Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition
The East Antarctic ice sheet underwent a major expansion during the Mid-Miocene Climate Transition, around 14 Ma, lowering sea level by ∼60 m. However, direct or indirect evidence of where changes in the ice sheet occurred is limited. Here we present new insights on timing and locations of ice sheet...
Published in: | Earth and Planetary Science Letters |
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Montclair State University Digital Commons
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ftmontclairstuni:oai:digitalcommons.montclair.edu:earth-environ-studies-facpubs-1281 2023-07-23T04:15:52+02:00 Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition Pierce, Elizabeth L. van de Flierdt, Tina Williams, Trevor Hemming, Sidney R. Cook, Carys P. Passchier, Sandra 2017-11-15T08:00:00Z https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/282 https://doi.org/10.1016/j.epsl.2017.08.011 unknown Montclair State University Digital Commons https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/282 doi:10.1016/j.epsl.2017.08.011 Department of Earth and Environmental Studies Faculty Scholarship and Creative Works Ar/ Ar thermochronology East Antarctic ice sheet IODP Wilkes Subglacial Basin detrital provenance mid-Miocene climate transition text 2017 ftmontclairstuni https://doi.org/10.1016/j.epsl.2017.08.011 2023-07-03T21:48:21Z The East Antarctic ice sheet underwent a major expansion during the Mid-Miocene Climate Transition, around 14 Ma, lowering sea level by ∼60 m. However, direct or indirect evidence of where changes in the ice sheet occurred is limited. Here we present new insights on timing and locations of ice sheet change from two drill sites offshore East Antarctica. IODP Site U1356, Wilkes Land, and ODP Site 1165, Prydz Bay are located adjacent to two major ice drainage areas, the Wilkes Subglacial Basin and the Lambert Graben. Ice-rafted detritus (IRD), including dropstones, was deposited in concentrations far exceeding those known in the rest of the Miocene succession at both sites between 14.1 and 13.8 Ma, indicating that large amounts of IRD-bearing icebergs were calved from independent drainage basins during this relatively short interval. At Site U1356, the IRD was delivered in distinct pulses, suggesting that the overall ice advance was punctuated by short periods of ice retreat in the Wilkes Subglacial Basin. Provenance analysis of the mid-Miocene IRD and fine-grained sediments provides additional insights on the movement of the ice margin and subglacial geology. At Site U1356, the dominant 40 Ar/ 39 Ar thermochronological age of the ice-rafted hornblende grains is 1400–1550 Ma, differing from the majority of recent IRD in the area, from which we infer an inland source area of this thermochronological age extending along the eastern part of the Adélie Craton, which forms the western side of the Wilkes Subglacial Basin. Neodymium isotopic compositions from the terrigenous fine fraction at Site U1356 imply that the ice margin periodically expanded from high ground well into the Wilkes Subglacial Basin during periods of MMCT ice growth. At Site 1165, MMCT pebble-sized IRD are sourced from both the local Lambert Graben and the distant Aurora Subglacial Basin drainage area. Together, the occurrence and provenance of the IRD and glacially-eroded sediment at these two marine drill sites proximal to the Antarctic continent ... Text Antarc* Antarctic Antarctica East Antarctica Ice Sheet Iceberg* Prydz Bay Wilkes Land Montclair State University Digital Commons Antarctic The Antarctic East Antarctica Prydz Bay East Antarctic Ice Sheet Wilkes Land ENVELOPE(120.000,120.000,-69.000,-69.000) Wilkes Subglacial Basin ENVELOPE(145.000,145.000,-75.000,-75.000) Earth and Planetary Science Letters 478 1 13 |
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Open Polar |
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Montclair State University Digital Commons |
op_collection_id |
ftmontclairstuni |
language |
unknown |
topic |
Ar/ Ar thermochronology East Antarctic ice sheet IODP Wilkes Subglacial Basin detrital provenance mid-Miocene climate transition |
spellingShingle |
