uranium mines in the same region of Niger lead to the creation of SONICHAR in 1975. The goal was to mine coal which will be used as a fuel to power the thermal power plants in order to supply power to uranium mining activities in Arlit. In 1980, coal mining began at Anou Araren and a year later, the thermal power plant was in operation. Since then, coal mining projects have stagnated. In 2008, coal reserves . In 2014, construction for the second coal mine began in Salkadamna in Takanamatt, Tahoua Region. The coal extracted from the mine will supply a 600 MW power plant and coal briquette plant adjacent to the mine.

text: The history of coal exploration and mining dates back to 1968 when coal reserves where discovered in Anou Araren by an exploration team led by the French Atomic Commission

entity_name: French Alternative Energies and Atomic Energy Commission

text: Commissariat à l’énergie atomique

text: . This discovery and the parallel discovery and exploitation of uranium mines in the same region of Niger lead to the creation of SONICHAR in 1975. The goal was to mine coal which will be used as a fuel to power the thermal power plants in order to supply power to uranium mining activities in Arlit. In 1980, coal mining began at Anou Araren and a year later, the thermal power plant was in operation. Since then, coal mining projects have stagnated. In 2008, coal reserves . In 2014, construction for the second coal mine began in

text: Salkadamna

text: in

text: Takanamatt

text: Tahoua Region

text: . The coal extracted from the mine will supply a 600 MW power plant and coal briquette plant adjacent to the mine.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating works for materials of these ages

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: How long does the half-life of carbon-14 decay?

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The goal was to mine coal

answers: NDQ_005718

answers: coal mining projects have stagnated

answers: NDQ_005719

answers: What is the purpose of potassium-argon and uranium-lead dating

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: French Atomic Commission

answers: NDQ_005712

answers: coal which will be used as a fuel to power the thermal power plants

answers: NDQ_005713

answers: coal reserves where discovered in Anou Araren

answers: NDQ_005714

answers: coal reserves where discovered in Anou Araren

answers: NDQ_005715

answers: coal reserves where discovered in Anou Araren

answers: NDQ_005716

answers: coal reserves where discovered in Anou Araren

answers: NDQ_005717

answers: 1968 when coal reserves where discovered in Anou Araren

answers: NDQ_005718

answers: coal mining projects have stagnated.

answers: NDQ_005719

answers: coal reserves where discovered in Anou Araren

answers: NDQ_005720

answers: coal reserves where discovered in Anou Araren

text: Two major reviews of the evidence were published in the mid-2000s. Both authors concluded that there were major technical flaws in each of the studies claiming independent invention.  Three major issues were identified. The first was whether the material dated by radiocarbon was in secure archaeological association with iron-working residues. (Many of the dates from Niger, for example, were on organic matter in potsherds that were lying on the ground surface together with iron objects). The second issue is the possible effect of "old carbon" - wood or charcoal much older than the time at which iron was smelted. This is a particular problem in Niger, where the charred stumps of ancient trees are a potential source of charcoal, and have sometimes been mis-identified as smelting furnaces. A third issue is the inherent lack of precision of the radiocarbon method itself in the range from 800 to 400 BC, which is attributable to irregular production of radiocarbon in the upper atmosphere. Unfortunately most radiocarbon dates for the initial spread of iron metallurgy in sub-Saharan Africa fall within this range.

text: Two major reviews of the evidence were published in the mid-2000s. Both authors concluded that there were major technical flaws in each of the studies claiming independent invention.  Three major issues were identified. The first was whether the material dated by radiocarbon was in secure archaeological association with iron-working residues. (Many of the dates from Niger, for example, were on organic matter in potsherds that were lying on the ground surface together with iron objects). The second issue is the possible effect of "old carbon" - wood or charcoal much older than the time at which iron was smelted. This is a particular problem in Niger, where the charred stumps of ancient trees are a potential source of charcoal, and have sometimes been mis-identified as smelting furnaces. A third issue is the inherent lack of precision of the radiocarbon method itself in the range from 800 to 400 BC, which is attributable to irregular production of radiocarbon in the upper atmosphere. Unfortunately most radiocarbon dates for the initial spread of iron metallurgy in sub-Saharan Africa fall within this range.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: irregular production of radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is produced in the upper atmosphere

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon was in secure archaeological association with iron-working residues

answers: NDQ_005718

answers: insecure archaeological association with iron-working residues

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: irregular production of radiocarbon in the upper atmosphere.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon was in secure archaeological association with iron-working residues.

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon

answers: NDQ_005717

answers: radiocarbon was in secure archaeological association with iron-working residues.

answers: NDQ_005718

answers: lack of precision

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon

text: The settlement has been dated by three radiocarbon dates from submerged branches:

text: The settlement has been dated by three

text: radiocarbon date

text: s from submerged branches:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: submerged branches:

answers: NDQ_005713

answers: radiocarbon dates from submerged branches:

answers: NDQ_005714

answers: radiocarbon dates from submerged branches:

answers: NDQ_005715

answers: radiocarbon dates from submerged branches:

answers: NDQ_005716

answers: radiocarbon dates from submerged branches:

answers: NDQ_005717

answers: submerged branches:

answers: NDQ_005718

answers: submerged branches:

answers: NDQ_005719

answers: radiocarbon dates from submerged branches:

answers: NDQ_005720

answers: three radiocarbon dates from submerged branches:

text: Between 56,000 and 32,000 years ago explosive volcanic activity occurred at Ciomadul. Both the exact dates of the various eruptions and of the formation of the St. Ana and Mohos craters are unclear, partly because dates obtained by potassium-argon dating and other dating techniques disagree with each other. Some eruptions may have reached sub-Plinian strength, ejecting volcanic ash as far as the Black Sea.

text: Between 56,000 and 32,000 years ago

text: explosive volcanic activity

text: occurred at Ciomadul. Both the exact dates of the various eruptions and of the formation of the St. Ana and Mohos craters are unclear, partly because dates obtained by

text: potassium-argon dating

text: and other dating techniques disagree with each other. Some eruptions may have reached sub-

text: Plinian

text: strength, ejecting

text: volcanic ash

text: as far as the

text: Black Sea

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: disagree with each other

answers: NDQ_005718

answers: dates obtained by potassium-argon dating and other dating techniques disagree with each other

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: dates obtained by potassium-argon

answers: NDQ_005715

answers: 32,000 years ago explosive volcanic activity occurred at Ciomadul.

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: disagree with each other.

answers: NDQ_005718

answers: disagree with each other.

answers: NDQ_005719

answers: potassium-argon dating

answers: NDQ_005720

answers: potassium-argon dating

text: A radiocarbon dating analysis of the papyrus by the Arizona Accelerator Mass Spectrometry Laboratory in 2013 dated the papyrus to between 404 and 209 BC. However, the cleaning protocol had to be interrupted during processing to preserve the fragment. A second analysis was performed by Harvard University and the Woods Hole Oceanographic Institution found a mean date of AD 741. A Raman spectroscopy analysis at Columbia University found that the ink was consistent with those in manuscripts from 400 BC to AD 700–800. These analyses suggest that the fragment as a material artifact is probably medieval and not modern.

text: A

text: radiocarbon dating

text: analysis of the papyrus by the

entity_name: Arizona Accelerator Mass Spectrometry Laboratory

text: Arizona Accelerator Mass Spectrometry Laboratory

text: in 2013 dated the papyrus to between 404 and 209 BC. However, the cleaning protocol had to be interrupted during processing to preserve the fragment. A second analysis was performed by

text: Harvard University

text: and the

text: Woods Hole Oceanographic Institution

text: found a mean date of AD 741. A

text: Raman spectroscopy

text: analysis at

text: Columbia University

text: found that the ink was consistent with those in manuscripts from 400 BC to AD 700–800. These analyses suggest that the fragment as a material artifact is probably medieval and not modern.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: radiocarbon dating

answers: NDQ_005718

answers: the cleaning protocol had to be interrupted during processing to preserve the fragment

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: medieval and not modern.

