Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra
Abstract Application of the glass fission-track dating method to Chester Bluff tephra (CBt), exposed in loess deposits at Chester Bluff along the Yukon River in east-central Alaska, has clarified the age of the immediately underlying fossiliferous interglacial bed. Surprise Creek tephra (SZt), at si...
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Language: | English |
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Cambridge University Press (CUP)
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Online Access: | http://dx.doi.org/10.1017/qua.2017.30 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589417000308 |
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crcambridgeupr:10.1017/qua.2017.30 2024-06-23T07:55:56+00:00 Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra Westgate, John A. Pearce, Nicholas J.G. 2017 http://dx.doi.org/10.1017/qua.2017.30 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589417000308 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 88, issue 1, page 152-159 ISSN 0033-5894 1096-0287 journal-article 2017 crcambridgeupr https://doi.org/10.1017/qua.2017.30 2024-06-05T04:05:00Z Abstract Application of the glass fission-track dating method to Chester Bluff tephra (CBt), exposed in loess deposits at Chester Bluff along the Yukon River in east-central Alaska, has clarified the age of the immediately underlying fossiliferous interglacial bed. Surprise Creek tephra (SZt), at site CRH47 in the northern Old Crow basin of the Yukon Territory, is a correlative of CBt so that the new age information on CBt can also be applied to the interglacial sediments below SZt. Two independent age determinations were obtained on CBt, 243±28 ka and 249±26 ka, giving a weighted mean age and error of 246±19 ka. Therefore, the closely associated interglacial bed belongs to the early part of Marine Oxygen Isotope Stage (MIS) 7. The stratigraphy and paleoenvironmental setting of SZt show that deposition of the tephra occurred soon after interglacial conditions, when the climate became colder, probably between MIS 7.5 and 7.4, that is, slightly younger than the mean fission-track age, but within the 1σ uncertainty. This result tightly constrains the age of the rich mammalian faunal assemblage found at and just below SZt at the CRH47 site. Article in Journal/Newspaper Old Crow Yukon river Alaska Beringia Yukon Cambridge University Press Yukon Quaternary Research 88 1 152 159 |
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Cambridge University Press |
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English |
description |
Abstract Application of the glass fission-track dating method to Chester Bluff tephra (CBt), exposed in loess deposits at Chester Bluff along the Yukon River in east-central Alaska, has clarified the age of the immediately underlying fossiliferous interglacial bed. Surprise Creek tephra (SZt), at site CRH47 in the northern Old Crow basin of the Yukon Territory, is a correlative of CBt so that the new age information on CBt can also be applied to the interglacial sediments below SZt. Two independent age determinations were obtained on CBt, 243±28 ka and 249±26 ka, giving a weighted mean age and error of 246±19 ka. Therefore, the closely associated interglacial bed belongs to the early part of Marine Oxygen Isotope Stage (MIS) 7. The stratigraphy and paleoenvironmental setting of SZt show that deposition of the tephra occurred soon after interglacial conditions, when the climate became colder, probably between MIS 7.5 and 7.4, that is, slightly younger than the mean fission-track age, but within the 1σ uncertainty. This result tightly constrains the age of the rich mammalian faunal assemblage found at and just below SZt at the CRH47 site. |
format |
Article in Journal/Newspaper |
author |
Westgate, John A. Pearce, Nicholas J.G. |
spellingShingle |
Westgate, John A. Pearce, Nicholas J.G. Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra |
author_facet |
Westgate, John A. Pearce, Nicholas J.G. |
author_sort |
Westgate, John A. |
title |
Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra |
title_short |
Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra |
title_full |
Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra |
title_fullStr |
Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra |
title_full_unstemmed |
Age of some Pleistocene interglacial beds and associated fossils in eastern Beringia defined by fission tracks in glass shards of Chester Bluff tephra |
title_sort |
age of some pleistocene interglacial beds and associated fossils in eastern beringia defined by fission tracks in glass shards of chester bluff tephra |
publisher |
Cambridge University Press (CUP) |
publishDate |
2017 |
url |
http://dx.doi.org/10.1017/qua.2017.30 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0033589417000308 |
geographic |
Yukon |
geographic_facet |
Yukon |
genre |
Old Crow Yukon river Alaska Beringia Yukon |
genre_facet |
Old Crow Yukon river Alaska Beringia Yukon |
op_source |
Quaternary Research volume 88, issue 1, page 152-159 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/qua.2017.30 |
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Quaternary Research |
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88 |
container_issue |
1 |
container_start_page |
152 |
op_container_end_page |
159 |
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1802648737266270208 |