Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history
We use cosmogenic 26Al/10Be ratios in rocks from the Shackleton Range, Antarctica to investigate geological scatter, a challenge that faces exposure-age studies in Antarctica. Examining the scatter helps reveal the long-term lowering of Slessor Glacier, an outlet glacier of the East Antarctic Ice Sh...
Published in: | Quaternary Geochronology |
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2014
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Online Access: | http://hdl.handle.net/1959.4/unsworks_37177 https://doi.org/10.1016/j.quageo.2013.03.008 |
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ftunswworks:oai:unsworks.library.unsw.edu.au:1959.4/unsworks_37177 2024-06-02T07:56:41+00:00 Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history Hein, AS Fogwill, CJ Sugden, DE Xu, S 2014-02-01 http://hdl.handle.net/1959.4/unsworks_37177 https://doi.org/10.1016/j.quageo.2013.03.008 unknown Elsevier http://purl.org/au-research/grants/arc/LP120200724 http://purl.org/au-research/grants/arc/FT120100004 http://hdl.handle.net/1959.4/unsworks_37177 https://doi.org/10.1016/j.quageo.2013.03.008 metadata only access http://purl.org/coar/access_right/c_14cb CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ urn:ISSN:1871-1014 urn:ISSN:1878-0350 Quaternary Geochronology, 19, 52-66 13 Climate Action anzsrc-for: 0402 Geochemistry anzsrc-for: 0403 Geology anzsrc-for: 0406 Physical Geography and Environmental Geoscience journal article http://purl.org/coar/resource_type/c_6501 2014 ftunswworks https://doi.org/10.1016/j.quageo.2013.03.008 2024-05-07T23:59:50Z We use cosmogenic 26Al/10Be ratios in rocks from the Shackleton Range, Antarctica to investigate geological scatter, a challenge that faces exposure-age studies in Antarctica. Examining the scatter helps reveal the long-term lowering of Slessor Glacier, an outlet glacier of the East Antarctic Ice Sheet (EAIS) which flows into the Weddell Sea embayment. 144 26Al and 10Be exposure ages from 72 samples are related to bedrock or clast sample characteristics and geomorphological measures of weathering, slope and stability. We explore this noisy dataset by using Principal Components Analysis (PCA) to identify patterns in the data. Despite noise, there exist correlations between age and degree of weathering and age and elevation above the adjacent ice surface. Clasts with young exposure ages have more complex exposure histories than those with old exposure ages. In terms of glacial history we show that (a) warm-based ice covered the upper slopes of the Shackleton Range millions of years ago and that the uplands have been mainly free of ice for more than 800ka, (b) that Slessor Glacier's surface elevation was c. 150m above present at c. 270ka and c. 700ka. © 2013. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Slessor Glacier Weddell Sea UNSW Sydney (The University of New South Wales): UNSWorks Antarctic Weddell Sea East Antarctic Ice Sheet Shackleton Weddell Shackleton Range ENVELOPE(-26.000,-26.000,-80.833,-80.833) Slessor ENVELOPE(-64.967,-64.967,-66.517,-66.517) Slessor Glacier ENVELOPE(-26.000,-26.000,-79.833,-79.833) Quaternary Geochronology 19 52 66 |
institution |
Open Polar |
collection |
UNSW Sydney (The University of New South Wales): UNSWorks |
op_collection_id |
ftunswworks |
language |
unknown |
topic |
13 Climate Action anzsrc-for: 0402 Geochemistry anzsrc-for: 0403 Geology anzsrc-for: 0406 Physical Geography and Environmental Geoscience |
spellingShingle |
13 Climate Action anzsrc-for: 0402 Geochemistry anzsrc-for: 0403 Geology anzsrc-for: 0406 Physical Geography and Environmental Geoscience Hein, AS Fogwill, CJ Sugden, DE Xu, S Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history |
topic_facet |
13 Climate Action anzsrc-for: 0402 Geochemistry anzsrc-for: 0403 Geology anzsrc-for: 0406 Physical Geography and Environmental Geoscience |
description |
We use cosmogenic 26Al/10Be ratios in rocks from the Shackleton Range, Antarctica to investigate geological scatter, a challenge that faces exposure-age studies in Antarctica. Examining the scatter helps reveal the long-term lowering of Slessor Glacier, an outlet glacier of the East Antarctic Ice Sheet (EAIS) which flows into the Weddell Sea embayment. 144 26Al and 10Be exposure ages from 72 samples are related to bedrock or clast sample characteristics and geomorphological measures of weathering, slope and stability. We explore this noisy dataset by using Principal Components Analysis (PCA) to identify patterns in the data. Despite noise, there exist correlations between age and degree of weathering and age and elevation above the adjacent ice surface. Clasts with young exposure ages have more complex exposure histories than those with old exposure ages. In terms of glacial history we show that (a) warm-based ice covered the upper slopes of the Shackleton Range millions of years ago and that the uplands have been mainly free of ice for more than 800ka, (b) that Slessor Glacier's surface elevation was c. 150m above present at c. 270ka and c. 700ka. © 2013. |
format |
Article in Journal/Newspaper |
author |
Hein, AS Fogwill, CJ Sugden, DE Xu, S |
author_facet |
Hein, AS Fogwill, CJ Sugden, DE Xu, S |
author_sort |
Hein, AS |
title |
Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history |
title_short |
Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history |
title_full |
Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history |
title_fullStr |
Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history |
title_full_unstemmed |
Geological scatter of cosmogenic-nuclide exposure ages in the Shackleton Range, Antarctica: Implications for glacial history |
title_sort |
geological scatter of cosmogenic-nuclide exposure ages in the shackleton range, antarctica: implications for glacial history |
publisher |
Elsevier |
publishDate |
2014 |
url |
http://hdl.handle.net/1959.4/unsworks_37177 https://doi.org/10.1016/j.quageo.2013.03.008 |
long_lat |
ENVELOPE(-26.000,-26.000,-80.833,-80.833) ENVELOPE(-64.967,-64.967,-66.517,-66.517) ENVELOPE(-26.000,-26.000,-79.833,-79.833) |
geographic |
Antarctic Weddell Sea East Antarctic Ice Sheet Shackleton Weddell Shackleton Range Slessor Slessor Glacier |
geographic_facet |
Antarctic Weddell Sea East Antarctic Ice Sheet Shackleton Weddell Shackleton Range Slessor Slessor Glacier |
genre |
Antarc* Antarctic Antarctica Ice Sheet Slessor Glacier Weddell Sea |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Slessor Glacier Weddell Sea |
op_source |
urn:ISSN:1871-1014 urn:ISSN:1878-0350 Quaternary Geochronology, 19, 52-66 |
op_relation |
http://purl.org/au-research/grants/arc/LP120200724 http://purl.org/au-research/grants/arc/FT120100004 http://hdl.handle.net/1959.4/unsworks_37177 https://doi.org/10.1016/j.quageo.2013.03.008 |
op_rights |
metadata only access http://purl.org/coar/access_right/c_14cb CC-BY-NC-ND https://creativecommons.org/licenses/by-nc-nd/4.0/ |
op_doi |
https://doi.org/10.1016/j.quageo.2013.03.008 |
container_title |
Quaternary Geochronology |
container_volume |
19 |
container_start_page |
52 |
op_container_end_page |
66 |
_version_ |
1800758072017158144 |