Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley
Investigations in Wright Valley, adjacent to the Transantarctic Mountains in East Antarctica, shed light on the question of whether high-latitude Pliocene climate was warm enough to cause widespread deglaciation of the East Antarctic craton with a concurrent Magellanic moorland-like environment. If...
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ftmaineuniv:oai:digitalcommons.library.umaine.edu:ers_facpub-1066 2023-05-15T13:33:49+02:00 Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley Hall, Brenda L. Denton, George H. Lux, Daniel R. Schlüchter, Christian 1997-05-01T07:00:00Z application/pdf https://digitalcommons.library.umaine.edu/ers_facpub/67 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1066&context=ers_facpub unknown DigitalCommons@UMaine https://digitalcommons.library.umaine.edu/ers_facpub/67 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1066&context=ers_facpub This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. In addition, no permission is required from the rights-holder(s) for educational uses. For other uses, you need to obtain permission from the rights-holder(s). Earth Science Faculty Scholarship Earth Sciences text 1997 ftmaineuniv 2023-03-12T18:49:12Z Investigations in Wright Valley, adjacent to the Transantarctic Mountains in East Antarctica, shed light on the question of whether high-latitude Pliocene climate was warm enough to cause widespread deglaciation of the East Antarctic craton with a concurrent Magellanic moorland-like environment. If Pliocene age diatoms, presently in glaciogenic deposits high in the Transantarctic Mountains, had come from seaways on the East Antarctic craton, an expanding Late Pliocene ice sheet must have first eroded them from marine sediments and then deposited the diatoms at their present high-altitude locations. This hypothetical expanding glacier would have had to have come through Wright Valley. Glacial drift sediments from the central Wright Valley were mapped, sampled, analyzed, and Ar-40/Ar-39 whole rock dated. Our evidence indicates that an East Antarctic outlet glacier has not expanded through Wright Valley, and hence cannot have overridden the Dry Valleys sector of the Transantarctic Mountains, any time in the past 3.8 myr. Rather, there was only moderate Pliocene expansion of local cola-based alpine glaciers and continuous cold-desert conditions in Wright Valley. Persistence of a cold-desert paleoenvironment implies that the sector of the East Antarctic Ice Sheet adjacent to Wright Valley has remained relatively stable without melting ablation zones since at least 3.8 Ma, in Early Pliocene time. A further implication is that Antarctic Ice Sheet behavior in the Pliocene was much like that in the Quaternary, when the ice sheet consisted of a stable, terrestrial core in East Antarctica and a dynamic, marine-based appendage in West Antarctica. Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica The University of Maine: DigitalCommons@UMaine Antarctic East Antarctica West Antarctica East Antarctic Ice Sheet Transantarctic Mountains Wright Valley ENVELOPE(161.833,161.833,-77.517,-77.517) |
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The University of Maine: DigitalCommons@UMaine |
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Earth Sciences |
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Earth Sciences Hall, Brenda L. Denton, George H. Lux, Daniel R. Schlüchter, Christian Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley |
topic_facet |
Earth Sciences |
description |
Investigations in Wright Valley, adjacent to the Transantarctic Mountains in East Antarctica, shed light on the question of whether high-latitude Pliocene climate was warm enough to cause widespread deglaciation of the East Antarctic craton with a concurrent Magellanic moorland-like environment. If Pliocene age diatoms, presently in glaciogenic deposits high in the Transantarctic Mountains, had come from seaways on the East Antarctic craton, an expanding Late Pliocene ice sheet must have first eroded them from marine sediments and then deposited the diatoms at their present high-altitude locations. This hypothetical expanding glacier would have had to have come through Wright Valley. Glacial drift sediments from the central Wright Valley were mapped, sampled, analyzed, and Ar-40/Ar-39 whole rock dated. Our evidence indicates that an East Antarctic outlet glacier has not expanded through Wright Valley, and hence cannot have overridden the Dry Valleys sector of the Transantarctic Mountains, any time in the past 3.8 myr. Rather, there was only moderate Pliocene expansion of local cola-based alpine glaciers and continuous cold-desert conditions in Wright Valley. Persistence of a cold-desert paleoenvironment implies that the sector of the East Antarctic Ice Sheet adjacent to Wright Valley has remained relatively stable without melting ablation zones since at least 3.8 Ma, in Early Pliocene time. A further implication is that Antarctic Ice Sheet behavior in the Pliocene was much like that in the Quaternary, when the ice sheet consisted of a stable, terrestrial core in East Antarctica and a dynamic, marine-based appendage in West Antarctica. |
format |
Text |
author |
Hall, Brenda L. Denton, George H. Lux, Daniel R. Schlüchter, Christian |
author_facet |
Hall, Brenda L. Denton, George H. Lux, Daniel R. Schlüchter, Christian |
author_sort |
Hall, Brenda L. |
title |
Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley |
title_short |
Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley |
title_full |
Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley |
title_fullStr |
Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley |
title_full_unstemmed |
Pliocene Paleoenvironment and Antarctic Ice Sheet Behavior: Evidence from Wright Valley |
title_sort |
pliocene paleoenvironment and antarctic ice sheet behavior: evidence from wright valley |
publisher |
DigitalCommons@UMaine |
publishDate |
1997 |
url |
https://digitalcommons.library.umaine.edu/ers_facpub/67 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1066&context=ers_facpub |
long_lat |
ENVELOPE(161.833,161.833,-77.517,-77.517) |
geographic |
Antarctic East Antarctica West Antarctica East Antarctic Ice Sheet Transantarctic Mountains Wright Valley |
geographic_facet |
Antarctic East Antarctica West Antarctica East Antarctic Ice Sheet Transantarctic Mountains Wright Valley |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet West Antarctica |
op_source |
Earth Science Faculty Scholarship |
op_relation |
https://digitalcommons.library.umaine.edu/ers_facpub/67 https://digitalcommons.library.umaine.edu/cgi/viewcontent.cgi?article=1066&context=ers_facpub |
op_rights |
This Item is protected by copyright and/or related rights. You are free to use this Item in any way that is permitted by the copyright and related rights legislation that applies to your use. In addition, no permission is required from the rights-holder(s) for educational uses. For other uses, you need to obtain permission from the rights-holder(s). |
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1766046358966370304 |