Ar/ Ar thermochronology East Antarctic ice sheet IODP Wilkes Subglacial Basin detrital provenance mid-Miocene climate transition Pierce, Elizabeth L. van de Flierdt, Tina Williams, Trevor Hemming, Sidney R. Cook, Carys P. Passchier, Sandra Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition |
topic_facet |
Ar/ Ar thermochronology East Antarctic ice sheet IODP Wilkes Subglacial Basin detrital provenance mid-Miocene climate transition |
description |
The East Antarctic ice sheet underwent a major expansion during the Mid-Miocene Climate Transition, around 14 Ma, lowering sea level by ∼60 m. However, direct or indirect evidence of where changes in the ice sheet occurred is limited. Here we present new insights on timing and locations of ice sheet change from two drill sites offshore East Antarctica. IODP Site U1356, Wilkes Land, and ODP Site 1165, Prydz Bay are located adjacent to two major ice drainage areas, the Wilkes Subglacial Basin and the Lambert Graben. Ice-rafted detritus (IRD), including dropstones, was deposited in concentrations far exceeding those known in the rest of the Miocene succession at both sites between 14.1 and 13.8 Ma, indicating that large amounts of IRD-bearing icebergs were calved from independent drainage basins during this relatively short interval. At Site U1356, the IRD was delivered in distinct pulses, suggesting that the overall ice advance was punctuated by short periods of ice retreat in the Wilkes Subglacial Basin. Provenance analysis of the mid-Miocene IRD and fine-grained sediments provides additional insights on the movement of the ice margin and subglacial geology. At Site U1356, the dominant 40 Ar/ 39 Ar thermochronological age of the ice-rafted hornblende grains is 1400–1550 Ma, differing from the majority of recent IRD in the area, from which we infer an inland source area of this thermochronological age extending along the eastern part of the Adélie Craton, which forms the western side of the Wilkes Subglacial Basin. Neodymium isotopic compositions from the terrigenous fine fraction at Site U1356 imply that the ice margin periodically expanded from high ground well into the Wilkes Subglacial Basin during periods of MMCT ice growth. At Site 1165, MMCT pebble-sized IRD are sourced from both the local Lambert Graben and the distant Aurora Subglacial Basin drainage area. Together, the occurrence and provenance of the IRD and glacially-eroded sediment at these two marine drill sites proximal to the Antarctic continent ... |
format |
Text |
author |
Pierce, Elizabeth L. van de Flierdt, Tina Williams, Trevor Hemming, Sidney R. Cook, Carys P. Passchier, Sandra |
author_facet |
Pierce, Elizabeth L. van de Flierdt, Tina Williams, Trevor Hemming, Sidney R. Cook, Carys P. Passchier, Sandra |
author_sort |
Pierce, Elizabeth L. |
title |
Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition |
title_short |
Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition |
title_full |
Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition |
title_fullStr |
Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition |
title_full_unstemmed |
Evidence for a Dynamic East Antarctic Ice Sheet During the Mid-Miocene Climate Transition |
title_sort |
evidence for a dynamic east antarctic ice sheet during the mid-miocene climate transition |
publisher |
Montclair State University Digital Commons |
publishDate |
2017 |
url |
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/282 https://doi.org/10.1016/j.epsl.2017.08.011 |
long_lat |
ENVELOPE(120.000,120.000,-69.000,-69.000) ENVELOPE(145.000,145.000,-75.000,-75.000) |
geographic |
Antarctic The Antarctic East Antarctica Prydz Bay East Antarctic Ice Sheet Wilkes Land Wilkes Subglacial Basin |
geographic_facet |
Antarctic The Antarctic East Antarctica Prydz Bay East Antarctic Ice Sheet Wilkes Land Wilkes Subglacial Basin |
genre |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Iceberg* Prydz Bay Wilkes Land |
genre_facet |
Antarc* Antarctic Antarctica East Antarctica Ice Sheet Iceberg* Prydz Bay Wilkes Land |
op_source |
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works |
op_relation |
https://digitalcommons.montclair.edu/earth-environ-studies-facpubs/282 doi:10.1016/j.epsl.2017.08.011 |
op_doi |
https://doi.org/10.1016/j.epsl.2017.08.011 |
container_title |
Earth and Planetary Science Letters |
container_volume |
478 |
container_start_page |
1 |
op_container_end_page |
13 |
_version_ |
1772177010081136640 |