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: AD 741.

answers: NDQ_005716

answers: dated the papyrus to between 404 and 209 BC.

answers: NDQ_005717

answers: 404 and 209 BC.

answers: NDQ_005718

answers: the cleaning protocol had to be interrupted during processing to preserve the fragment.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating analysis of the papyrus

text: Keeping this principle in mind, Sam's leaps were generally limited to periods within his own lifetime; he could not leap to a date prior to his birth or into his own future. There were, however, a few exceptions. In "The Leap Back," Sam switched places with Al, who leaped back into 1945, and later in the episode was able to leap himself back into Al's place in the past. The explanation was that the simo-leap with Al had left Sam with enough of Al's genetic coding that he could leap back past his own lifetime (since it was still within Al's). In "The Leap Between the States," Sam was able to leap outside of his own lifetime and found himself in the American Civil War in the life of his great-grandfather; the explanation was that Sam's close genetic link with his ancestor allowed him to do this. This was also partly due to an "error" that was referenced and then corrected by Ziggy, implying that Sam would not be able to pull off a similar feat again and was once more limited to his own timeline. Two early episodes, "Play It Again, Seymour" (which took place on April 14, 1953) and "The Americanization of Machiko" (which took place on August 4, 1953) had Sam leaping into dates prior to the date later given as his birthday, August 8, 1953. Although these would appear to be continuity errors on the part of the show, creator Donald P. Bellisario has proffered the explanation that Sam's life dates from his conception rather than his actual birth, and thus dates such as these which are less than nine months prior to August 8, 1953, would be valid leap dates. However, once Sam's proper birthday is established, there are no further leaps prior to that date aside from the exceptions mentioned above.

text: Keeping this principle in mind, Sam's leaps were generally limited to periods within his own lifetime; he could not leap to a date prior to his birth or into his own future. There were, however, a few exceptions. In "The Leap Back," Sam switched places with Al, who leaped back into 1945, and later in the episode was able to leap himself back into Al's place in the past. The explanation was that the simo-leap with Al had left Sam with enough of Al's

text: genetic coding

text: that he could leap back past his own lifetime (since it was still within Al's). In "The Leap Between the States," Sam was able to leap outside of his own lifetime and found himself in the

text: American Civil War

text: in the life of his great-grandfather; the explanation was that Sam's close genetic link with his ancestor allowed him to do this. This was also partly due to an "error" that was referenced and then corrected by Ziggy, implying that Sam would not be able to pull off a similar feat again and was once more limited to his own timeline. Two early episodes, "Play It Again, Seymour" (which took place on April 14, 1953) and "The Americanization of Machiko" (which took place on August 4, 1953) had Sam leaping into dates prior to the date later given as his birthday, August 8, 1953. Although these would appear to be

text: continuity error

text: s on the part of the show, creator

text: Donald P. Bellisario

text: has proffered the explanation that Sam's life dates from his

text: conception

text: rather than his actual birth, and thus dates such as these which are less than nine months prior to August 8, 1953, would be valid leap dates. However, once Sam's proper birthday is established, there are no further leaps prior to that date aside from the exceptions mentioned above.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating

answers: NDQ_005713

answers: how does radiometric dating work

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Sam's life dates from his conception rather than his actual birth

answers: NDQ_005718

answers: Sam's leaps were generally limited to periods within his own lifetime

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: conception

answers: NDQ_005712

answers: Sam's life dates from his conception rather than his actual birth,

answers: NDQ_005713

answers: his conception

answers: NDQ_005714

answers: genetic coding

answers: NDQ_005715

answers: August 8, 1953.

answers: NDQ_005716

answers: Sam's life dates from his conception rather than his actual birth,

answers: NDQ_005717

answers: Sam's life dates from his conception rather than his actual birth,

answers: NDQ_005718

answers: he could not leap to a date prior to his birth

answers: NDQ_005719

answers: Sam

answers: NDQ_005720

answers: Sam would not be able to pull off a similar feat again

text: The Fruitland is underlain by the Pictured Cliffs Sandstone, and overlain by the more recent Kirtland Formation.  The sequence of rocks represents the final filling of the Cretaceous seaway.  The underlying Pictured Cliffs is a marginal marine sandstone, deposited in an environment similar to offshore barrier islands of the southeast United States.  As the seaway retreated, the Pictured Cliffs was covered by the Fruitland Formation, which was deposited in near-shore swampy lowlands. The formation is dated to the late Campanian (part of the Cretaceous period), and was deposited over a period of about a million years. Radiometric dating from just below the base of the formation has yielded an age of 75.56 ± 0.41 Ma ago. An ash bed lying below the upper boundary with the Kirtland Formation has been dated to 74.55 ± 0.29 Ma ago.

text: The Fruitland is underlain by the

text: Pictured Cliffs Sandstone

text: , and overlain by the more recent

text: Kirtland Formation

text: .  The sequence of rocks represents the final filling of the

text: Cretaceous

text: seaway

text: .  The underlying Pictured Cliffs is a marginal marine sandstone, deposited in an environment similar to offshore barrier islands of the southeast

text: United States

text: .  As the seaway retreated, the Pictured Cliffs was covered by the Fruitland Formation, which was deposited in near-shore swampy lowlands. The formation is dated to the late

text: Campanian

text: (part of the

text: Cretaceous

text: period), and was deposited over a period of about a million years. Radiometric dating from just below the base of the formation has yielded an age of 75.56 ± 0.41 Ma ago. An ash bed lying below the upper boundary with the Kirtland Formation has been dated to 74.55 ± 0.29 Ma ago.

answers: NDQ_005711

answers: radiometric

answers: NDQ_005712

answers: radiometric dating only works for materials of these ages

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: How many million years ago was the formation deposited?

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: age of 75.56  0.41 Ma ago

answers: NDQ_005718

answers: an age of 75.56  0.41 Ma ago

answers: NDQ_005719

answers: What is the formation dated to?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: from just below the base of the formation

answers: NDQ_005712

answers: 75.56 <unk> 0.41 Ma ago.

answers: NDQ_005713

answers: 75.56 <unk> 0.41 Ma ago.

answers: NDQ_005714

answers: Radiometric dating

answers: NDQ_005715

answers: late Campanian

answers: NDQ_005716

answers: Radiometric dating

answers: NDQ_005717

answers: 75.56 <unk> 0.41 Ma ago.

answers: NDQ_005718

answers: age of 75.56 <unk> 0.41 Ma ago.

answers: NDQ_005719

answers: Radiometric dating

answers: NDQ_005720

answers: Radiometric dating

text: Some proponents for the authenticity of the shroud have attempted to discount the radiocarbon dating result by claiming that the sample may represent a medieval "invisible" repair fragment rather than the image-bearing cloth. It has been suggested, for example, that burnt residue, or other types of residues, might have skewed the radiocarbon date toward the present. These various challenges have all been refuted by experts based on scientific analysis of shroud evidence. According to professor Christopher Ramsey of the Oxford Radiocarbon Accelerator Unit in 2011: "There are various hypotheses as to why the dates might not be correct, but none of them stack up."

text: Some proponents for the authenticity of the shroud have attempted to discount the radiocarbon dating result by claiming that the sample may represent a medieval "invisible" repair fragment rather than the image-bearing cloth. It has been suggested, for example, that burnt residue, or other types of residues, might have skewed the radiocarbon date toward the present. These various challenges have all been refuted by experts based on scientific analysis of shroud evidence. According to professor Christopher Ramsey of the Oxford Radiocarbon Accelerator Unit in 2011: "There are various hypotheses as to why the dates might not be correct, but none of them stack up."

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: radiocarbon

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon

answers: NDQ_005718

answers: There are various hypotheses as to why the dates might not be correct

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon

answers: NDQ_005715

answers: none of them stack up."

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: burnt residue,

answers: NDQ_005718

answers: the sample may represent a medieval "invisible" repair fragment

answers: NDQ_005719

answers: radiocarbon dating

answers: NDQ_005720

answers: radiocarbon dating

text: In boosted-fission nuclear weapons a mixture of deuterium and tritium are heated until there is thermonuclear fission to produce helium and release free neutrons. The flurry of fast neutron particles would then excite further fission reactions with uranium, creating a "boosted" nuclear bomb. In 1951, during Operation Greenhouse, a prototype named George, successfully validated the proof of concept for such a weapon. However, the first true boosted fission nuclear device, Greenhouse Item, was successfully tested in 1952, generating 45.5 kilotons of explosive yield, nearly double the value of an un-boosted system. The United States stopped producing tritium in nuclear reactors in 1988, but nuclear weapons testing in the 1950s added large spikes of radioactive elements to the atmosphere, especially radiocarbon and tritium. This complicated measurements for geologists using radiometric dating of carbon. However, some oceanographers benefited from the tritium increase, utilizing the signal in the water to trace physical mixing of water masses.

text: In

text: boosted-fission

text: nuclear weapons

text: a mixture of deuterium and tritium are heated until there is

text: thermonuclear fission

text: to produce helium and release free

text: neutrons

text: . The flurry of

text: fast neutron

text: particles would then excite further

text: fission reaction

text: s with

text: uranium

text: , creating a "boosted"

text: nuclear bomb

text: . In 1951, during

text: Operation Greenhouse

text: , a prototype named George, successfully validated the proof of concept for such a weapon. However, the first true

text: boosted fission nuclear device

text: Greenhouse Item

text: , was successfully tested in 1952, generating 45.5 kilotons of explosive yield, nearly double the value of an un-boosted system. The United States stopped producing tritium in

text: nuclear reactors

text: in 1988, but

text: nuclear weapons testing

text: in the 1950s added large spikes of

text: radioactive element

text: s to the atmosphere, especially

text: radiocarbon

text: and tritium. This complicated measurements for geologists using

text: radiometric dating of carbon

text: . However, some

text: oceanographers

text: benefited from the tritium increase, utilizing the signal in the water to trace

text: physical mixing

text: of water masses.

answers: NDQ_005711

answers: radioactive elements

answers: NDQ_005712

answers: radioactive elements to the atmosphere

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: radioactive elements to the atmosphere

answers: NDQ_005715

answers: unanswerable

answers: NDQ_005716

answers: radioactive elements to the atmosphere

answers: NDQ_005717

answers: This complicated measurements for geologists using radiometric dating of carbon

answers: NDQ_005718

answers: large spikes of radioactive elements to the atmosphere

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: carbon.

