Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys
Summary Debate continues whether Antarctica has been in a stable deep freeze since the Miocene or experienced major fluctuations in climate and glacier extent though the Pliocene. A key question here is whether ashes are in situ and postdate their underlying deposits. There are at least three reason...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.534.978 2023-05-15T13:37:47+02:00 Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys Warren Dickinson John O. Stone The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534.978 http://geoinfo.nmt.edu/staff/dunbar/publications/documents/slettin_mann_mcintosh_dunbar_2007_isaes.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534.978 http://geoinfo.nmt.edu/staff/dunbar/publications/documents/slettin_mann_mcintosh_dunbar_2007_isaes.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://geoinfo.nmt.edu/staff/dunbar/publications/documents/slettin_mann_mcintosh_dunbar_2007_isaes.pdf text ftciteseerx 2016-01-08T10:46:42Z Summary Debate continues whether Antarctica has been in a stable deep freeze since the Miocene or experienced major fluctuations in climate and glacier extent though the Pliocene. A key question here is whether ashes are in situ and postdate their underlying deposits. There are at least three reasons suggesting that some of these ashes are reworked. First, we found blocks of glacially-transported ash in Beacon Valley. After disintegrating, these erratics leave localized deposits of relatively pure volcanic ash that is much older than the surfaces they overlie. Second, most surface-age estimates older than 2 Ma in the Dry Valleys are based on the eruption (Ar-Ar) ages of these reputed in situ tephras. In contrast, the majority of cosmogenic exposure ages are younger. Third, geomorphic and weathering processes are active today in Dry Valleys, indicating a younger landscape than Miocene age implied by the ancient Text Antarc* Antarctica Unknown Beacon Valley ENVELOPE(160.650,160.650,-77.817,-77.817) |
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ftciteseerx |
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English |
description |
Summary Debate continues whether Antarctica has been in a stable deep freeze since the Miocene or experienced major fluctuations in climate and glacier extent though the Pliocene. A key question here is whether ashes are in situ and postdate their underlying deposits. There are at least three reasons suggesting that some of these ashes are reworked. First, we found blocks of glacially-transported ash in Beacon Valley. After disintegrating, these erratics leave localized deposits of relatively pure volcanic ash that is much older than the surfaces they overlie. Second, most surface-age estimates older than 2 Ma in the Dry Valleys are based on the eruption (Ar-Ar) ages of these reputed in situ tephras. In contrast, the majority of cosmogenic exposure ages are younger. Third, geomorphic and weathering processes are active today in Dry Valleys, indicating a younger landscape than Miocene age implied by the ancient |
author2 |
The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
Warren Dickinson John O. Stone |
spellingShingle |
Warren Dickinson John O. Stone Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys |
author_facet |
Warren Dickinson John O. Stone |
author_sort |
Warren Dickinson |
title |
Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys |
title_short |
Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys |
title_full |
Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys |
title_fullStr |
Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys |
title_full_unstemmed |
Controversy continues over the geological history of the Dry Valleys. The “Stabilist ” school argues the Dry Valleys |
title_sort |
controversy continues over the geological history of the dry valleys. the “stabilist ” school argues the dry valleys |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534.978 http://geoinfo.nmt.edu/staff/dunbar/publications/documents/slettin_mann_mcintosh_dunbar_2007_isaes.pdf |
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ENVELOPE(160.650,160.650,-77.817,-77.817) |
geographic |
Beacon Valley |
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Beacon Valley |
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Antarc* Antarctica |
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Antarc* Antarctica |
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http://geoinfo.nmt.edu/staff/dunbar/publications/documents/slettin_mann_mcintosh_dunbar_2007_isaes.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.534.978 http://geoinfo.nmt.edu/staff/dunbar/publications/documents/slettin_mann_mcintosh_dunbar_2007_isaes.pdf |
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Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
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1766097736209268736 |