Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment
Cores acquired by the ANDRILL McMurdo Ice Shelf Project (AND-1B) provide the basis for a new sedimentation model for glacimarine depositional sequences that reflect cyclic glacial-interglacial fluctuations of a marine-based ice sheet in the western Ross Embayment over the past 2.0Ma. Notwithstanding...
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Online Access: | http://hdl.handle.net/11365/20912 https://doi.org/10.1016/j.quascirev.2011.12.012 |
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ftunivsiena:oai:usiena-air.unisi.it:11365/20912 2024-04-14T08:01:44+00:00 Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment McKay, Robert Naish, Tim Powell, Ross Barrett, Peter Scherer, Reed Talarico, Franco Philip Kyle Monien, Donata Kuhn, Gerhard Jackolski, Chris Williams, Trevor Mckay, Robert Naish, Tim Powell, Ro Barrett, Peter Scherer, Reed Talarico, Franco Philip, Kyle Monien, Donata Kuhn, Gerhard Jackolski, Chri Williams, Trevor 2012 STAMPA http://hdl.handle.net/11365/20912 https://doi.org/10.1016/j.quascirev.2011.12.012 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000301826100008 volume:34 firstpage:93 lastpage:112 numberofpages:20 journal:QUATERNARY SCIENCE REVIEWS http://hdl.handle.net/11365/20912 doi:10.1016/j.quascirev.2011.12.012 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84856606050 info:eu-repo/semantics/closedAccess Palaeoclimatology Pleistocene Sequence stratigraphy West Antarctic Ice Sheet info:eu-repo/semantics/article 2012 ftunivsiena https://doi.org/10.1016/j.quascirev.2011.12.012 2024-03-21T15:56:46Z Cores acquired by the ANDRILL McMurdo Ice Shelf Project (AND-1B) provide the basis for a new sedimentation model for glacimarine depositional sequences that reflect cyclic glacial-interglacial fluctuations of a marine-based ice sheet in the western Ross Embayment over the past 2.0Ma. Notwithstanding periodic erosion during advances of the ice sheet, uncertainties inherent to the sedimentological interpretation, and a limited number of chronological datums, it is clear that subglacial to grounding-zone sedimentation was dominant at the AND-1B site during the Late Pleistocene with interglacials being represented only by thin intervals of ice-shelf sediment. Each sequence is characterised by subglacial, massive diamictite that pass upwards into glacimarine diamictites and mudstones. This provides the first direct evidence that the marine-based Antarctic Ice Sheet has oscillated between a grounded and floating state at least 7times in the Ross Embayment over the last 780ka, implying a Milankovitch orbital influence. An unconformity in AND-1B, that spans most (~200kyr) of the Mid-Pleistocene Transition is inferred to represent widespread expansion of a marine-based ice sheet in the Ross Embayment at 0.8Ma. Prior to 1.0Ma, interglacial periods are characterised by open-water conditions at the drill site with high abundances of volcanoclastic deposits and occasional diatomaceous sediments. These may have responded to precession (~20-kyr) or obliquity (~40-kyr) orbital control. The occurrence of 6.7m of phonolitic glass reworked from Mt Erebus in interglacial deposits beneath Last Glacial Maximum till requires open ocean or ice shelf conditions in the western Ross Sea around the drill site within the past 250ka and implies a Ross Ice Shelf similar to or less extensive than today during Marine Isotope Stage 7 or 5. © 2011 Elsevier Ltd. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet Ice Shelf McMurdo Ice Shelf Ross Ice Shelf Ross Sea Università degli Studi di Siena: USiena air Antarctic McMurdo Ice Shelf ENVELOPE(166.500,166.500,-78.000,-78.000) Ross Ice Shelf Ross Sea West Antarctic Ice Sheet Quaternary Science Reviews 34 93 112 |
institution |
Open Polar |
collection |
Università degli Studi di Siena: USiena air |
op_collection_id |
ftunivsiena |
language |
English |
topic |
Palaeoclimatology Pleistocene Sequence stratigraphy West Antarctic Ice Sheet |
spellingShingle |
Palaeoclimatology Pleistocene Sequence stratigraphy West Antarctic Ice Sheet McKay, Robert Naish, Tim Powell, Ross Barrett, Peter Scherer, Reed Talarico, Franco Philip Kyle Monien, Donata Kuhn, Gerhard Jackolski, Chris Williams, Trevor Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment |
