New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea
It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in Eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Existing post-LGM ice retreat chronologies are considered suspect because nearly all have been d...
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ftlouisianastuir:oai:digitalcommons.lsu.edu:gradschool_theses-1943 2023-06-11T04:07:14+02:00 New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea Cone, Amy Noelle 2010-01-01T08:00:00Z application/pdf https://digitalcommons.lsu.edu/gradschool_theses/944 https://doi.org/10.31390/gradschool_theses.944 https://digitalcommons.lsu.edu/context/gradschool_theses/article/1943/viewcontent/uc.pdf unknown LSU Digital Commons https://digitalcommons.lsu.edu/gradschool_theses/944 doi:10.31390/gradschool_theses.944 https://digitalcommons.lsu.edu/context/gradschool_theses/article/1943/viewcontent/uc.pdf LSU Master's Theses Antarctica radiocarbon dating last glacial maximum ice retreat foraminifera Earth Sciences text 2010 ftlouisianastuir https://doi.org/10.31390/gradschool_theses.944 2023-05-28T18:59:04Z It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in Eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Existing post-LGM ice retreat chronologies are considered suspect because nearly all have been developed using radiocarbon dating of acid-insoluble organics (AIO). Foraminifer tests yield more accurate radiocarbon dates than AIO because unlike loose sediment, foram tests are unlikely to be contaminated by allochthonous carbon, but unfortunately forams are sparse in Antarctic marine sediment cores. Here I utilized a new 3-D multibeam survey of a mid-continental-shelf grounding zone wedge (GZW) and report four consistent radiocarbon dates of forams from four different depth intervals at two core sites on the foreset of the GZW in Eastern Basin, Ross Sea. The forams dated in this study most likely represent a mixture of in situ forams and forams reworked a short distance. These new radiocarbon dates are inconsistent with dates from Western Ross Sea and suggest that the WAIS began retreat across the Ross Sea Eastern Basin prior to 31,000 14C yr BP, more than 10,000 years earlier than previously thought. In the future, if in situ forams can be isolated from foreset sediments within other GZWs, precise dates for grounding event chronologies can be developed, which would ultimately permit us to relate the WAIS retreat to other high-resolution, proxy-based evidence of potential climatic and eustatic forcing. Text Antarc* Antarctic Antarctica Ice Sheet Ross Sea LSU Digital Commons (Louisiana State University) Antarctic Ross Sea West Antarctic Ice Sheet |
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Antarctica radiocarbon dating last glacial maximum ice retreat foraminifera Earth Sciences |
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Antarctica radiocarbon dating last glacial maximum ice retreat foraminifera Earth Sciences Cone, Amy Noelle New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea |
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Antarctica radiocarbon dating last glacial maximum ice retreat foraminifera Earth Sciences |
description |
It is widely accepted that the West Antarctic Ice Sheet (WAIS) was grounded at the continental shelf edge in Eastern Ross Sea during the Last Glacial Maximum (LGM), but the precise chronology is debated. Existing post-LGM ice retreat chronologies are considered suspect because nearly all have been developed using radiocarbon dating of acid-insoluble organics (AIO). Foraminifer tests yield more accurate radiocarbon dates than AIO because unlike loose sediment, foram tests are unlikely to be contaminated by allochthonous carbon, but unfortunately forams are sparse in Antarctic marine sediment cores. Here I utilized a new 3-D multibeam survey of a mid-continental-shelf grounding zone wedge (GZW) and report four consistent radiocarbon dates of forams from four different depth intervals at two core sites on the foreset of the GZW in Eastern Basin, Ross Sea. The forams dated in this study most likely represent a mixture of in situ forams and forams reworked a short distance. These new radiocarbon dates are inconsistent with dates from Western Ross Sea and suggest that the WAIS began retreat across the Ross Sea Eastern Basin prior to 31,000 14C yr BP, more than 10,000 years earlier than previously thought. In the future, if in situ forams can be isolated from foreset sediments within other GZWs, precise dates for grounding event chronologies can be developed, which would ultimately permit us to relate the WAIS retreat to other high-resolution, proxy-based evidence of potential climatic and eustatic forcing. |
format |
Text |
author |
Cone, Amy Noelle |
author_facet |
Cone, Amy Noelle |
author_sort |
Cone, Amy Noelle |
title |
New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea |
title_short |
New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea |
title_full |
New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea |
title_fullStr |
New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea |
title_full_unstemmed |
New age control on a mid-shelf grounding event in Eastern Basin, Ross Sea |
title_sort |
new age control on a mid-shelf grounding event in eastern basin, ross sea |
publisher |
LSU Digital Commons |
publishDate |
2010 |
url |
https://digitalcommons.lsu.edu/gradschool_theses/944 https://doi.org/10.31390/gradschool_theses.944 https://digitalcommons.lsu.edu/context/gradschool_theses/article/1943/viewcontent/uc.pdf |
geographic |
Antarctic Ross Sea West Antarctic Ice Sheet |
geographic_facet |
Antarctic Ross Sea West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Ross Sea |
op_source |
LSU Master's Theses |
op_relation |
https://digitalcommons.lsu.edu/gradschool_theses/944 doi:10.31390/gradschool_theses.944 https://digitalcommons.lsu.edu/context/gradschool_theses/article/1943/viewcontent/uc.pdf |
op_doi |
https://doi.org/10.31390/gradschool_theses.944 |
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1768380198309330944 |