Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces
Abstract This paper describes measurements of concentrations of cosmogenic 26 Al, 10 Be and 21 Ne in quartz from bedrock surfaces in the Transantarctic Mountains where stratigraphic and geomorphic evidence shows that the surfaces were covered by ice in the past, but were not glacially eroded during...
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Online Access: | http://dx.doi.org/10.1017/s0954102014000261 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102014000261 |
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crcambridgeupr:10.1017/s0954102014000261 2024-05-12T07:56:51+00:00 Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces Balco, Greg Stone, John O.H. Sliwinski, Maciej G. Todd, Claire 2014 http://dx.doi.org/10.1017/s0954102014000261 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102014000261 en eng Cambridge University Press (CUP) http://creativecommons.org/licenses/by/3.0/ Antarctic Science volume 26, issue 6, page 708-723 ISSN 0954-1020 1365-2079 Geology Ecology, Evolution, Behavior and Systematics Oceanography journal-article 2014 crcambridgeupr https://doi.org/10.1017/s0954102014000261 2024-04-18T06:54:04Z Abstract This paper describes measurements of concentrations of cosmogenic 26 Al, 10 Be and 21 Ne in quartz from bedrock surfaces in the Transantarctic Mountains where stratigraphic and geomorphic evidence shows that the surfaces were covered by ice in the past, but were not glacially eroded during periods of ice cover. It then explores to what extent this information can be used to learn about past ice sheet change. First, cosmogenic nuclide concentrations in sandstone bedrock surfaces at two sites in the McMurdo Dry Valleys near 77°S are consistent with an equilibrium between nuclide production and loss by surface erosion and radioactive decay. They are most easily explained by a scenario in which: i) sites more than c . 100 m above the present ice surface were almost never ice-covered and eroded steadily at 0.5–1.5 m Ma -1 , and ii) sites near the present ice margin experienced similar erosion rates when ice-free, but have been covered by cold-based, non-erosive glacier ice as much as half of the time during the past several million years. Nuclide concentrations in granite bedrock at a site in the Quartz Hills near 85°S, on the other hand, have not reached production-erosion equilibrium, thus retaining evidence of the time they were first exposed to the cosmic ray flux. Nuclide concentrations at these sites are most easily explained by 4–6 Ma exposure, extremely low erosion rates of 5–10 cm Ma -1 during periods of exposure, and only very short periods of cold-based, non-erosive ice cover. Article in Journal/Newspaper Antarctic Science Ice Sheet McMurdo Dry Valleys Cambridge University Press McMurdo Dry Valleys Transantarctic Mountains Quartz Hills ENVELOPE(-132.833,-132.833,-85.933,-85.933) Antarctic Science 26 6 708 723 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Geology Ecology, Evolution, Behavior and Systematics Oceanography |
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Geology Ecology, Evolution, Behavior and Systematics Oceanography Balco, Greg Stone, John O.H. Sliwinski, Maciej G. Todd, Claire Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces |
topic_facet |
Geology Ecology, Evolution, Behavior and Systematics Oceanography |
description |
Abstract This paper describes measurements of concentrations of cosmogenic 26 Al, 10 Be and 21 Ne in quartz from bedrock surfaces in the Transantarctic Mountains where stratigraphic and geomorphic evidence shows that the surfaces were covered by ice in the past, but were not glacially eroded during periods of ice cover. It then explores to what extent this information can be used to learn about past ice sheet change. First, cosmogenic nuclide concentrations in sandstone bedrock surfaces at two sites in the McMurdo Dry Valleys near 77°S are consistent with an equilibrium between nuclide production and loss by surface erosion and radioactive decay. They are most easily explained by a scenario in which: i) sites more than c . 100 m above the present ice surface were almost never ice-covered and eroded steadily at 0.5–1.5 m Ma -1 , and ii) sites near the present ice margin experienced similar erosion rates when ice-free, but have been covered by cold-based, non-erosive glacier ice as much as half of the time during the past several million years. Nuclide concentrations in granite bedrock at a site in the Quartz Hills near 85°S, on the other hand, have not reached production-erosion equilibrium, thus retaining evidence of the time they were first exposed to the cosmic ray flux. Nuclide concentrations at these sites are most easily explained by 4–6 Ma exposure, extremely low erosion rates of 5–10 cm Ma -1 during periods of exposure, and only very short periods of cold-based, non-erosive ice cover. |
format |
Article in Journal/Newspaper |
author |
Balco, Greg Stone, John O.H. Sliwinski, Maciej G. Todd, Claire |
author_facet |
Balco, Greg Stone, John O.H. Sliwinski, Maciej G. Todd, Claire |
author_sort |
Balco, Greg |
title |
Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces |
title_short |
Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces |
title_full |
Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces |
title_fullStr |
Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces |
title_full_unstemmed |
Features of the glacial history of the Transantarctic Mountains inferred from cosmogenic 26 Al, 10 Be and 21 Ne concentrations in bedrock surfaces |
title_sort |
features of the glacial history of the transantarctic mountains inferred from cosmogenic 26 al, 10 be and 21 ne concentrations in bedrock surfaces |
publisher |
Cambridge University Press (CUP) |
publishDate |
2014 |
url |
http://dx.doi.org/10.1017/s0954102014000261 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0954102014000261 |
long_lat |
ENVELOPE(-132.833,-132.833,-85.933,-85.933) |
geographic |
McMurdo Dry Valleys Transantarctic Mountains Quartz Hills |
geographic_facet |
McMurdo Dry Valleys Transantarctic Mountains Quartz Hills |
genre |
Antarctic Science Ice Sheet McMurdo Dry Valleys |
genre_facet |
Antarctic Science Ice Sheet McMurdo Dry Valleys |
op_source |
Antarctic Science volume 26, issue 6, page 708-723 ISSN 0954-1020 1365-2079 |
op_rights |
http://creativecommons.org/licenses/by/3.0/ |
op_doi |
https://doi.org/10.1017/s0954102014000261 |
container_title |
Antarctic Science |
container_volume |
26 |
container_issue |
6 |
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708 |
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723 |
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1798837198291730432 |