The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history
A paucity of data from the Antarctic continent has resulted in conflicting interpretations of Neogene Antarctic glacial history. Much of the debate centres on interpretations of the glacigene Sirius Group strata that crop out as discrete deposits along the length of the Transantarctic Mountains and...
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DigitalCommons@University of Nebraska - Lincoln
2002
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ftunivnebraskali:oai:digitalcommons.unl.edu:geosciencefacpub-1047 2023-11-12T04:03:50+01:00 The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history Wilson, G. A. Barron, J. A. Ashworth, A. C. Askin, R. A. Carter, J. A. Curren, M. G. Dalhuisen, D. H. Friedmann, E. I. Fyodorov-Davidov, D. G. Gilichinsky, D. A. Harper, M. A. Harwood, David M. Hiemstra, J. F. Janecek, T. R. Licht, K. J. Ostroumov, V. E. Powell, R. D. Rivkina, E. M. Rose, S. A. Stroeven, A. P. Stroeven, P. van der Meer, J. J. M. Wizevich, M. C. 2002-07-14T07:00:00Z application/pdf https://digitalcommons.unl.edu/geosciencefacpub/48 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1047/viewcontent/Harwood_PALAEO_2002_Mt_Feather__USGS.pdf unknown DigitalCommons@University of Nebraska - Lincoln https://digitalcommons.unl.edu/geosciencefacpub/48 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1047/viewcontent/Harwood_PALAEO_2002_Mt_Feather__USGS.pdf Papers in the Earth and Atmospheric Sciences Antarctica ice sheet Sirius Group climate coring microfossils Earth Sciences text 2002 ftunivnebraskali 2023-10-30T10:26:35Z A paucity of data from the Antarctic continent has resulted in conflicting interpretations of Neogene Antarctic glacial history. Much of the debate centres on interpretations of the glacigene Sirius Group strata that crop out as discrete deposits along the length of the Transantarctic Mountains and in particular on its age and the origin of the siliceous microfossils it encloses. Pliocene marine diatoms enclosed within Sirius Group strata are inferred to indicate a dynamic East Antarctic ice sheet that was much reduced, compared with today, in the early-middle Pliocene and then expanded again in the late Pliocene. However, the geomorphology of the Dry Valleys region is interpreted to represent a relatively long-lived (middle Miocene-recent) and stable polar climatic regime similar to that of today. The Mount Feather Diamicton infills a palaeovalley at ca. 2500 m on the NE flank of Mount Feather in the Dry Valleys region and has been included within the Sirius Group. We obtained four shallow cores (COMRAC 8, 9, 10 and 11) from beneath the permafrost boundary in the Mount Feather Diamicton in order to understand its origin and relationship with the surrounding landscape. Detailed studies of these cores (stratigraphy, sedimentology, palaeontology, micromorphology, petrography and fabric) have yielded new data that demonstrate a much more complex climatic and glacial history for the Mount Feather Diamicton than in previous interpretations. The data indicate that the Mount Feather Diamicton was deposited beneath a wet based glacier fed from a larger ice sheet behind the Transantarctic Mountains. It is, however, unlikely that this ice sheet overtopped Mount Feather (2985 m). A near-in situ non-marine diatom assemblage was recovered from 90 cm depth in COMRAC 10 and indicates a maximum depositional age of Late Miocene for the Mount Feather Diamicton. A subsequent glacial episode has distributed a boulder blanket across the surface of the diamicton. Other post-depositional processes include drying, infilling of surface ... Text Antarc* Antarctic Antarctica Ice Ice Sheet permafrost University of Nebraska-Lincoln: DigitalCommons@UNL Antarctic The Antarctic East Antarctic Ice Sheet Transantarctic Mountains Sirius ENVELOPE(163.250,163.250,-84.133,-84.133) Mount Feather ENVELOPE(160.350,160.350,-77.950,-77.950) |
institution |
Open Polar |
collection |
University of Nebraska-Lincoln: DigitalCommons@UNL |
op_collection_id |
ftunivnebraskali |
language |
unknown |
topic |
Antarctica ice sheet Sirius Group climate coring microfossils Earth Sciences |
spellingShingle |
Antarctica ice sheet Sirius Group climate coring microfossils Earth Sciences Wilson, G. A. Barron, J. A. Ashworth, A. C. Askin, R. A. Carter, J. A. Curren, M. G. Dalhuisen, D. H. Friedmann, E. I. Fyodorov-Davidov, D. G. Gilichinsky, D. A. Harper, M. A. Harwood, David M. Hiemstra, J. F. Janecek, T. R. Licht, K. J. Ostroumov, V. E. Powell, R. D. Rivkina, E. M. Rose, S. A. Stroeven, A. P. Stroeven, P. van der Meer, J. J. M. Wizevich, M. C. The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history |