answers: NDQ_005712

answers: carbon.

answers: NDQ_005713

answers: nuclear weapons testing in the 1950s added large spikes of radioactive elements

answers: NDQ_005714

answers: radiometric dating of carbon.

answers: NDQ_005715

answers: tritium

answers: NDQ_005716

answers: carbon.

answers: NDQ_005717

answers: radiometric dating of carbon.

answers: NDQ_005718

answers: complicated measurements for geologists using radiometric dating of carbon.

answers: NDQ_005719

answers: radiometric dating

answers: NDQ_005720

answers: radiometric dating

text: Lead is perhaps the best example of a partly radiogenic substance, as all four of its stable isotopes (Pb, Pb, Pb, and Pb) are present primordially, in known and fixed ratios. However, Pb is only present primordially, while the other three isotopes may also occur as radiogenic decay products of uranium and thorium. Specifically, Pb is formed from U, Pb from U, and Pb from Th. In rocks that contain uranium and thorium, the excess amounts of the three heavier lead isotopes allows the rocks to be "dated," or the time estimate from when the rock solidified and the mineral held the ratio of isotopes fixed and in place.

text: Lead

text: is perhaps the best example of a partly radiogenic substance, as

text: all four of its stable isotopes

text: (Pb, Pb, Pb, and Pb) are present primordially, in known and fixed ratios. However, Pb is only present primordially, while the other three isotopes may also occur as radiogenic decay products of

text: uranium

text: and

text: thorium

text: . Specifically, Pb is formed from U, Pb from U, and Pb from Th. In rocks that contain uranium and thorium, the excess amounts of the three heavier lead isotopes allows the rocks to be "dated," or the time estimate from when the rock solidified and the mineral held the ratio of isotopes fixed and in place.

answers: NDQ_005711

answers: the time estimate from when the rock solidified

answers: NDQ_005712

answers: uranium and thorium

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium and thorium

answers: NDQ_005715

answers: NDQ_005716

answers: rock solidify

answers: NDQ_005717

answers: the excess amounts of the three heavier lead isotopes allows the rocks to be "dated

answers: NDQ_005718

answers: Pb is only present primordially

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: the mineral held the ratio of isotopes fixed and in place.

answers: NDQ_005712

answers: the excess amounts of the three heavier lead isotopes

answers: NDQ_005713

answers: uranium and thorium.

answers: NDQ_005714

answers: the excess amounts of the three heavier lead isotopes

answers: NDQ_005715

answers: Lead

answers: NDQ_005716

answers: the rock solidified

answers: NDQ_005717

answers: the excess amounts of the three heavier lead isotopes

answers: NDQ_005718

answers: Pb is only present primordially,

answers: NDQ_005719

answers: In rocks that contain uranium and thorium,

answers: NDQ_005720

answers: "dated,"

text: Two dating techniques were used to arrive at the approximate age of the beds that make up the ground layers at Laetoli: potassium-argon dating and analysis of stratigraphy. Based on these methods, the layers have been named as follows, starting with the deepest: Lower Laetolil Beds, Upper Laetolil Beds, Lower Ndolanya Beds, Upper Ndolanya Beds, Ogol lavas, Naibadad Beds, Olpiro Beds, and Ngaloba Beds; it is the ancient Laetolil Beds that contain the footprints trackway. The upper unit of the Laetolil Beds dated back 3.6 to 3.8 million years ago. The beds are dominantly tuffs and have a maximum thickness of 130 meters. No mammalian fauna were found in the lower unit of the Laetolil Beds, and no date could be assigned to this layer.

text: Two dating techniques were used to arrive at the approximate age of the beds that make up the ground layers at Laetoli:

text: potassium-argon dating

text: and analysis of

text: stratigraphy

text: . Based on these methods, the layers have been named as follows, starting with the deepest: Lower Laetolil Beds, Upper Laetolil Beds, Lower Ndolanya Beds, Upper Ndolanya Beds, Ogol lavas, Naibadad Beds, Olpiro Beds, and Ngaloba Beds; it is the ancient Laetolil Beds that contain the footprints trackway. The upper unit of the Laetolil Beds dated back 3.6 to 3.8 million years ago. The beds are dominantly tuffs and have a maximum thickness of 130 meters. No mammalian fauna were found in the lower unit of the Laetolil Beds, and no date could be assigned to this layer.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: NDQ_005716

answers: argon dating

answers: NDQ_005717

answers: two dating techniques were used to arrive at the approximate age

answers: NDQ_005718

answers: no date could be assigned to this layer

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: 3.6 to 3.8 million years ago.

answers: NDQ_005713

answers: potassium-argon dating

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: age of the beds that make up the ground layers at Laetoli:

answers: NDQ_005718

answers: No mammalian fauna were found in the lower unit

answers: NDQ_005719

answers: potassium-argon dating and analysis of stratigraphy.

answers: NDQ_005720

answers: potassium-argon dating

text: This scheme has application over a wide range of geologic dates. For dates up to a few million years micas, tektites (glass fragments from volcanic eruptions), and meteorites are best used. Older materials can be dated using zircon, apatite, titanite, epidote and garnet which have a variable amount of uranium content. Because the fission tracks are healed by temperatures over about 200 °C the technique has limitations as well as benefits. The technique has potential applications for detailing the thermal history of a deposit.

text: This scheme has application over a wide range of geologic dates. For dates up to a few million years

text: mica

text: s,

text: tektite

text: s (glass fragments from volcanic eruptions), and meteorites are best used. Older materials can be dated using

text: zircon

text: apatite

text: titanite

text: epidote

text: and

text: garnet

text: which have a variable amount of uranium content. Because the fission tracks are healed by temperatures over about 200 °C the technique has limitations as well as benefits. The technique has potential applications for detailing the thermal history of a deposit.

answers: NDQ_005711

answers: uranium

answers: NDQ_005712

answers: micas, tektites

answers: NDQ_005713

answers: NDQ_005714

answers: uranium is a noble element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: fission tracks heal

answers: NDQ_005717

answers: older materials can be dated using zircon, apatite, titanite, epidote and garnet which have a variable amount of uranium

answers: NDQ_005718

answers: fission tracks are healed by temperatures

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: uranium content.

answers: NDQ_005712

answers: up to a few million years

answers: NDQ_005713

answers: This scheme has application over a wide range of geologic dates.

answers: NDQ_005714

answers: the fission tracks are healed by temperatures over about 200 °C

answers: NDQ_005715

answers: the fission tracks are healed by temperatures over about 200 °C

answers: NDQ_005716

answers: uranium

answers: NDQ_005717

answers: the fission tracks are healed by temperatures over about 200 °C

answers: NDQ_005718

answers: the fission tracks are healed by temperatures over about 200 °C

answers: NDQ_005719

answers: micas,

answers: NDQ_005720

answers: uranium content.

text: Radioactivity, which had overthrown the old calculations, yielded a bonus by providing a basis for new calculations, in the form of radiometric dating.

text: Radioactivity, which had overthrown the old calculations, yielded a bonus by providing a basis for new calculations, in the form of

text: radiometric dating

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: radioactivity

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: carbon-14 is a decay product

answers: NDQ_005715

answers: NDQ_005716

answers: radioactivity decay

answers: NDQ_005717

answers: radiometric dating

answers: NDQ_005718

answers: radioactivity

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Radioactivity,

answers: NDQ_005712

answers: Radioactivity,

answers: NDQ_005713

answers: radiometric dating.

answers: NDQ_005714

answers: radiometric dating.

answers: NDQ_005715

answers: radiometric dating.

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: radiometric dating.

answers: NDQ_005718

answers: Radioactivity,

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: radiometric dating.

text: The Pleistocene has been dated from 2.588 million (±.005) to 11,700 years before present (BP), with the end date expressed in radiocarbon years as 10,000 carbon-14 years BP. It covers most of the latest period of repeated glaciation, up to and including the Younger Dryas cold spell. The end of the Younger Dryas has been dated to about 9640 BC (11,654 calendar years BP). It was not until after the development of radiocarbon dating, however, that Pleistocene archaeological excavations shifted to stratified caves and rock-shelters as opposed to open-air river-terrace sites.

text: The Pleistocene has been dated from 2.588 million (±.005) to 11,700 years

text: before present

text: (BP), with the end date expressed in

text: radiocarbon year

text: s as 10,000

text: years BP. It covers most of the latest period of repeated

text: glaciation

text: , up to and including the

text: Younger Dryas

text: cold spell. The end of the Younger Dryas has been dated to about 9640 BC (11,654 calendar years BP). It was not until after the development of radiocarbon dating, however, that Pleistocene archaeological excavations shifted to stratified caves and rock-shelters as opposed to open-air river-terrace sites.

