A sea-level fingerprint of the Late Ordovician ice-sheet collapse
International audience The Hirnantian glacial acme (445–444 Ma) represents the glacial maximum of the long-lived Ordovician glaciation. The ensuing deglaciation and associated transgression deeply affected depositional environments and critically impacted marine living communities, con-tributing to...
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ftunivaixmarseil:oai:HAL:hal-02050736v1 2023-12-17T10:31:45+01:00 A sea-level fingerprint of the Late Ordovician ice-sheet collapse Pohl, A. Austermann, J. Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) 2018-05-30 https://hal.science/hal-02050736 en eng HAL CCSD Geological Society of America hal-02050736 https://hal.science/hal-02050736 ISSN: 0091-7613 EISSN: 1943-2682 Geology https://hal.science/hal-02050736 Geology, 2018, 46 (7), pp.595-598 [SDU]Sciences of the Universe [physics] info:eu-repo/semantics/article Journal articles 2018 ftunivaixmarseil 2023-11-21T23:47:50Z International audience The Hirnantian glacial acme (445–444 Ma) represents the glacial maximum of the long-lived Ordovician glaciation. The ensuing deglaciation and associated transgression deeply affected depositional environments and critically impacted marine living communities, con-tributing to the Late Ordovician Mass Extinction. In the absence of a better model, this transgressive event is usually considered to be a uniform (i.e., eustatic) rise in sea level, at least at low to intermediate paleolatitudes. This assumption may lead to erroneous interpretations of the geological record. Here we use a land-ice model and a gravita-tionally self-consistent treatment of sea-level change to propose the first numerical simulation of spatially varying late Hirnantian sea-level rise. We demonstrate significant departures from eustasy and compare our modeling results to key sedimentary sections. We show that previously enigmatic opposite sea-level trends (i.e., transgressive versus regressive) documented in the geological record are predicted by the model. Such sections may thus reflect patterns of sea-level change more complex than the eustatic approximation considered so far, rather than erroneous correlations. Our simulations also predict the locations where values of relative sea-level change are closest to the values predicted by a globally uniform rise and hence most rep-resentative of the volume of the ice sheet that collapsed. We identify these regions as preferential loci for future fieldwork investigating the ice volume during the Hirnantian glacial peak. Article in Journal/Newspaper Ice Sheet Aix-Marseille Université: HAL |
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Open Polar |
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Aix-Marseille Université: HAL |
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ftunivaixmarseil |
language |
English |
topic |
[SDU]Sciences of the Universe [physics] |
spellingShingle |
[SDU]Sciences of the Universe [physics] Pohl, A. Austermann, J. A sea-level fingerprint of the Late Ordovician ice-sheet collapse |
topic_facet |
[SDU]Sciences of the Universe [physics] |
description |
International audience The Hirnantian glacial acme (445–444 Ma) represents the glacial maximum of the long-lived Ordovician glaciation. The ensuing deglaciation and associated transgression deeply affected depositional environments and critically impacted marine living communities, con-tributing to the Late Ordovician Mass Extinction. In the absence of a better model, this transgressive event is usually considered to be a uniform (i.e., eustatic) rise in sea level, at least at low to intermediate paleolatitudes. This assumption may lead to erroneous interpretations of the geological record. Here we use a land-ice model and a gravita-tionally self-consistent treatment of sea-level change to propose the first numerical simulation of spatially varying late Hirnantian sea-level rise. We demonstrate significant departures from eustasy and compare our modeling results to key sedimentary sections. We show that previously enigmatic opposite sea-level trends (i.e., transgressive versus regressive) documented in the geological record are predicted by the model. Such sections may thus reflect patterns of sea-level change more complex than the eustatic approximation considered so far, rather than erroneous correlations. Our simulations also predict the locations where values of relative sea-level change are closest to the values predicted by a globally uniform rise and hence most rep-resentative of the volume of the ice sheet that collapsed. We identify these regions as preferential loci for future fieldwork investigating the ice volume during the Hirnantian glacial peak. |
author2 |
Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE) Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS) |
format |
Article in Journal/Newspaper |
author |
Pohl, A. Austermann, J. |
author_facet |
Pohl, A. Austermann, J. |
author_sort |
Pohl, A. |
title |
A sea-level fingerprint of the Late Ordovician ice-sheet collapse |
title_short |
A sea-level fingerprint of the Late Ordovician ice-sheet collapse |
title_full |
A sea-level fingerprint of the Late Ordovician ice-sheet collapse |
title_fullStr |
A sea-level fingerprint of the Late Ordovician ice-sheet collapse |
title_full_unstemmed |
A sea-level fingerprint of the Late Ordovician ice-sheet collapse |
title_sort |
sea-level fingerprint of the late ordovician ice-sheet collapse |
publisher |
HAL CCSD |
publishDate |
2018 |
url |
https://hal.science/hal-02050736 |
genre |
Ice Sheet |
genre_facet |
Ice Sheet |
op_source |
ISSN: 0091-7613 EISSN: 1943-2682 Geology https://hal.science/hal-02050736 Geology, 2018, 46 (7), pp.595-598 |
op_relation |
hal-02050736 https://hal.science/hal-02050736 |
_version_ |
1785585148660547584 |