The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating
Beacon Valley, Antarctica, contains unique remnants of glacier ice underneath a till layer covering the valley floor. To constrain the age and evolution of this important indicator of Antarctic paleoclimate, we analyzed two dolerite erratics from the till surface and one from within the ice for cosm...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.549.5173 2023-05-15T13:34:25+02:00 The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating Jo«rg M. Scha«fer A Heinrich Baur A George H. Denton B Susan Ivy-ochs C Dave R. Marchant D Christian Schlu«chter C Rainer Wieler A The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.5173 http://people.bu.edu/marchant/Dave_FullText_Papers/Schafer_EPSL_2000.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.5173 http://people.bu.edu/marchant/Dave_FullText_Papers/Schafer_EPSL_2000.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://people.bu.edu/marchant/Dave_FullText_Papers/Schafer_EPSL_2000.pdf cosmogenic elements noble gases relict materials ice sublimation Antarctica text ftciteseerx 2016-01-08T11:26:49Z Beacon Valley, Antarctica, contains unique remnants of glacier ice underneath a till layer covering the valley floor. To constrain the age and evolution of this important indicator of Antarctic paleoclimate, we analyzed two dolerite erratics from the till surface and one from within the ice for cosmogenic helium and neon. A conservative minimum exposure age of the older surface sample is 2.3 Ma, but taking into account erosion, the true exposure age of this boulder is likely to be considerably higher. The buried sample contains more than 20 times less cosmogenic noble gases than the old surface sample, although its current shielding would imply only a three times lower production rate. This indicates that the ice level has slowly been lowered by sublimation at the rate of a few m/Ma. The high exposure age of the surface sample as well as the very low sublimation rate of the relict ice both support the conclusion that the remnant ice in Beacon Valley was deposited many million years ago [Sugden et al., Nature 376 (1995) 412^414] and has never been thinner than at present. In addition, we found that cosmogenic helium and neon are released quantitatively from Text Antarc* Antarctic Antarctica Unknown Antarctic Beacon Valley ENVELOPE(160.650,160.650,-77.817,-77.817) |
institution |
Open Polar |
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op_collection_id |
ftciteseerx |
language |
English |
topic |
cosmogenic elements noble gases relict materials ice sublimation Antarctica |
spellingShingle |
cosmogenic elements noble gases relict materials ice sublimation Antarctica Jo«rg M. Scha«fer A Heinrich Baur A George H. Denton B Susan Ivy-ochs C Dave R. Marchant D Christian Schlu«chter C Rainer Wieler A The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating |
topic_facet |
cosmogenic elements noble gases relict materials ice sublimation Antarctica |
description |
Beacon Valley, Antarctica, contains unique remnants of glacier ice underneath a till layer covering the valley floor. To constrain the age and evolution of this important indicator of Antarctic paleoclimate, we analyzed two dolerite erratics from the till surface and one from within the ice for cosmogenic helium and neon. A conservative minimum exposure age of the older surface sample is 2.3 Ma, but taking into account erosion, the true exposure age of this boulder is likely to be considerably higher. The buried sample contains more than 20 times less cosmogenic noble gases than the old surface sample, although its current shielding would imply only a three times lower production rate. This indicates that the ice level has slowly been lowered by sublimation at the rate of a few m/Ma. The high exposure age of the surface sample as well as the very low sublimation rate of the relict ice both support the conclusion that the remnant ice in Beacon Valley was deposited many million years ago [Sugden et al., Nature 376 (1995) 412^414] and has never been thinner than at present. In addition, we found that cosmogenic helium and neon are released quantitatively from |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Jo«rg M. Scha«fer A Heinrich Baur A George H. Denton B Susan Ivy-ochs C Dave R. Marchant D Christian Schlu«chter C Rainer Wieler A |
author_facet |
Jo«rg M. Scha«fer A Heinrich Baur A George H. Denton B Susan Ivy-ochs C Dave R. Marchant D Christian Schlu«chter C Rainer Wieler A |
author_sort |
Jo«rg M. Scha«fer A |
title |
The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating |
title_short |
The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating |
title_full |
The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating |
title_fullStr |
The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating |
title_full_unstemmed |
The oldest ice on Earth in Beacon Valley, Antarctica: new evidence from surface exposure dating |
title_sort |
oldest ice on earth in beacon valley, antarctica: new evidence from surface exposure dating |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.5173 http://people.bu.edu/marchant/Dave_FullText_Papers/Schafer_EPSL_2000.pdf |
long_lat |
ENVELOPE(160.650,160.650,-77.817,-77.817) |
geographic |
Antarctic Beacon Valley |
geographic_facet |
Antarctic Beacon Valley |
genre |
Antarc* Antarctic Antarctica |
genre_facet |
Antarc* Antarctic Antarctica |
op_source |
http://people.bu.edu/marchant/Dave_FullText_Papers/Schafer_EPSL_2000.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.549.5173 http://people.bu.edu/marchant/Dave_FullText_Papers/Schafer_EPSL_2000.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766052614396444672 |