Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska
Abstract Pleistocene glacial-estuarine sediment deposited in an intertidal environment of northeastern Bristol Bay, southwestern Alaska, was dated using a variety of approaches, including infrared stimulated and thermoluminescence (IRSL and TL) techniques. Analysis of modern and 14 C-dated Holocene...
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Cambridge University Press (CUP)
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crcambridgeupr:10.1006/qres.1996.0006 2024-06-09T07:46:12+00:00 Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska Kaufman, Darrell S. Forman, Steven L. Lea, Peter D. Wobus, Cameron W. 1996 http://dx.doi.org/10.1006/qres.1996.0006 http://api.elsevier.com/content/article/PII:S003358949690006X?httpAccept=text/xml http://api.elsevier.com/content/article/PII:S003358949690006X?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S003358940002456X en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Quaternary Research volume 45, issue 1, page 59-72 ISSN 0033-5894 1096-0287 journal-article 1996 crcambridgeupr https://doi.org/10.1006/qres.1996.0006 2024-05-15T13:13:57Z Abstract Pleistocene glacial-estuarine sediment deposited in an intertidal environment of northeastern Bristol Bay, southwestern Alaska, was dated using a variety of approaches, including infrared stimulated and thermoluminescence (IRSL and TL) techniques. Analysis of modern and 14 C-dated Holocene tide-flat mud demonstrates that the bulk of sediment in this environment is reset by solar radiation, thereby lending confidence to ages obtained from similar Pleistocene deposits by luminescence techniques. IRSL seems to be especially well suited for dating, with resolution on time scales of <10,000 yr. The ages of tide-flat mud of the Nushagak Formation, derived from the Ahklun Mountains to the northwest of Bristol Bay, and of Halfmoon Bay drift, derived from the Alaska Peninsula to the southeast, suggest contemporaneous glacial-estuarine deposition related to independent glacial source areas about 75,000–80,000 yr ago. This age is consistent with other geochronological data that indicate a pre-late-Wisconsin and post-substage-5e age, including nonfinite 14 C ages, a lack of interglacial indicators, and Old Crow tephra (∼140,000 yr) atop the drift, normal paleomagnetic inclinations, and amino acid (isoleucine) epimerization ratios (aIle/Ile). AIle/Ile ratios in Portlandia arctica (0.052 ± 0.003) from a marine-lag horizon at South Naknek beach, which separates Halfmoon Bay drift above from older glacial-estuarine drift below, are only slightly higher than in Mya truncata (0.041 ± 0.007) from last-interglacial Pelukian deposits at Nome. As laboratory heating experiments show that the two genera epimerize at similar rates, these data imply correlation of the marine lag at South Naknek beach with Pelukian deposits. Hence, glaciers on the Alaska Peninsula experienced major pre-late-Wisconsin advances both before and after the last interglaciation. Shells reworked into Halfmoon Bay drift yield aIle/Ile ratios of 0.028 ± 0.005 for Portlandia at Second Point and 0.027 ± 0.001 for Hiatella arctica at Etolin Point. ... Article in Journal/Newspaper glaciers Nome Alaska Cambridge University Press Quaternary Research 45 1 59 72 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
description |
Abstract Pleistocene glacial-estuarine sediment deposited in an intertidal environment of northeastern Bristol Bay, southwestern Alaska, was dated using a variety of approaches, including infrared stimulated and thermoluminescence (IRSL and TL) techniques. Analysis of modern and 14 C-dated Holocene tide-flat mud demonstrates that the bulk of sediment in this environment is reset by solar radiation, thereby lending confidence to ages obtained from similar Pleistocene deposits by luminescence techniques. IRSL seems to be especially well suited for dating, with resolution on time scales of <10,000 yr. The ages of tide-flat mud of the Nushagak Formation, derived from the Ahklun Mountains to the northwest of Bristol Bay, and of Halfmoon Bay drift, derived from the Alaska Peninsula to the southeast, suggest contemporaneous glacial-estuarine deposition related to independent glacial source areas about 75,000–80,000 yr ago. This age is consistent with other geochronological data that indicate a pre-late-Wisconsin and post-substage-5e age, including nonfinite 14 C ages, a lack of interglacial indicators, and Old Crow tephra (∼140,000 yr) atop the drift, normal paleomagnetic inclinations, and amino acid (isoleucine) epimerization ratios (aIle/Ile). AIle/Ile ratios in Portlandia arctica (0.052 ± 0.003) from a marine-lag horizon at South Naknek beach, which separates Halfmoon Bay drift above from older glacial-estuarine drift below, are only slightly higher than in Mya truncata (0.041 ± 0.007) from last-interglacial Pelukian deposits at Nome. As laboratory heating experiments show that the two genera epimerize at similar rates, these data imply correlation of the marine lag at South Naknek beach with Pelukian deposits. Hence, glaciers on the Alaska Peninsula experienced major pre-late-Wisconsin advances both before and after the last interglaciation. Shells reworked into Halfmoon Bay drift yield aIle/Ile ratios of 0.028 ± 0.005 for Portlandia at Second Point and 0.027 ± 0.001 for Hiatella arctica at Etolin Point. ... |
format |
Article in Journal/Newspaper |
author |
Kaufman, Darrell S. Forman, Steven L. Lea, Peter D. Wobus, Cameron W. |
spellingShingle |
Kaufman, Darrell S. Forman, Steven L. Lea, Peter D. Wobus, Cameron W. Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska |
author_facet |
Kaufman, Darrell S. Forman, Steven L. Lea, Peter D. Wobus, Cameron W. |
author_sort |
Kaufman, Darrell S. |
title |
Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska |
title_short |
Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska |
title_full |
Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska |
title_fullStr |
Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska |
title_full_unstemmed |
Age of Pre-late-Wisconsin Glacial-Estuarine Sedimentation, Bristol Bay, Alaska |
title_sort |
age of pre-late-wisconsin glacial-estuarine sedimentation, bristol bay, alaska |
publisher |
Cambridge University Press (CUP) |
publishDate |
1996 |
url |
http://dx.doi.org/10.1006/qres.1996.0006 http://api.elsevier.com/content/article/PII:S003358949690006X?httpAccept=text/xml http://api.elsevier.com/content/article/PII:S003358949690006X?httpAccept=text/plain https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S003358940002456X |
genre |
glaciers Nome Alaska |
genre_facet |
glaciers Nome Alaska |
op_source |
Quaternary Research volume 45, issue 1, page 59-72 ISSN 0033-5894 1096-0287 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1006/qres.1996.0006 |
container_title |
Quaternary Research |
container_volume |
45 |
container_issue |
1 |
container_start_page |
59 |
op_container_end_page |
72 |
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1801375946727489536 |