Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka
The Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS...
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Online Access: | http://www.osti.gov/servlets/purl/1558872 https://www.osti.gov/biblio/1558872 https://doi.org/10.1017/qua.2019.10 |
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ftosti:oai:osti.gov:1558872 2023-07-30T04:04:11+02:00 Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka Margold, Martin Gosse, John C. Hidy, Alan J. Woywitka, Robin J. Young, Joseph M. Froese, Duane 2021-10-27 application/pdf http://www.osti.gov/servlets/purl/1558872 https://www.osti.gov/biblio/1558872 https://doi.org/10.1017/qua.2019.10 unknown http://www.osti.gov/servlets/purl/1558872 https://www.osti.gov/biblio/1558872 https://doi.org/10.1017/qua.2019.10 doi:10.1017/qua.2019.10 58 GEOSCIENCES 2021 ftosti https://doi.org/10.1017/qua.2019.10 2023-07-11T09:36:28Z The Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS) detached from the local ice masses of the Rocky Mountains, which initiated the opening of the southern end of the ice-free corridor between the Cordilleran Ice Sheet and the LIS. In this study, we use 10 Be exposure dating to constrain the beginning of this decoupling. Based on a group of 12 samples well-clustered in time, we date the detachment of the western LIS margin from the Rocky Mountain front to ~14.9 ± 0.9 ka. This is ~1000 years later than previously assumed, but a lack of a latitudinal trend in the ages over a distance of ~500 km is consistent with the rapid opening of a long wedge of unglaciated terrain portrayed in existing ice-retreat reconstructions. Finally, a later separation of the western LIS margin from the mountain front implies higher ice margin–retreat rates in order to meet the Younger Dryas ice margin position near the boundary of the Canadian Shield ~2000 years later. Other/Unknown Material Ice Sheet SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) Canada Rocky Mountain Foothills ENVELOPE(-123.003,-123.003,56.500,56.500) Quaternary Research 92 2 469 482 |
institution |
Open Polar |
collection |
SciTec Connect (Office of Scientific and Technical Information - OSTI, U.S. Department of Energy) |
op_collection_id |
ftosti |
language |
unknown |
topic |
58 GEOSCIENCES |
spellingShingle |
58 GEOSCIENCES Margold, Martin Gosse, John C. Hidy, Alan J. Woywitka, Robin J. Young, Joseph M. Froese, Duane Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka |
topic_facet |
58 GEOSCIENCES |
description |
The Foothills Erratics Train consists of large quartzite blocks of Rocky Mountains origin deposited on the eastern slopes of the Rocky Mountain Foothills in Alberta between ~53.5°N and 49°N. The blocks were deposited in their present locations when the western margin of the Laurentide Ice Sheet (LIS) detached from the local ice masses of the Rocky Mountains, which initiated the opening of the southern end of the ice-free corridor between the Cordilleran Ice Sheet and the LIS. In this study, we use 10 Be exposure dating to constrain the beginning of this decoupling. Based on a group of 12 samples well-clustered in time, we date the detachment of the western LIS margin from the Rocky Mountain front to ~14.9 ± 0.9 ka. This is ~1000 years later than previously assumed, but a lack of a latitudinal trend in the ages over a distance of ~500 km is consistent with the rapid opening of a long wedge of unglaciated terrain portrayed in existing ice-retreat reconstructions. Finally, a later separation of the western LIS margin from the mountain front implies higher ice margin–retreat rates in order to meet the Younger Dryas ice margin position near the boundary of the Canadian Shield ~2000 years later. |
author |
Margold, Martin Gosse, John C. Hidy, Alan J. Woywitka, Robin J. Young, Joseph M. Froese, Duane |
author_facet |
Margold, Martin Gosse, John C. Hidy, Alan J. Woywitka, Robin J. Young, Joseph M. Froese, Duane |
author_sort |
Margold, Martin |
title |
Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka |
title_short |
Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka |
title_full |
Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka |
title_fullStr |
Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka |
title_full_unstemmed |
Beryllium-10 dating of the Foothills Erratics Train in Alberta, Canada, indicates detachment of the Laurentide Ice Sheet from the Rocky Mountains at ~15 ka |
title_sort |
beryllium-10 dating of the foothills erratics train in alberta, canada, indicates detachment of the laurentide ice sheet from the rocky mountains at ~15 ka |
publishDate |
2021 |
url |
http://www.osti.gov/servlets/purl/1558872 https://www.osti.gov/biblio/1558872 https://doi.org/10.1017/qua.2019.10 |
long_lat |
ENVELOPE(-123.003,-123.003,56.500,56.500) |
geographic |
Canada Rocky Mountain Foothills |
geographic_facet |
Canada Rocky Mountain Foothills |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_relation |
http://www.osti.gov/servlets/purl/1558872 https://www.osti.gov/biblio/1558872 https://doi.org/10.1017/qua.2019.10 doi:10.1017/qua.2019.10 |
op_doi |
https://doi.org/10.1017/qua.2019.10 |
container_title |
Quaternary Research |
container_volume |
92 |
container_issue |
2 |
container_start_page |
469 |
op_container_end_page |
482 |
_version_ |
1772815435376361472 |