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: radiocarbon is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: radiocarbon years as 10,000 carbon-14 years

answers: NDQ_005718

answers: open-air river-terrace sites

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: radiocarbon

answers: NDQ_005713

answers: radiocarbon

answers: NDQ_005714

answers: radiocarbon dating,

answers: NDQ_005715

answers: 10,000 carbon-14 years BP.

answers: NDQ_005716

answers: radiocarbon years as 10,000 carbon-14 years BP.

answers: NDQ_005717

answers: 10,000 carbon-14 years BP.

answers: NDQ_005718

answers: open-air river-terrace sites.

answers: NDQ_005719

answers: radiocarbon

answers: NDQ_005720

answers: radiocarbon dating,

text: More recent dating based on Ar-Ar, U-Pb (uranium-lead), and coccoliths shows a narrower range of ages from 56 Ma in the south to 50 or 49 Ma in the north.

text: More recent dating based on Ar-Ar, U-Pb (uranium-lead), and

text: coccoliths

text: shows a narrower range of ages from 56 Ma in the south to 50 or 49 Ma in the north.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: Ar-Ar

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: Ar-Ar

answers: NDQ_005717

answers: 56 Ma

answers: NDQ_005718

answers: narrower range of ages

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Ar-Ar,

answers: NDQ_005712

answers: narrower range of ages

answers: NDQ_005713

answers: Ar-Ar,

answers: NDQ_005714

answers: a narrower range of ages

answers: NDQ_005715

answers: Ar-Ar,

answers: NDQ_005716

answers: ages

answers: NDQ_005717

answers: 56 Ma in the south to 50 or 49 Ma in the north.

answers: NDQ_005718

answers: narrower range of ages

answers: NDQ_005719

answers: Ar-Ar,

answers: NDQ_005720

answers: Ar-Ar, U-Pb

text: Unlike carbon-14 dating, luminescence dating methods do not require a contemporary organic component of the sediment to be dated; just quartz, potassium feldspar, or certain other mineral grains that have been fully bleached during the event being dated. These methods also do not suffer from overestimation of dates when the sediment in question has been mixed with “old carbon”, or -deficient carbon that is not the same isotopic ratio as the atmosphere. In a study of the chronology of arid-zone lacustrine sediments from Lake Ulaan in southern Mongolia, Lee et al. discovered that OSL and radiocarbon dates agreed in some samples, but the radiocarbon dates were up to 5800 years older in others.

text: Unlike

text: carbon-14 dating

text: , luminescence dating methods do not require a contemporary organic component of the sediment to be dated; just quartz, potassium feldspar, or certain other mineral grains that have been fully bleached during the event being dated. These methods also do not suffer from overestimation of dates when the sediment in question has been mixed with “old carbon”, or -deficient carbon that is not the same isotopic ratio as the atmosphere. In a study of the chronology of arid-zone

text: lacustrine

text: sediments from

text: Lake Ulaan

text: in southern

text: Mongolia

text: , Lee et al. discovered that OSL and radiocarbon dates agreed in some samples, but the radiocarbon dates were up to 5800 years older in others.

answers: NDQ_005711

answers: carbon-14

answers: NDQ_005712

answers: luminescence

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: luminescence dating

answers: NDQ_005715

answers: NDQ_005716

answers: radiocarbon dating

answers: NDQ_005717

answers: luminescence dating methods

answers: NDQ_005718

answers: overestimation of dates

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: radiocarbon

answers: NDQ_005712

answers: luminescence dating methods do not require a contemporary organic component

answers: NDQ_005713

answers: radiocarbon dates were up to 5800 years older in others.

answers: NDQ_005714

answers: luminescence dating methods do not require a contemporary organic component

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: carbon-14 dating,

answers: NDQ_005717

answers: luminescence dating methods do not require a contemporary organic component

answers: NDQ_005718

answers: overestimation of dates

answers: NDQ_005719

answers: luminescence

answers: NDQ_005720

answers: carbon-14 dating,

text: So-called "centralised" (European Medicines Agency / European Commission) MAs were introduced by Regulation 2309/93 and became available in January 1995 (i.e. some 2 years after the introduction of the original SPC legislation for medicinal products). The introduction of these authorisations added a new layer of complexity to the issue of determination of the date of a MA. This is because there are two dates associated with "centralised" authorisations, namely: (1) the date of the European Commission's decision to issue an authorisation; and (2) the date of notification of that decision to the MA applicant.  Date (2) is usually a few days (e.g. 2 to 4 days) later than date (1).  Although the standard practice of many national patent offices seems to be to calculate SPC term based upon date (1), an October 2011 article in Scrip Regulatory Affairs by Mike Snodin argues that this standard practice is incorrect and that date (2) should be used instead (with the result that some products may be entitled to a slightly longer SPC term than previously thought). Paramount amongst the reasons for preferring date (2) to date (1) is that a "centralised" authorisation does not become effective until it is notified to the MA applicant.

text: So-called "centralised" (

text: European Medicines Agency

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: date (2)

answers: NDQ_005713

answers: unanswerable

answers: NDQ_005714

answers: date (2) should be used instead

answers: NDQ_005715

answers: half-life of 5,730 years

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Date (2) is usually a few days (e.g. 2 to 4 days later than date (1)

answers: NDQ_005718

answers: Date (2) is usually a few days (e.g. 2 to 4 days) later than date (1)

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: Regulation 2309/93

answers: NDQ_005712

answers: medicinal products).

answers: NDQ_005713

answers: 1995

answers: NDQ_005714

answers: does not become effective until it is notified to the MA applicant.

answers: NDQ_005715

answers: 1995

answers: NDQ_005716

answers: notified to the MA applicant.

answers: NDQ_005717

answers: Date (2)

answers: NDQ_005718

answers: does not become effective until it is notified to the MA applicant.

answers: NDQ_005719

answers: 1995

answers: NDQ_005720

answers: 1995

text: Two radiometric dating methods involve thorium isotopes: uranium-thorium dating, involving the decay of U to Th (ionium), and ionium-thorium dating, which measures the ratio of Th to Th. These rely on the fact that Th is a primordial radioisotope, but Th only occurs as an intermediate decay product in the decay chain of U. Uranium-thorium dating is a relatively short-range process because of the short half-lives of U and Th relative to the age of the Earth: it is also accompanied by a sister process involving the alpha decay of U into Th, which very quickly becomes the longer-lived Pa, and this process is often used to check the results of uranium-thorium dating. Uranium-thorium dating is commonly used to determine the age of calcium carbonate materials such as speleothem or coral, because while uranium is rather soluble in water, thorium and protactinium are not, and so they are selectively precipitated into ocean-floor sediments, from which their ratios are measured. The scheme has a range of several hundred thousand years. Ionium-thorium dating is a related process, which exploits the insolubility of thorium (both Th and Th) and thus its presence in ocean sediments to date these sediments by measuring the ratio of Th to Th. Both of these dating methods assume that the proportion of Th to Th is a constant during the time period when the sediment layer was formed, that the sediment did not already contain thorium before contributions from the decay of uranium, and that the thorium cannot shift within the sediment layer.

text: Two radiometric dating methods involve thorium isotopes:

text: uranium-thorium dating

text: , involving the decay of

text: U

text: to Th (ionium), and ionium-thorium dating, which measures the ratio of Th to Th. These rely on the fact that Th is a primordial radioisotope, but Th only occurs as an intermediate decay product in the decay chain of U. Uranium-thorium dating is a relatively short-range process because of the short half-lives of U and Th relative to the age of the Earth: it is also accompanied by a sister process involving the alpha decay of U into Th, which very quickly becomes the longer-lived Pa, and this process is often used to check the results of uranium-thorium dating. Uranium-thorium dating is commonly used to determine the age of

text: calcium carbonate

text: materials such as

text: speleothem

text: or

text: coral

text: , because while uranium is rather soluble in water, thorium and protactinium are not, and so they are selectively precipitated into ocean-floor

text: sediment

text: s, from which their ratios are measured. The scheme has a range of several hundred thousand years. Ionium-thorium dating is a related process, which exploits the insolubility of thorium (both Th and Th) and thus its presence in ocean sediments to date these sediments by measuring the ratio of Th to Th. Both of these dating methods assume that the proportion of Th to Th is a constant during the time period when the sediment layer was formed, that the sediment did not already contain thorium before contributions from the decay of uranium, and that the thorium cannot shift within the sediment layer.

answers: NDQ_005711

answers: uranium-thorium dating

answers: NDQ_005712

answers: uranium is rather soluble in water

answers: NDQ_005713

answers: yes

answers: NDQ_005714

answers: thorium isotopes

answers: NDQ_005715

answers: half-lives

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: ionium-thorium dating

answers: NDQ_005718

answers: short half-lives

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: measuring the ratio of Th to Th.

answers: NDQ_005712

answers: several hundred thousand years.

