Retreat of the Smith Sound Ice Stream in the Early Holocene
Nares Strait, a major connection between the Arctic Ocean and Baffin Bay, was blocked by coalescent Innuitian and Greenland ice sheets during the last glaciation. This paper focuses on the events and processes leading to the opening of the strait and the environmental response to establishment of th...
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crwiley:10.1111/bor.12391 2024-09-15T17:54:13+00:00 Retreat of the Smith Sound Ice Stream in the Early Holocene Jennings, Anne E. Andrews, John T. Oliver, Brett Walczak, Maureen Mix, Alan National Science Foundation 2019 http://dx.doi.org/10.1111/bor.12391 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12391 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12391 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12391 https://onlinelibrary.wiley.com/doi/am-pdf/10.1111/bor.12391 en eng Wiley http://onlinelibrary.wiley.com/termsAndConditions#am http://onlinelibrary.wiley.com/termsAndConditions#vor Boreas volume 48, issue 4, page 825-840 ISSN 0300-9483 1502-3885 journal-article 2019 crwiley https://doi.org/10.1111/bor.12391 2024-07-18T04:21:59Z Nares Strait, a major connection between the Arctic Ocean and Baffin Bay, was blocked by coalescent Innuitian and Greenland ice sheets during the last glaciation. This paper focuses on the events and processes leading to the opening of the strait and the environmental response to establishment of the Arctic‐Atlantic throughflow. The study is based on sedimentological, mineralogical and foraminiferal analyses of radiocarbon‐dated cores 2001 LSSL ‐0014 PC and TC from northern Baffin Bay. Radiocarbon dates on benthic foraminifera were calibrated with ΔR = 220±20 years. Basal compact pebbly mud is interpreted as a subglacial deposit formed by glacial overriding of unconsolidated marine sediments. It is overlain by ice‐proximal (red/grey laminated, ice‐proximal glaciomarine unit barren of foraminifera and containing >2 mm clasts interpreted as ice‐rafted debris) to ice‐distal (calcareous, grey pebbly mud with foraminifera indicative of a stratified water column with chilled Atlantic Water fauna and species associated with perennial and then seasonal sea ice cover) glacial marine sediment units. The age model indicates ice retreat into Smith Sound as early as c. 11.7 and as late as c. 11.2 cal. ka BP followed by progressively more distal glaciomarine conditions as the ice margin retreated toward the Kennedy Channel. We hypothesize that a distinct IRD layer deposited between 9.3 and 9 (9.4–8.9 1σ) cal. ka BP marks the break‐up of ice in Kennedy Channel resulting in the opening of Nares Strait as an Arctic‐Atlantic throughflow. Overlying foraminiferal assemblages indicate enhanced marine productivity consistent with entry of nutrient‐rich Arctic Surface Water. A pronounced rise in agglutinated foraminifers and sand‐sized diatoms, and loss of detrital calcite characterize the uppermost bioturbated mud, which was deposited after 4.8 (3.67–5.55 1σ) cal. ka BP . The timing of the transition is poorly resolved as it coincides with the slow sedimentation rates that ensued after the ice margins retreated onto land. Article in Journal/Newspaper Arctic Ocean Baffin Bay Baffin Bay Baffin Foraminifera* Greenland Kennedy channel Nares strait Sea ice Smith sound Wiley Online Library Boreas 48 4 825 840 |
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Wiley Online Library |
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crwiley |
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English |
description |
Nares Strait, a major connection between the Arctic Ocean and Baffin Bay, was blocked by coalescent Innuitian and Greenland ice sheets during the last glaciation. This paper focuses on the events and processes leading to the opening of the strait and the environmental response to establishment of the Arctic‐Atlantic throughflow. The study is based on sedimentological, mineralogical and foraminiferal analyses of radiocarbon‐dated cores 2001 LSSL ‐0014 PC and TC from northern Baffin Bay. Radiocarbon dates on benthic foraminifera were calibrated with ΔR = 220±20 years. Basal compact pebbly mud is interpreted as a subglacial deposit formed by glacial overriding of unconsolidated marine sediments. It is overlain by ice‐proximal (red/grey laminated, ice‐proximal glaciomarine unit barren of foraminifera and containing >2 mm clasts interpreted as ice‐rafted debris) to ice‐distal (calcareous, grey pebbly mud with foraminifera indicative of a stratified water column with chilled Atlantic Water fauna and species associated with perennial and then seasonal sea ice cover) glacial marine sediment units. The age model indicates ice retreat into Smith Sound as early as c. 11.7 and as late as c. 11.2 cal. ka BP followed by progressively more distal glaciomarine conditions as the ice margin retreated toward the Kennedy Channel. We hypothesize that a distinct IRD layer deposited between 9.3 and 9 (9.4–8.9 1σ) cal. ka BP marks the break‐up of ice in Kennedy Channel resulting in the opening of Nares Strait as an Arctic‐Atlantic throughflow. Overlying foraminiferal assemblages indicate enhanced marine productivity consistent with entry of nutrient‐rich Arctic Surface Water. A pronounced rise in agglutinated foraminifers and sand‐sized diatoms, and loss of detrital calcite characterize the uppermost bioturbated mud, which was deposited after 4.8 (3.67–5.55 1σ) cal. ka BP . The timing of the transition is poorly resolved as it coincides with the slow sedimentation rates that ensued after the ice margins retreated onto land. |
author2 |
National Science Foundation |
format |
Article in Journal/Newspaper |
author |
Jennings, Anne E. Andrews, John T. Oliver, Brett Walczak, Maureen Mix, Alan |
spellingShingle |
Jennings, Anne E. Andrews, John T. Oliver, Brett Walczak, Maureen Mix, Alan Retreat of the Smith Sound Ice Stream in the Early Holocene |
author_facet |
Jennings, Anne E. Andrews, John T. Oliver, Brett Walczak, Maureen Mix, Alan |
author_sort |
Jennings, Anne E. |
title |
Retreat of the Smith Sound Ice Stream in the Early Holocene |
title_short |
Retreat of the Smith Sound Ice Stream in the Early Holocene |
title_full |
Retreat of the Smith Sound Ice Stream in the Early Holocene |
title_fullStr |
Retreat of the Smith Sound Ice Stream in the Early Holocene |
title_full_unstemmed |
Retreat of the Smith Sound Ice Stream in the Early Holocene |
title_sort |
retreat of the smith sound ice stream in the early holocene |
publisher |
Wiley |
publishDate |
2019 |
url |
http://dx.doi.org/10.1111/bor.12391 https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1111%2Fbor.12391 https://onlinelibrary.wiley.com/doi/pdf/10.1111/bor.12391 https://onlinelibrary.wiley.com/doi/full-xml/10.1111/bor.12391 https://onlinelibrary.wiley.com/doi/am-pdf/10.1111/bor.12391 |
genre |
Arctic Ocean Baffin Bay Baffin Bay Baffin Foraminifera* Greenland Kennedy channel Nares strait Sea ice Smith sound |
genre_facet |
Arctic Ocean Baffin Bay Baffin Bay Baffin Foraminifera* Greenland Kennedy channel Nares strait Sea ice Smith sound |
op_source |
Boreas volume 48, issue 4, page 825-840 ISSN 0300-9483 1502-3885 |
op_rights |
http://onlinelibrary.wiley.com/termsAndConditions#am http://onlinelibrary.wiley.com/termsAndConditions#vor |
op_doi |
https://doi.org/10.1111/bor.12391 |
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Boreas |
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48 |
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825 |
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840 |
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