topic_facet |
Palaeoclimatology Pleistocene Sequence stratigraphy West Antarctic Ice Sheet |
description |
Cores acquired by the ANDRILL McMurdo Ice Shelf Project (AND-1B) provide the basis for a new sedimentation model for glacimarine depositional sequences that reflect cyclic glacial-interglacial fluctuations of a marine-based ice sheet in the western Ross Embayment over the past 2.0Ma. Notwithstanding periodic erosion during advances of the ice sheet, uncertainties inherent to the sedimentological interpretation, and a limited number of chronological datums, it is clear that subglacial to grounding-zone sedimentation was dominant at the AND-1B site during the Late Pleistocene with interglacials being represented only by thin intervals of ice-shelf sediment. Each sequence is characterised by subglacial, massive diamictite that pass upwards into glacimarine diamictites and mudstones. This provides the first direct evidence that the marine-based Antarctic Ice Sheet has oscillated between a grounded and floating state at least 7times in the Ross Embayment over the last 780ka, implying a Milankovitch orbital influence. An unconformity in AND-1B, that spans most (~200kyr) of the Mid-Pleistocene Transition is inferred to represent widespread expansion of a marine-based ice sheet in the Ross Embayment at 0.8Ma. Prior to 1.0Ma, interglacial periods are characterised by open-water conditions at the drill site with high abundances of volcanoclastic deposits and occasional diatomaceous sediments. These may have responded to precession (~20-kyr) or obliquity (~40-kyr) orbital control. The occurrence of 6.7m of phonolitic glass reworked from Mt Erebus in interglacial deposits beneath Last Glacial Maximum till requires open ocean or ice shelf conditions in the western Ross Sea around the drill site within the past 250ka and implies a Ross Ice Shelf similar to or less extensive than today during Marine Isotope Stage 7 or 5. © 2011 Elsevier Ltd. |
author2 |
Mckay, Robert Naish, Tim Powell, Ro Barrett, Peter Scherer, Reed Talarico, Franco Philip, Kyle Monien, Donata Kuhn, Gerhard Jackolski, Chri Williams, Trevor |
format |
Article in Journal/Newspaper |
author |
McKay, Robert Naish, Tim Powell, Ross Barrett, Peter Scherer, Reed Talarico, Franco Philip Kyle Monien, Donata Kuhn, Gerhard Jackolski, Chris Williams, Trevor |
author_facet |
McKay, Robert Naish, Tim Powell, Ross Barrett, Peter Scherer, Reed Talarico, Franco Philip Kyle Monien, Donata Kuhn, Gerhard Jackolski, Chris Williams, Trevor |
author_sort |
McKay, Robert |
title |
Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment |
title_short |
Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment |
title_full |
Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment |
title_fullStr |
Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment |
title_full_unstemmed |
Pleistocene variability of Antarctic Ice Sheet extent in the Ross Embayment |
title_sort |
pleistocene variability of antarctic ice sheet extent in the ross embayment |
publishDate |
2012 |
url |
http://hdl.handle.net/11365/20912 https://doi.org/10.1016/j.quascirev.2011.12.012 |
long_lat |
ENVELOPE(166.500,166.500,-78.000,-78.000) |
geographic |
Antarctic McMurdo Ice Shelf Ross Ice Shelf Ross Sea West Antarctic Ice Sheet |
geographic_facet |
Antarctic McMurdo Ice Shelf Ross Ice Shelf Ross Sea West Antarctic Ice Sheet |
genre |
Antarc* Antarctic Ice Sheet Ice Shelf McMurdo Ice Shelf Ross Ice Shelf Ross Sea |
genre_facet |
Antarc* Antarctic Ice Sheet Ice Shelf McMurdo Ice Shelf Ross Ice Shelf Ross Sea |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000301826100008 volume:34 firstpage:93 lastpage:112 numberofpages:20 journal:QUATERNARY SCIENCE REVIEWS http://hdl.handle.net/11365/20912 doi:10.1016/j.quascirev.2011.12.012 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84856606050 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1016/j.quascirev.2011.12.012 |
container_title |
Quaternary Science Reviews |
container_volume |
34 |
container_start_page |
93 |
op_container_end_page |
112 |
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1796310566897188864 |