answers: NDQ_005713

answers: thorium isotopes:

answers: NDQ_005714

answers: Ionium-thorium dating

answers: NDQ_005715

answers: Ionium-thorium dating

answers: NDQ_005716

answers: they are selectively precipitated into ocean-floor sediments,

answers: NDQ_005717

answers: Ionium-thorium dating

answers: NDQ_005718

answers: short-range process

answers: NDQ_005719

answers: Ionium-thorium

answers: NDQ_005720

answers: Ionium-thorium dating

text: Most of the caldera's eruptive products have been heavily eroded by alpine glaciers and are now exposed in precipitous slopes extending from near sea level to elevations less than . The bulk of the complex appears to have been erupted between 100,000 and 500,000 years ago, but postglacial andesitic and basaltic andesite cones and lava flows are also present. Anomalously old potassium-argon dates of 1,000,000 and 1,100,000 years were obtained from a large lava flow at least  long in the postglacial Pashleth Creek and Machmell River valleys. This blocky lava flow is clearly much younger than the potassium-argon date, and high-energy glacial streams have only begun to etch a channel along the margin of the lava flow. The younger andesitic rocks issued from a cluster of vents, now mostly ice-covered, ranged around the periphery of the caldera. At high elevations, proximal breccia and cinders from several eroded cones rest on coarse colluvium derived from the older parts of the volcanic complex. The presence of unconsolidated glacial fluvial deposits under the flow suggest that it is less than 1,000 years old.

text: Most of the caldera's eruptive products have been heavily eroded by alpine glaciers and are now exposed in precipitous slopes extending from near sea level to elevations less than . The bulk of the complex appears to have been erupted between 100,000 and 500,000 years ago, but postglacial

text: andesitic

text: and

text: basaltic andesite

text: cones and lava flows are also present. Anomalously old

text: potassium-argon dates

text: of 1,000,000 and 1,100,000 years were obtained from a large lava flow at least  long in the postglacial Pashleth Creek and

text: Machmell River

text: valleys. This blocky lava flow is clearly much younger than the potassium-argon date, and high-energy glacial streams have only begun to etch a channel along the margin of the lava flow. The younger andesitic rocks issued from a cluster of vents, now mostly ice-covered, ranged around the periphery of the caldera. At high elevations, proximal

text: breccia

text: and

text: cinder

text: s from several eroded cones rest on coarse colluvium derived from the older parts of the volcanic complex. The presence of unconsolidated glacial fluvial deposits under the flow suggest that it is less than 1,000 years old.

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: potassium-argon

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: How old is potassium-argon?

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: this blocky lava flow is clearly much younger than the potassium-argon date

answers: NDQ_005718

answers: Anomalously old potassium-argon

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: potassium-argon

answers: NDQ_005712

answers: between 100,000 and 500,000 years ago,

answers: NDQ_005713

answers: potassium-argon dates of 1,000,000 and 1,100,000 years

answers: NDQ_005714

answers: potassium-argon

answers: NDQ_005715

answers: potassium-argon

answers: NDQ_005716

answers: potassium-argon

answers: NDQ_005717

answers: 1,000,000 and 1,100,000 years

answers: NDQ_005718

answers: Anomalously old

answers: NDQ_005719

answers: lava flow is clearly much younger than the potassium-argon date,

answers: NDQ_005720

answers: 1,000,000 and 1,100,000 years

text: Providing calendrical dates and ordered chronological sequences in the study of early stone tool manufacture is often accomplished through one or more geological techniques, such as  radiometric dating, often potassium-argon dating, and magnetostratigraphy.  From the Konso Formation of Ethiopia, Acheulean hand-axes are dated to about 1.5 million years ago using radiometric dating of deposits containing volcanic ashes. Acheulean tools in South Asia have also been found to be dated as far as 1.5 million years ago. However, the earliest accepted examples of the Acheulean currently known come from the West Turkana region of Kenya and were first described by a French-led archaeology team.  These particular Acheulean tools were recently dated through the method of magnetostratigraphy to about 1.76 million years ago, making them the oldest not only in Africa but the world. The earliest user of Acheulean tools was Homo ergaster, who first appeared about 1.8  million years ago. Not all researchers use this formal name, and instead prefer to call these users early Homo erectus.

text: Providing calendrical dates and ordered chronological sequences in the study of early stone tool manufacture is often accomplished through one or more geological techniques, such as

text: radiometric dating

text: , often

text: potassium-argon dating

text: , and

text: magnetostratigraphy

text: .  From the

text: Konso Formation

text: of Ethiopia, Acheulean hand-axes are dated to about 1.5 million years ago using

text: radiometric dating

text: of deposits containing volcanic ashes. Acheulean tools in South Asia have also been found to be dated as far as 1.5 million years ago. However, the earliest accepted examples of the Acheulean currently known come from the

text: West Turkana

text: region of

text: Kenya

text: and were first described by a French-led archaeology team.  These particular Acheulean tools were recently dated through the method of

text: magnetostratigraphy

text: to about 1.76 million years ago, making them the oldest not only in Africa but the world. The earliest user of Acheulean tools was

text: Homo ergaster

text: , who first appeared about 1.8  million years ago. Not all researchers use this formal name, and instead prefer to call these users early

text: Homo erectus

answers: NDQ_005711

answers: geological techniques

answers: NDQ_005712

answers: volcanic ashes

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: potassium-argon dating

answers: NDQ_005715

answers: radiometric dating

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: potassium-argon dating

answers: NDQ_005718

answers: volcanic ashes

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: deposits containing volcanic ashes.

answers: NDQ_005712

answers: volcanic ashes.

answers: NDQ_005713

answers: radiometric dating of deposits containing volcanic ashes.

answers: NDQ_005714

answers: Providing calendrical dates and ordered chronological sequences

answers: NDQ_005715

answers: 1.8

answers: NDQ_005716

answers: volcanic ashes.

answers: NDQ_005717

answers: Providing calendrical dates and ordered chronological sequences

answers: NDQ_005718

answers: deposits containing volcanic ashes.

answers: NDQ_005719

answers: radiometric dating,

answers: NDQ_005720

answers: potassium-argon dating, and magnetostratigraphy.

text: Radiocarbon dating is a radiometric dating method that uses (C) to determine the age of carbonaceous materials up to about 60,000 years old. The technique was developed by Willard Libby and his colleagues in 1949 during his tenure as a professor at the University of Chicago. Libby estimated that the radioactivity of exchangeable carbon-14 would be about 14 disintegrations per minute (dpm) per gram of pure carbon, and this is still used as the activity of the modern radiocarbon standard. In 1960, Libby was awarded the Nobel Prize in chemistry for this work.

text: Radiocarbon dating is a

text: radiometric dating

text: method that uses (C) to determine the age of

text: carbon

text: aceous materials up to about 60,000 years old. The technique was developed by

text: Willard Libby

text: and his colleagues in 1949 during his tenure as a professor at the

text: University of Chicago

text: . Libby estimated that the radioactivity of exchangeable carbon-14 would be about 14 disintegrations per minute (dpm) per gram of pure carbon, and this is still used as the activity of the modern radiocarbon standard. In 1960, Libby was awarded the

text: Nobel Prize in chemistry

text: for this work.

answers: NDQ_005711

answers: Radiocarbon dating

answers: NDQ_005712

answers: 60,000 years old

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: 14 disintegrations per minute

answers: NDQ_005715

answers: NDQ_005716

answers: carbon-14 decay

answers: NDQ_005717

answers: 14 disintegrations per minute

answers: NDQ_005718

answers: 60,000 years old

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: (C)

answers: NDQ_005712

answers: carbonaceous materials up to about 60,000 years old.

answers: NDQ_005713

answers: 60,000 years old.

answers: NDQ_005714

answers: 60,000 years old.

answers: NDQ_005715

answers: carbon-14

answers: NDQ_005716

answers: (C) to determine the age of carbonaceous materials

answers: NDQ_005717

answers: 14 disintegrations per minute

answers: NDQ_005718

answers: 60,000 years old.

answers: NDQ_005719

answers: Radiocarbon dating

answers: NDQ_005720

answers: Radiocarbon dating

text: Whereas many platter lifts are fairly similar to T-bars and J-bars with the stick attached to a spring box by a retractable cord, Pomas have a detachable grip to the tow cable with the button connected to the grip by a semi-rigid pole. Because they are detachable, most Pomas operate at speeds of around  per second, while platters and T-bars average . When a Poma's grip attaches to the cable, the passenger's acceleration is lessened by the spring-loaded pole (however on faster lifts there can still be quite a jerk when the pole becomes fully extended). The  Summit Access / Howqua Poma at Mount Buller, Australia, operated at a swift  when it was built in 1964.

text: Whereas many platter lifts are fairly similar to T-bars and J-bars with the stick attached to a spring box by a retractable cord, Pomas have a detachable grip to the tow cable with the button connected to the grip by a semi-rigid pole. Because they are detachable, most Pomas operate at speeds of around  per second, while platters and T-bars average . When a Poma's grip attaches to the cable, the passenger's acceleration is lessened by the spring-loaded pole (however on faster lifts there can still be quite a jerk when the pole becomes fully extended). The  Summit Access / Howqua Poma at

text: Mount Buller

text: Australia

text: , operated at a swift  when it was built in 1964.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: The Summit Access / Howqua Poma at Mount Buller

answers: NDQ_005718

answers: jerk when the pole becomes fully extended

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 1964.

answers: NDQ_005712

answers: 1964.

answers: NDQ_005713

answers: speeds of around per second,

answers: NDQ_005714

answers: speeds of around per second,

answers: NDQ_005715

answers: speeds of around per second,

answers: NDQ_005716

answers: 1964.