topic_facet |
Antarctica ice sheet Sirius Group climate coring microfossils Earth Sciences |
description |
A paucity of data from the Antarctic continent has resulted in conflicting interpretations of Neogene Antarctic glacial history. Much of the debate centres on interpretations of the glacigene Sirius Group strata that crop out as discrete deposits along the length of the Transantarctic Mountains and in particular on its age and the origin of the siliceous microfossils it encloses. Pliocene marine diatoms enclosed within Sirius Group strata are inferred to indicate a dynamic East Antarctic ice sheet that was much reduced, compared with today, in the early-middle Pliocene and then expanded again in the late Pliocene. However, the geomorphology of the Dry Valleys region is interpreted to represent a relatively long-lived (middle Miocene-recent) and stable polar climatic regime similar to that of today. The Mount Feather Diamicton infills a palaeovalley at ca. 2500 m on the NE flank of Mount Feather in the Dry Valleys region and has been included within the Sirius Group. We obtained four shallow cores (COMRAC 8, 9, 10 and 11) from beneath the permafrost boundary in the Mount Feather Diamicton in order to understand its origin and relationship with the surrounding landscape. Detailed studies of these cores (stratigraphy, sedimentology, palaeontology, micromorphology, petrography and fabric) have yielded new data that demonstrate a much more complex climatic and glacial history for the Mount Feather Diamicton than in previous interpretations. The data indicate that the Mount Feather Diamicton was deposited beneath a wet based glacier fed from a larger ice sheet behind the Transantarctic Mountains. It is, however, unlikely that this ice sheet overtopped Mount Feather (2985 m). A near-in situ non-marine diatom assemblage was recovered from 90 cm depth in COMRAC 10 and indicates a maximum depositional age of Late Miocene for the Mount Feather Diamicton. A subsequent glacial episode has distributed a boulder blanket across the surface of the diamicton. Other post-depositional processes include drying, infilling of surface ... |
format |
Text |
author |
Wilson, G. A. Barron, J. A. Ashworth, A. C. Askin, R. A. Carter, J. A. Curren, M. G. Dalhuisen, D. H. Friedmann, E. I. Fyodorov-Davidov, D. G. Gilichinsky, D. A. Harper, M. A. Harwood, David M. Hiemstra, J. F. Janecek, T. R. Licht, K. J. Ostroumov, V. E. Powell, R. D. Rivkina, E. M. Rose, S. A. Stroeven, A. P. Stroeven, P. van der Meer, J. J. M. Wizevich, M. C. |
author_facet |
Wilson, G. A. Barron, J. A. Ashworth, A. C. Askin, R. A. Carter, J. A. Curren, M. G. Dalhuisen, D. H. Friedmann, E. I. Fyodorov-Davidov, D. G. Gilichinsky, D. A. Harper, M. A. Harwood, David M. Hiemstra, J. F. Janecek, T. R. Licht, K. J. Ostroumov, V. E. Powell, R. D. Rivkina, E. M. Rose, S. A. Stroeven, A. P. Stroeven, P. van der Meer, J. J. M. Wizevich, M. C. |
author_sort |
Wilson, G. A. |
title |
The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history |
title_short |
The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history |
title_full |
The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history |
title_fullStr |
The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history |
title_full_unstemmed |
The Mount Feather Diamicton of the Sirius Group: an accumulation of indicators of Neogene Antarctic glacial and climatic history |
title_sort |
mount feather diamicton of the sirius group: an accumulation of indicators of neogene antarctic glacial and climatic history |
publisher |
DigitalCommons@University of Nebraska - Lincoln |
publishDate |
2002 |
url |
https://digitalcommons.unl.edu/geosciencefacpub/48 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1047/viewcontent/Harwood_PALAEO_2002_Mt_Feather__USGS.pdf |
long_lat |
ENVELOPE(163.250,163.250,-84.133,-84.133) ENVELOPE(160.350,160.350,-77.950,-77.950) |
geographic |
Antarctic The Antarctic East Antarctic Ice Sheet Transantarctic Mountains Sirius Mount Feather |
geographic_facet |
Antarctic The Antarctic East Antarctic Ice Sheet Transantarctic Mountains Sirius Mount Feather |
genre |
Antarc* Antarctic Antarctica Ice Ice Sheet permafrost |
genre_facet |
Antarc* Antarctic Antarctica Ice Ice Sheet permafrost |
op_source |
Papers in the Earth and Atmospheric Sciences |
op_relation |
https://digitalcommons.unl.edu/geosciencefacpub/48 https://digitalcommons.unl.edu/context/geosciencefacpub/article/1047/viewcontent/Harwood_PALAEO_2002_Mt_Feather__USGS.pdf |
_version_ |
1782339246517911552 |