A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica
Glaciovolcanic sequences are widespread in northern Victoria Land and their interpretation enables estimates of past ice thicknesses and other defining parameters of the coeval ice sheet to be made with considerable certainty. The terrestrial sequences are mainly Late Miocene in age (c. 12-5 Ma) and...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
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Online Access: | http://hdl.handle.net/11568/196263 https://doi.org/10.1016/j.palaeo.2011.05.008 https://www.sciencedirect.com/science/article/pii/S0031018211002537 |
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ftunivpisairis:oai:arpi.unipi.it:11568/196263 2024-04-21T07:52:07+00:00 A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica SMELLIE J. L. ROCCHI, SERGIO GEMELLI, MAURIZIO DI VINCENZO G. ARMIENTI, PIETRO Smellie, J. L. Rocchi, Sergio Gemelli, Maurizio DI VINCENZO, G. Armienti, Pietro 2011 STAMPA http://hdl.handle.net/11568/196263 https://doi.org/10.1016/j.palaeo.2011.05.008 https://www.sciencedirect.com/science/article/pii/S0031018211002537 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000293424300010 volume:307 issue:1-4 firstpage:129 lastpage:149 numberofpages:21 journal:PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY http://hdl.handle.net/11568/196263 doi:10.1016/j.palaeo.2011.05.008 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-79960428261 https://www.sciencedirect.com/science/article/pii/S0031018211002537 info:eu-repo/semantics/restrictedAccess info:eu-repo/semantics/article 2011 ftunivpisairis https://doi.org/10.1016/j.palaeo.2011.05.008 2024-03-28T01:33:48Z Glaciovolcanic sequences are widespread in northern Victoria Land and their interpretation enables estimates of past ice thicknesses and other defining parameters of the coeval ice sheet to be made with considerable certainty. The terrestrial sequences are mainly Late Miocene in age (c. 12-5 Ma) and conform to five main types: aa lava-fed deltas, volcanic sheet-like sequences, a glaciolacustrine sequence, scoria cones and tuff cones. Apart from the environmentally undiagnostic pyroclastic cones, the volcanic sequences were erupted in association with a glacial cover that was typically, and possibly never much more than, a few hundred metres thick (<300 m). Despite gaps in the record, no evidence was observed for prolonged subaerial (i.e. fully ice-free) eruptive conditions, suggesting either that ice-free conditions did not occur or else were of such limited areal extent or short duration that they left no record. These observations are consistent with the presence of a thin persistent Late Miocene ice dome or icefield draping the pre-Miocene topography in northern Victoria Land for the period, although it may have been confluent with the greater East Antarctic Ice Sheet similar to conditions present today. The presence of glacially emplaced sequences right down to present datum suggests that the Transantarctic Mountains in the region were already uplifted to their current elevation prior to the volcanism. The high terrain would have helped the ice sheet to establish and persist. The glacial thermal regime varied from wet-based and dynamic, to cold-based (frozen to its bed) and presumably relatively stable. A major transition from wet-based ice to cold-based ice might have occurred between 9.7 and 7.5 Ma consistent with published interpretations of the regional landscape evolution. Alternatively, the glacial thermal regime was dominantly polar since the earliest eruptions but with several temporary changes to a wet-based (sub-polar or temperate) more dynamic regime. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Victoria Land ARPI - Archivio della Ricerca dell'Università di Pisa Palaeogeography, Palaeoclimatology, Palaeoecology 307 1-4 129 149 |
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Open Polar |
collection |
ARPI - Archivio della Ricerca dell'Università di Pisa |
op_collection_id |
ftunivpisairis |
language |
English |
description |
Glaciovolcanic sequences are widespread in northern Victoria Land and their interpretation enables estimates of past ice thicknesses and other defining parameters of the coeval ice sheet to be made with considerable certainty. The terrestrial sequences are mainly Late Miocene in age (c. 12-5 Ma) and conform to five main types: aa lava-fed deltas, volcanic sheet-like sequences, a glaciolacustrine sequence, scoria cones and tuff cones. Apart from the environmentally undiagnostic pyroclastic cones, the volcanic sequences were erupted in association with a glacial cover that was typically, and possibly never much more than, a few hundred metres thick (<300 m). Despite gaps in the record, no evidence was observed for prolonged subaerial (i.e. fully ice-free) eruptive conditions, suggesting either that ice-free conditions did not occur or else were of such limited areal extent or short duration that they left no record. These observations are consistent with the presence of a thin persistent Late Miocene ice dome or icefield draping the pre-Miocene topography in northern Victoria Land for the period, although it may have been confluent with the greater East Antarctic Ice Sheet similar to conditions present today. The presence of glacially emplaced sequences right down to present datum suggests that the Transantarctic Mountains in the region were already uplifted to their current elevation prior to the volcanism. The high terrain would have helped the ice sheet to establish and persist. The glacial thermal regime varied from wet-based and dynamic, to cold-based (frozen to its bed) and presumably relatively stable. A major transition from wet-based ice to cold-based ice might have occurred between 9.7 and 7.5 Ma consistent with published interpretations of the regional landscape evolution. Alternatively, the glacial thermal regime was dominantly polar since the earliest eruptions but with several temporary changes to a wet-based (sub-polar or temperate) more dynamic regime. |
author2 |
Smellie, J. L. Rocchi, Sergio Gemelli, Maurizio DI VINCENZO, G. Armienti, Pietro |
format |
Article in Journal/Newspaper |
author |
SMELLIE J. L. ROCCHI, SERGIO GEMELLI, MAURIZIO DI VINCENZO G. ARMIENTI, PIETRO |
spellingShingle |
SMELLIE J. L. ROCCHI, SERGIO GEMELLI, MAURIZIO DI VINCENZO G. ARMIENTI, PIETRO A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica |
author_facet |
SMELLIE J. L. ROCCHI, SERGIO GEMELLI, MAURIZIO DI VINCENZO G. ARMIENTI, PIETRO |
author_sort |
SMELLIE J. L. |
title |
A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica |
title_short |
A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica |
title_full |
A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica |
title_fullStr |
A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica |
title_full_unstemmed |
A thin predominantly cold-based Late Miocene East Antarctic ice sheet inferred from glaciovolcanic sequences in northern Victoria Land, Antarctica |
title_sort |
thin predominantly cold-based late miocene east antarctic ice sheet inferred from glaciovolcanic sequences in northern victoria land, antarctica |
publishDate |
2011 |
url |
http://hdl.handle.net/11568/196263 https://doi.org/10.1016/j.palaeo.2011.05.008 https://www.sciencedirect.com/science/article/pii/S0031018211002537 |
genre |
Antarc* Antarctic Antarctica Ice Sheet Victoria Land |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Victoria Land |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000293424300010 volume:307 issue:1-4 firstpage:129 lastpage:149 numberofpages:21 journal:PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY http://hdl.handle.net/11568/196263 doi:10.1016/j.palaeo.2011.05.008 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-79960428261 https://www.sciencedirect.com/science/article/pii/S0031018211002537 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1016/j.palaeo.2011.05.008 |
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Palaeogeography, Palaeoclimatology, Palaeoecology |
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307 |
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1-4 |
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129 |
op_container_end_page |
149 |
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