answers: NDQ_005717

answers: 1964.

answers: NDQ_005718

answers: jerk when the pole becomes fully extended).

answers: NDQ_005719

answers: 1964.

answers: NDQ_005720

answers: Pomas operate at speeds of around per second,

text: Wizard and warlock usually refer to a male, while witch usually refers to a female. In Witch World, a man who anomalously showed the same abilities as a witch was called a warlock. The term warlock is sometimes used to indicate a male witch in fiction. However, either term may be used in a unisex manner, in which case there will be members of both sexes bearing that title. If both terms are used in the same setting, this can indicate a gender-based title for practitioners of identical magic, such as in Harry Potter, or it can indicate that the two sexes practice different types of magic, as in Discworld.

text: Wizard and warlock usually refer to a male, while witch usually refers to a female. In

text: Witch World

text: , a man who anomalously showed the same abilities as a witch was called a warlock. The term warlock is sometimes used to indicate a male witch in fiction. However, either term may be used in a unisex manner, in which case there will be members of both sexes bearing that title. If both terms are used in the same setting, this can indicate a gender-based title for practitioners of identical magic, such as in

text: Harry Potter

text: , or it can indicate that the two sexes practice different types of magic, as in

text: Discworld

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: warlock is sometimes used to indicate a male witch

answers: NDQ_005718

answers: unanswerable

answers: NDQ_005719

answers: NDQ_005720

answers: NDQ_005711

answers: members of both sexes

answers: NDQ_005712

answers: members of both sexes

answers: NDQ_005713

answers: Wizard and warlock usually refer to a male, while witch

answers: NDQ_005714

answers: gender-based title for practitioners of identical magic,

answers: NDQ_005715

answers: warlock.

answers: NDQ_005716

answers: Wizard

answers: NDQ_005717

answers: members of both sexes

answers: NDQ_005718

answers: members of both sexes

answers: NDQ_005719

answers: Wizard

answers: NDQ_005720

answers: Wizard

text: Several of the isotope systems involved in radiometric dating depend on IRMS using thermal ionization of a solid sample loaded into the source of the mass spectrometer (hence thermal ionization mass spectrometry, TIMS). These methods include rubidium-strontium dating, uranium-lead dating, lead-lead dating and samarium-neodymium dating.

text: Several of the isotope systems involved in

text: radiometric dating

text: depend on IRMS using

text: thermal ionization

text: of a solid sample loaded into the source of the mass spectrometer (hence

text: thermal ionization mass spectrometry

text: , TIMS). These methods include

text: rubidium-strontium dating

text: uranium-lead dating

text: lead-lead dating

text: and

text: samarium-neodymium dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: thermal ionization mass spectrometer

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: thermal ionization mass spectrometry

answers: NDQ_005715

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: thermal ionization

answers: NDQ_005718

answers: thermal ionization of a solid sample

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: thermal ionization

answers: NDQ_005712

answers: thermal ionization of a solid sample

answers: NDQ_005713

answers: thermal ionization mass spectrometry, TIMS).

answers: NDQ_005714

answers: radiometric dating

answers: NDQ_005715

answers: thermal ionization mass spectrometry, TIMS).

answers: NDQ_005716

answers: radiometric dating

answers: NDQ_005717

answers: samarium-neodymium

answers: NDQ_005718

answers: thermal ionization of a solid sample

answers: NDQ_005719

answers: samarium-neodymium dating.

answers: NDQ_005720

answers: uranium-lead dating,

text: The Isla Escudo de Veraguas is the primary island in the gulf.

text: The

text: Isla Escudo de Veraguas

text: is the primary island in the gulf.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating is not reliable

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: Isla Escudo de Veraguas is the primary island in the gulf.

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: The Isla Escudo de Veraguas

answers: NDQ_005712

answers: The Isla Escudo de Veraguas

answers: NDQ_005713

answers: The Isla Escudo de Veraguas

answers: NDQ_005714

answers: The Isla Escudo de Veraguas

answers: NDQ_005715

answers: The Isla Escudo de Veraguas

answers: NDQ_005716

answers: The Isla Escudo de Veraguas

answers: NDQ_005717

answers: The Isla Escudo de Veraguas

answers: NDQ_005718

answers: The Isla Escudo de Veraguas

answers: NDQ_005719

answers: The Isla Escudo de Veraguas

answers: NDQ_005720

answers: The Isla Escudo de Veraguas

text: Fred H. Teale served as Los Angeles City Auditor from 1892 until 1896.

text: Fred H. Teale served as

text: Los Angeles City Auditor

text: from 1892 until 1896.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay is not present

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: was fred h. teale born?

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 1892 until 1896.

answers: NDQ_005712

answers: 1892 until 1896.

answers: NDQ_005713

answers: 1892 until 1896.

answers: NDQ_005714

answers: 1892 until 1896.

answers: NDQ_005715

answers: Fred H. Teale served as Los Angeles City Auditor from 1892

answers: NDQ_005716

answers: 1892 until 1896.

answers: NDQ_005717

answers: Fred H. Teale

answers: NDQ_005718

answers: 1896.

answers: NDQ_005719

answers: Fred H. Teale served as Los Angeles City Auditor from 1892

answers: NDQ_005720

answers: Fred H. Teale served as Los Angeles City Auditor from 1892

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay is present

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 is a radioactive element.

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: can be used to determine the age of uranium

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: What is the best way to determine the age of a material?

answers: NDQ_005720

answers: how old is zircon?

answers: NDQ_005711

answers: pt:SP-176

answers: NDQ_005712

answers: pt:SP-176

answers: NDQ_005713

answers: pt:SP-176

answers: NDQ_005714

answers: pt:SP-176

answers: NDQ_005715

answers: pt:SP-176

answers: NDQ_005716

answers: pt:SP-176

answers: NDQ_005717

answers: pt:SP-176

answers: NDQ_005718

answers: pt:SP-176

answers: NDQ_005719

answers: pt:SP-176

answers: NDQ_005720

answers: pt:SP-176

text: In 2008, Linspire was acquired and then discontinued by Xandros. Originally derived from Linspire, Freespire is a distribution that has continued some of Linspire's legacy.

text: In 2008, Linspire was acquired and then discontinued by

text: Xandros

text: . Originally derived from Linspire,

text: Freespire

text: is a distribution that has continued some of Linspire's legacy.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: Freespire has continued some of Linspire's legacy.

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: uranium-lead

answers: NDQ_005720

answers: NDQ_005711

answers: Xandros.

answers: NDQ_005712

answers: In 2008, Linspire was acquired and then discontinued by Xandros.

answers: NDQ_005713

answers: Freespire

answers: NDQ_005714

answers: Linspire was acquired and then discontinued by Xandros.

answers: NDQ_005715

answers: In 2008, Linspire was acquired and then discontinued by Xandros.

answers: NDQ_005716

answers: Linspire was acquired and then discontinued by Xandros.

answers: NDQ_005717

answers: Linspire was acquired and then discontinued by Xandros.

answers: NDQ_005718

answers: discontinued by Xandros.

answers: NDQ_005719

answers: In 2008, Linspire was acquired and then discontinued by Xandros.

answers: NDQ_005720

answers: Linspire was acquired and then discontinued by Xandros.

text: St. John the Baptist Parish has no incorporated areas.

text: St. John the Baptist Parish has no

text: incorporated

text: areas.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay is not present

answers: NDQ_005713

answers: None of the above choices.

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: no

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: St. John the Baptist has no incorporated areas.

answers: NDQ_005718

answers: no incorporated areas

answers: NDQ_005719

answers: None of the above choices.

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: incorporated areas.

answers: NDQ_005712

answers: St. John the Baptist Parish has no incorporated areas.

answers: NDQ_005713

answers: St. John the Baptist Parish has no incorporated areas.

answers: NDQ_005714

answers: St. John the Baptist Parish has no incorporated areas.

answers: NDQ_005715

answers: St. John the Baptist Parish has no incorporated areas.

answers: NDQ_005716

answers: incorporated areas.

answers: NDQ_005717

answers: St. John the Baptist Parish has no incorporated areas.

answers: NDQ_005718

answers: incorporated areas.

answers: NDQ_005719

answers: St. John the Baptist Parish has no incorporated areas.

answers: NDQ_005720

answers: St. John the Baptist Parish has no incorporated areas.

text: After the discovery of X-rays by Wilhelm Röntgen, many scientists began to work on ionizing radiation. One of these was Henri Becquerel, who investigated the relationship between phosphorescence and the blackening of photographic plates. When Becquerel (working in France) discovered that, with no external source of energy, the uranium generated rays which could blacken (or fog) the photographic plate, radioactivity was discovered. Marie Curie (working in Paris) and her husband Pierre Curie isolated two new radioactive elements from uranium ore. They used radiometric methods to identify which stream the radioactivity was in after each chemical separation; they separated the uranium ore into each of the different chemical elements that were known at the time, and measured the radioactivity of each fraction. They then attempted to separate these radioactive fractions further, to isolate a smaller fraction with a higher specific activity (radioactivity divided by mass). In this way, they isolated polonium and radium. It was noticed in about 1901 that high doses of radiation could cause an injury in humans. Henri Becquerel had carried a sample of radium in his pocket and as a result he suffered a high localised dose which resulted in a radiation burn. This injury resulted in the biological properties of radiation being investigated, which in time resulted in the development of medical treatments.

