Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements
We present a new in situ produced cosmogenic beryllium-10 and carbon-14 nuclide chronology from two sets (outer and inner) of alpine glacier moraines from the Grey Hunter massif of southern Yukon Territory, Canada. The chronology of moraines deposited by alpine glaciers outside the limits of the Las...
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ftdoajarticles:oai:doaj.org/article:2bc59300466645f6860c53383ef83b60 2024-09-15T18:08:00+00:00 Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements B. M. Goehring B. Menounos G. Osborn A. Hawkins B. Ward 2022-05-01T00:00:00Z https://doi.org/10.5194/gchron-4-311-2022 https://doaj.org/article/2bc59300466645f6860c53383ef83b60 EN eng Copernicus Publications https://gchron.copernicus.org/articles/4/311/2022/gchron-4-311-2022.pdf https://doaj.org/toc/2628-3719 doi:10.5194/gchron-4-311-2022 2628-3719 https://doaj.org/article/2bc59300466645f6860c53383ef83b60 Geochronology, Vol 4, Pp 311-322 (2022) Geology QE1-996.5 Stratigraphy QE640-699 article 2022 ftdoajarticles https://doi.org/10.5194/gchron-4-311-2022 2024-08-05T17:49:41Z We present a new in situ produced cosmogenic beryllium-10 and carbon-14 nuclide chronology from two sets (outer and inner) of alpine glacier moraines from the Grey Hunter massif of southern Yukon Territory, Canada. The chronology of moraines deposited by alpine glaciers outside the limits of the Last Glacial Maximum (LGM) ice sheets potentially provides a less-ambiguous archive of mass balance, and hence climate, than can be inferred from the extents of ice sheets themselves. Results for both nuclides are inconclusive for the outer moraines, with evidence for pre-LGM deposition (beryllium-10) and Holocene deposition (carbon-14). Beryllium-10 results from the inner moraine are suggestive of canonical LGM deposition but with relatively high scatter. Conversely, in situ carbon-14 results from the inner moraines are tightly clustered and suggestive of terminal Younger Dryas deposition. We explore plausible scenarios leading to the observed differences between nuclides and find that the most parsimonious explanation for the outer moraines is that of pre-LGM deposition, but many of the sampled boulder surfaces were not exhumed from within the moraine until the Holocene. Our results thus imply that the inner and outer moraines sampled pre- and post-date the canonical LGM and that moraines dating to the LGM are lacking likely due to overriding by the subsequent Late Glacial/earliest Holocene advance. Article in Journal/Newspaper glacier* Yukon Directory of Open Access Journals: DOAJ Articles Geochronology 4 1 311 322 |
institution |
Open Polar |
collection |
Directory of Open Access Journals: DOAJ Articles |
op_collection_id |
ftdoajarticles |
language |
English |
topic |
Geology QE1-996.5 Stratigraphy QE640-699 |
spellingShingle |
Geology QE1-996.5 Stratigraphy QE640-699 B. M. Goehring B. Menounos G. Osborn A. Hawkins B. Ward Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements |
topic_facet |
Geology QE1-996.5 Stratigraphy QE640-699 |
description |
We present a new in situ produced cosmogenic beryllium-10 and carbon-14 nuclide chronology from two sets (outer and inner) of alpine glacier moraines from the Grey Hunter massif of southern Yukon Territory, Canada. The chronology of moraines deposited by alpine glaciers outside the limits of the Last Glacial Maximum (LGM) ice sheets potentially provides a less-ambiguous archive of mass balance, and hence climate, than can be inferred from the extents of ice sheets themselves. Results for both nuclides are inconclusive for the outer moraines, with evidence for pre-LGM deposition (beryllium-10) and Holocene deposition (carbon-14). Beryllium-10 results from the inner moraine are suggestive of canonical LGM deposition but with relatively high scatter. Conversely, in situ carbon-14 results from the inner moraines are tightly clustered and suggestive of terminal Younger Dryas deposition. We explore plausible scenarios leading to the observed differences between nuclides and find that the most parsimonious explanation for the outer moraines is that of pre-LGM deposition, but many of the sampled boulder surfaces were not exhumed from within the moraine until the Holocene. Our results thus imply that the inner and outer moraines sampled pre- and post-date the canonical LGM and that moraines dating to the LGM are lacking likely due to overriding by the subsequent Late Glacial/earliest Holocene advance. |
format |
Article in Journal/Newspaper |
author |
B. M. Goehring B. Menounos G. Osborn A. Hawkins B. Ward |
author_facet |
B. M. Goehring B. Menounos G. Osborn A. Hawkins B. Ward |
author_sort |
B. M. Goehring |
title |
Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements |
title_short |
Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements |
title_full |
Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements |
title_fullStr |
Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements |
title_full_unstemmed |
Reconciling the apparent absence of a Last Glacial Maximum alpine glacial advance, Yukon Territory, Canada, through cosmogenic beryllium-10 and carbon-14 measurements |
title_sort |
reconciling the apparent absence of a last glacial maximum alpine glacial advance, yukon territory, canada, through cosmogenic beryllium-10 and carbon-14 measurements |
publisher |
Copernicus Publications |
publishDate |
2022 |
url |
https://doi.org/10.5194/gchron-4-311-2022 https://doaj.org/article/2bc59300466645f6860c53383ef83b60 |
genre |
glacier* Yukon |
genre_facet |
glacier* Yukon |
op_source |
Geochronology, Vol 4, Pp 311-322 (2022) |
op_relation |
https://gchron.copernicus.org/articles/4/311/2022/gchron-4-311-2022.pdf https://doaj.org/toc/2628-3719 doi:10.5194/gchron-4-311-2022 2628-3719 https://doaj.org/article/2bc59300466645f6860c53383ef83b60 |
op_doi |
https://doi.org/10.5194/gchron-4-311-2022 |
container_title |
Geochronology |
container_volume |
4 |
container_issue |
1 |
container_start_page |
311 |
op_container_end_page |
322 |
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1810445350436077568 |