text: After the discovery of

text: X-ray

text: s by

text: Wilhelm Röntgen

text: , many scientists began to work on ionizing radiation. One of these was

text: Henri Becquerel

text: , who investigated the relationship between

text: phosphorescence

text: and the blackening of

text: photographic plate

text: s. When Becquerel (working in France) discovered that, with no external source of energy, the uranium generated rays which could blacken (or fog) the photographic plate, radioactivity was discovered.

text: Marie Curie

text: (working in Paris) and her husband

text: Pierre Curie

text: isolated two new radioactive elements from uranium ore. They used

text: radiometric

text: methods to identify which stream the radioactivity was in after each chemical separation; they separated the uranium ore into each of the different chemical elements that were known at the time, and measured the radioactivity of each fraction. They then attempted to separate these radioactive fractions further, to isolate a smaller fraction with a higher specific activity (radioactivity divided by mass). In this way, they isolated

text: polonium

text: and

text: radium

text: . It was noticed in about 1901 that high doses of radiation could cause an injury in humans.

text: Henri Becquerel

text: had carried a sample of radium in his pocket and as a result he suffered a high localised dose which resulted in a

text: radiation burn

text: . This injury resulted in the biological properties of radiation being investigated, which in time resulted in the development of medical treatments.

answers: NDQ_005711

answers: radioactivity

answers: NDQ_005712

answers: uranium

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: radioactive elements

answers: NDQ_005717

answers: radium

answers: NDQ_005718

answers: high doses of radiation could cause an injury

answers: NDQ_005719

answers: What is the purpose of potassium-argon and uranium-lead dating?

answers: NDQ_005720

answers: unanswerable

answers: NDQ_005711

answers: measured the radioactivity of each fraction.

answers: NDQ_005712

answers: different chemical elements that were known at the time,

answers: NDQ_005713

answers: radiometric methods

answers: NDQ_005714

answers: ionizing radiation.

answers: NDQ_005715

answers: polonium and radium.

answers: NDQ_005716

answers: measured the radioactivity

answers: NDQ_005717

answers: polonium and radium.

answers: NDQ_005718

answers: (radioactivity divided by mass).

answers: NDQ_005719

answers: radiometric methods

answers: NDQ_005720

answers: radiometric methods

text: The chemists had to find a way of producing quantities of uranium tetrachloride () from uranium oxide. (Nier had used uranium bromide.) Initially, they produced it by using hydrogen to reduce uranium trioxide () to uranium dioxide (), which was then reacted with carbon tetrachloride () to produce uranium tetrachloride. Charles A. Kraus proposed a better method for large-scale production that involved reacting the uranium oxide with carbon tetrachloride at high temperature and pressure. This produced uranium pentachloride () and phosgene (). While nowhere near as nasty as the uranium hexafluoride used by the gaseous diffusion process, uranium tetrachloride is hygroscopic, so work with it had to be undertaken in gloveboxes that were kept dry with phosphorus pentoxide (). The presence of phosgene, a lethal gas, required that the chemists wore gas masks when handling it.

text: The chemists had to find a way of producing quantities of uranium tetrachloride () from

text: uranium oxide

text: . (Nier had used uranium bromide.) Initially, they produced it by using hydrogen to reduce

text: uranium trioxide

text: () to

text: uranium dioxide

text: (), which was then reacted with

text: carbon tetrachloride

text: () to produce uranium tetrachloride.

text: Charles A. Kraus

text: proposed a better method for large-scale production that involved reacting the uranium oxide with carbon tetrachloride at high temperature and pressure. This produced

text: uranium pentachloride

text: () and

text: phosgene

text: (). While nowhere near as nasty as the

text: uranium hexafluoride

text: used by the gaseous diffusion process, uranium tetrachloride is

text: hygroscopic

text: , so work with it had to be undertaken in

text: glovebox

text: es that were kept dry with

text: phosphorus pentoxide

text: (). The presence of phosgene, a lethal gas, required that the chemists wore gas masks when handling it.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: uranium pentachloride

answers: NDQ_005713

answers: How does radiometric dating work?

answers: NDQ_005714

answers: carbon-14 dating is used for dating human remains

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating measures when the organism died

answers: NDQ_005717

answers: uranium pentachloride

answers: NDQ_005718

answers: hygroscopic

answers: NDQ_005719

answers: unanswerable

answers: NDQ_005720

answers: NDQ_005711

answers: uranium tetrachloride

answers: NDQ_005712

answers: uranium tetrachloride

answers: NDQ_005713

answers: carbon tetrachloride

answers: NDQ_005714

answers: carbon tetrachloride

answers: NDQ_005715

answers: carbon tetrachloride

answers: NDQ_005716

answers: carbon tetrachloride

answers: NDQ_005717

answers: phosgene

answers: NDQ_005718

answers: hygroscopic,

answers: NDQ_005719

answers: uranium tetrachloride

answers: NDQ_005720

answers: uranium tetrachloride

text: Torneo Violentango 4: 1st place

text: Torneo Violentango 4: 1st place

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating is not accurate

answers: NDQ_005713

answers: radiometric dating uses the rate of decay

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: 1st

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 1st place

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: None of the above choices .

answers: NDQ_005720

answers: None of the above choices .

answers: NDQ_005711

answers: Torneo Violentango 4: 1st place

answers: NDQ_005712

answers: Torneo Violentango 4:

answers: NDQ_005713

answers: Torneo Violentango 4: 1st

answers: NDQ_005714

answers: Torneo Violentango 4:

answers: NDQ_005715

answers: Torneo Violentango 4:

answers: NDQ_005716

answers: Torneo Violentango

answers: NDQ_005717

answers: Torneo Violentango 4: 1st place

answers: NDQ_005718

answers: context: Torneo Violentango 4:

answers: NDQ_005719

answers: Torneo Violentango 4:

answers: NDQ_005720

answers: Torneo Violentango 4: 1st place

text: The standard for the determination of soil salinity is from an extract of a saturated paste of the soil, and the EC is then written as ECe. The extract is obtained by centrifugation. The salinity can more easily be measured, without centrifugation, in a 2:1 or 5:1 water:soil mixture (in terms of g water per g dry soil) than from a saturated paste. The relation between ECe and EC is about 4, hence : ECe = 4 EC.

text: The standard for the determination of soil salinity is from an extract of a saturated paste of the soil, and the EC is then written as ECe. The extract is obtained by

text: centrifugation

text: . The salinity can more easily be measured, without centrifugation, in a 2:1 or 5:1 water:soil mixture (in terms of g water per g dry soil) than from a saturated paste. The relation between ECe and EC is about 4, hence : ECe = 4 EC.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating only works for materials

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a stable isotope

answers: NDQ_005715

answers: half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: ECe = 4 EC

answers: NDQ_005718

answers: The salinity can more easily be measured

answers: NDQ_005719

answers: are useful for very young materials

answers: NDQ_005720

answers: NDQ_005711

answers: centrifugation.

answers: NDQ_005712

answers: 2:1 or 5:1

answers: NDQ_005713

answers: ECe. The extract is obtained by centrifugation.

answers: NDQ_005714

answers: The standard for the determination of soil salinity

answers: NDQ_005715

answers: 4,

answers: NDQ_005716

answers: centrifugation.

answers: NDQ_005717

answers: ECe = 4 EC.

answers: NDQ_005718

answers: The salinity can more easily be measured, without centrifugation,

answers: NDQ_005719

answers: The standard for the determination of soil salinity

answers: NDQ_005720

answers: 4,

text: On Zola:

text: On Zola:

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay

answers: NDQ_005713

answers: radiometric dating uses the rate of decay of unstable isotopes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: How long does it take for carbon-14 to decay?

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: What is the most common method for determining the age of minerals?

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: uranium-lead

answers: NDQ_005720

answers: How old are zircon crystals?

answers: NDQ_005711

answers: Zola:

answers: NDQ_005712

answers: Zola:

answers: NDQ_005713

answers: Zola:

answers: NDQ_005714

answers: Zola:

answers: NDQ_005715

answers: Zola:

answers: NDQ_005716

answers: Zola:

answers: NDQ_005717

answers: Zola:

answers: NDQ_005718

answers: Zola:

answers: NDQ_005719

answers: Zola:

answers: NDQ_005720

answers: Zola:

text: The dating of the skull has been a subject of debate. Uranium-series dating of ox teeth from the site obtained a date of 209,000 ±23,000 years, however, the nature of the association between the hominid cranium and the ox teeth remains uncertain. The fossil is considered to be the most complete skull of that time period found in China.

text: The dating of the skull has been a subject of debate.

text: Uranium-series dating

text: of ox teeth from the site obtained a date of 209,000 ±23,000 years, however, the nature of the association between the hominid cranium and the ox teeth remains uncertain. The fossil is considered to be the most complete skull of that time period found in China.

answers: NDQ_005711

answers: Uranium

answers: NDQ_005712

answers: Uranium-series dating

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: uranium-series dating

answers: NDQ_005715

answers: NDQ_005716

answers: uranium

answers: NDQ_005717

answers: Uranium-series

answers: NDQ_005718

answers: uncertainty

answers: NDQ_005719

answers: no

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: Uranium-series

answers: NDQ_005712

answers: 209,000 <unk>23,000 years,

answers: NDQ_005713

answers: Uranium-series

answers: NDQ_005714

answers: Uranium-series

answers: NDQ_005715

answers: 209,000 <unk>23,000 years,

answers: NDQ_005716

answers: Uranium-series

answers: NDQ_005717

answers: 209,000 <unk>23,000 years,

answers: NDQ_005718

answers: uncertain.

answers: NDQ_005719

answers: Uranium-series

answers: NDQ_005720

answers: Uranium-series

text: State Senator John Sudam died on April 13, 1835; and State Senator John G. Stower resigned on September 29, 1835; leaving vacancies in the Second and Fifth District.

text: State Senator

text: John Sudam

text: died on April 13, 1835; and State Senator

text: John G. Stower

text: resigned on September 29, 1835; leaving vacancies in the Second and Fifth District.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: John Sudam died in 1835

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a noble gas

answers: NDQ_005715

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: John Sudam died on April 13, 1835

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: April 13, 1835;

answers: NDQ_005712

answers: 1835;

answers: NDQ_005713

answers: September 29, 1835;

answers: NDQ_005714

answers: April 13, 1835;

answers: NDQ_005715

answers: September 29, 1835;

answers: NDQ_005716

answers: April 13, 1835;

answers: NDQ_005717

answers: September 29, 1835;

answers: NDQ_005718

answers: vacancies in the Second and Fifth District.

answers: NDQ_005719

answers: September 29, 1835;

answers: NDQ_005720

answers: September 29, 1835;

text: Soil pollution can be caused by the following (non-exhaustive list!):

text: Soil pollution can be caused by the following (non-exhaustive list!):

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive elements are present

answers: NDQ_005713

answers: radioactive decay

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon dioxide

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: ionizing radiation

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: radioactive decay

answers: NDQ_005720

answers: no relevant information

answers: NDQ_005711

answers: following (non-exhaustive list!):

answers: NDQ_005712

answers: Soil pollution

answers: NDQ_005713

answers: Soil pollution

answers: NDQ_005714

answers: Soil pollution

answers: NDQ_005715

answers: Soil pollution can be caused by the following

answers: NDQ_005716

answers: Soil pollution

answers: NDQ_005717

answers: Soil pollution

answers: NDQ_005718

answers: Soil pollution

answers: NDQ_005719

answers: Soil pollution

answers: NDQ_005720

answers: Soil pollution

text: Canada won two diving medals at the 2000 Sydney Olympics — one silver and one bronze. Anne Montminy won the first ever platform diving medal for Canada.

text: Canada won two diving medals at the 2000 Sydney Olympics — one silver and one bronze.

text: Anne Montminy

text: won the first ever platform diving medal for Canada.

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radiometric dating is not reliable

answers: NDQ_005713

answers: no

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: how long does carbon-14 decay

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: How many medals did Canada win at the 2000 Sydney Olympics

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: are useful for very young materials

answers: NDQ_005720

answers: no

answers: NDQ_005711

answers: 2000 Sydney Olympics

answers: NDQ_005712

answers: 2000 Sydney Olympics — one silver and one bronze.

answers: NDQ_005713

answers: Anne Montminy won the first ever platform diving medal for Canada.

answers: NDQ_005714

answers: Canada won two diving medals at the 2000 Sydney Olympics

answers: NDQ_005715

answers: Anne Montminy won the first ever platform diving medal for Canada.

answers: NDQ_005716

answers: 2000 Sydney Olympics

answers: NDQ_005717

answers: 2000 Sydney Olympics

answers: NDQ_005718

answers: platform diving

answers: NDQ_005719

answers: 2000 Sydney Olympics

answers: NDQ_005720

answers: Canada won two diving medals at the 2000 Sydney Olympics

text: Original Air Date: 22 January 2015

text: Original Air Date: 22 January 2015

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive isotopes

answers: NDQ_005713

answers: radiometric dating uses the rate of decay of unstable isotopes

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: Carbon-14 decays to carbon-12 with a half-life

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: Original Air Date: 22 January 2015

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: They are useful for very young materials.

answers: NDQ_005720

answers: How old are zircon crystals?

answers: NDQ_005711

answers: Original Air Date: 22 January 2015

answers: NDQ_005712

answers: Original Air Date: 22 January 2015

answers: NDQ_005713

answers: 22 January 2015

answers: NDQ_005714

answers: 22 January 2015

answers: NDQ_005715

answers: 22 January 2015

answers: NDQ_005716

answers: 22 January 2015

answers: NDQ_005717

answers: 22 January 2015

answers: NDQ_005718

answers: context: Original Air Date: 22 January 2015

answers: NDQ_005719

answers: 22 January 2015

answers: NDQ_005720

answers: 22 January 2015

text: , represents the ratio of daughter to parent as used in standard radiometric dating.

text: , represents the ratio of daughter to parent as used in standard

text: radiometric dating

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay is not present

answers: NDQ_005713

answers: NDQ_005714

answers: carbon-14 is a stable isotope

answers: NDQ_005715

answers: half-lives

answers: NDQ_005716

answers: radioactive decay

answers: NDQ_005717

answers: the ratio of daughter to parent

answers: NDQ_005718

answers: non-reversible

answers: NDQ_005719

answers: ratio of daughter to parent

answers: NDQ_005720

answers: nuclei

answers: NDQ_005711

answers: ratio of daughter to parent

answers: NDQ_005712

answers: ratio of daughter to parent

answers: NDQ_005713

answers: ratio of daughter to parent

answers: NDQ_005714

answers: ratio of daughter to parent

answers: NDQ_005715

answers: ratio of daughter to parent as used in standard radiometric dating.

answers: NDQ_005716

answers: radiometric dating.

answers: NDQ_005717

answers: the ratio of daughter to parent

answers: NDQ_005718

answers: ratio of daughter to parent

answers: NDQ_005719

answers: radiometric dating.

answers: NDQ_005720

answers: ratio of daughter to parent as used in standard radiometric dating.

text: Original air date: 29 April 2001

text: Original air date: 29 April 2001

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: radioactive decay is not present

answers: NDQ_005713

answers: radiometric dating uses the rate of decay

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating

answers: NDQ_005717

answers: argon is the most common element

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: irradiation

answers: NDQ_005720

answers: uranium-lead

answers: NDQ_005711

answers: 29 April 2001

answers: NDQ_005712

answers: Original air date: 29 April 2001

answers: NDQ_005713

answers: 29 April 2001

answers: NDQ_005714

answers: 29 April 2001

answers: NDQ_005715

answers: 29 April 2001

answers: NDQ_005716

answers: 29 April 2001

answers: NDQ_005717

answers: 29 April 2001

answers: NDQ_005718

answers: context: Original air date: 29 April 2001

answers: NDQ_005719

answers: 29 April 2001

answers: NDQ_005720

answers: 29 April 2001

text: Date: 28 April 1979

text: Date: 28 April 1979

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: the material was made in 1979

answers: NDQ_005713

answers: 1979-04-28

answers: NDQ_005714

answers: carbon-14 is a radioactive element

answers: NDQ_005715

answers: carbon-14 decays to carbon-12

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: 28 April 1979

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: uranium-lead

answers: NDQ_005720

answers: on 28 April 1979

answers: NDQ_005711

answers: 28 April 1979

answers: NDQ_005712

answers: 28 April 1979

answers: NDQ_005713

answers: Date: 28 April 1979

answers: NDQ_005714

answers: 28 April 1979

answers: NDQ_005715

answers: 28 April 1979

answers: NDQ_005716

answers: 28 April 1979

answers: NDQ_005717

answers: 28 April 1979

answers: NDQ_005718

answers: Date: 28 April 1979

answers: NDQ_005719

answers: 28 April 1979

answers: NDQ_005720

answers: 28 April 1979

text: Japanese Release Date: 22 September 2011

text: Japanese Release Date: 22 September 2011

answers: NDQ_005711

answers: radioactive decay

answers: NDQ_005712

answers: 22 september 2011 is the release date

answers: NDQ_005713

answers: radiometric dating uses the rate of decay of unstable isotopes

answers: NDQ_005714

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005715

answers: 22 September 2011

answers: NDQ_005716

answers: carbon dating work

answers: NDQ_005717

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005718

answers: radioactive decay

answers: NDQ_005719

answers: uranium-lead

answers: NDQ_005720

answers: It was released on 22 September 2011

answers: NDQ_005711

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005712

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005713

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005714

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005715

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005716

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005717

answers: 22 September 2011

answers: NDQ_005718

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005719

answers: Japanese Release Date: 22 September 2011

answers: NDQ_005720

answers: 22 September 2011