Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France)
The Eocene–Oligocene Transition (EOT) marks the onset of the Antarctic glaciation and the switch from greenhouse to icehouse climates. However, the driving mechanisms and the precise timing of the EOT remain controversial mostly due to the lack of well-dated stratigraphic records, especially in cont...
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Copernicus Publications
2021
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fttriple:oai:gotriple.eu:oai:doaj.org/article:14ac1be47d144f7096009dbf3312b097 2023-05-15T13:42:08+02:00 Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) S. Boulila G. Dupont-Nivet B. Galbrun H. Bauer J.-J. Châteauneuf 2021-11-01 https://doi.org/10.5194/cp-17-2343-2021 https://cp.copernicus.org/articles/17/2343/2021/cp-17-2343-2021.pdf https://doaj.org/article/14ac1be47d144f7096009dbf3312b097 en eng Copernicus Publications doi:10.5194/cp-17-2343-2021 1814-9324 1814-9332 https://cp.copernicus.org/articles/17/2343/2021/cp-17-2343-2021.pdf https://doaj.org/article/14ac1be47d144f7096009dbf3312b097 undefined Climate of the Past, Vol 17, Pp 2343-2360 (2021) geo envir Journal Article https://vocabularies.coar-repositories.org/resource_types/c_6501/ 2021 fttriple https://doi.org/10.5194/cp-17-2343-2021 2023-01-22T19:13:45Z The Eocene–Oligocene Transition (EOT) marks the onset of the Antarctic glaciation and the switch from greenhouse to icehouse climates. However, the driving mechanisms and the precise timing of the EOT remain controversial mostly due to the lack of well-dated stratigraphic records, especially in continental environments. Here we present a cyclo-magnetostratigraphic and sedimentological study of a ∼ 7.6 Myr long lacustrine record spanning the late Eocene to the earliest Oligocene, from a drill core in the Rennes Basin (France). Cyclostratigraphic analysis of natural gamma radiation (NGR) log data yields duration estimates of Chrons C12r through C16n.1n, providing additional constraints on the Eocene timescale. Correlations between the orbital eccentricity curve and the 405 kyr tuned NGR time series indicate that 33.71 and 34.10 Ma are the most likely proposed ages of the EO boundary. Additionally, the 405 kyr tuning calibrates the most pronounced NGR cyclicity to a period of ∼1 Myr, matching the g1–g5 eccentricity term, supporting its significant expression in continental depositional environments, and hypothesizing that the paleolake level may have behaved as a low-pass filter for orbital forcing. Two prominent changes in the sedimentary facies were detected across the EOT, which are temporally equivalent to the two main climatic steps, EOT-1 and Oi-1. We suggest that these two facies changes reflect the two major Antarctic cooling/glacial phases via the hydrological cycle, as significant shifts to drier and cooler climate conditions. Finally, the interval spanning the EOT precursor glacial event through EOT-1 is remarkably dominated by obliquity. This suggests preconditioning of the major Antarctic glaciation, either from obliquity directly affecting the formation/(in)stability of the incipient Antarctic Ice Sheet (AIS), or through obliquity modulation of the North Atlantic Deep Water production. Article in Journal/Newspaper Antarc* Antarctic Ice Sheet North Atlantic Deep Water North Atlantic Unknown Antarctic The Antarctic Climate of the Past 17 6 2343 2360 |
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language |
English |
topic |
geo envir |
spellingShingle |
geo envir S. Boulila G. Dupont-Nivet B. Galbrun H. Bauer J.-J. Châteauneuf Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) |
topic_facet |
geo envir |
description |
The Eocene–Oligocene Transition (EOT) marks the onset of the Antarctic glaciation and the switch from greenhouse to icehouse climates. However, the driving mechanisms and the precise timing of the EOT remain controversial mostly due to the lack of well-dated stratigraphic records, especially in continental environments. Here we present a cyclo-magnetostratigraphic and sedimentological study of a ∼ 7.6 Myr long lacustrine record spanning the late Eocene to the earliest Oligocene, from a drill core in the Rennes Basin (France). Cyclostratigraphic analysis of natural gamma radiation (NGR) log data yields duration estimates of Chrons C12r through C16n.1n, providing additional constraints on the Eocene timescale. Correlations between the orbital eccentricity curve and the 405 kyr tuned NGR time series indicate that 33.71 and 34.10 Ma are the most likely proposed ages of the EO boundary. Additionally, the 405 kyr tuning calibrates the most pronounced NGR cyclicity to a period of ∼1 Myr, matching the g1–g5 eccentricity term, supporting its significant expression in continental depositional environments, and hypothesizing that the paleolake level may have behaved as a low-pass filter for orbital forcing. Two prominent changes in the sedimentary facies were detected across the EOT, which are temporally equivalent to the two main climatic steps, EOT-1 and Oi-1. We suggest that these two facies changes reflect the two major Antarctic cooling/glacial phases via the hydrological cycle, as significant shifts to drier and cooler climate conditions. Finally, the interval spanning the EOT precursor glacial event through EOT-1 is remarkably dominated by obliquity. This suggests preconditioning of the major Antarctic glaciation, either from obliquity directly affecting the formation/(in)stability of the incipient Antarctic Ice Sheet (AIS), or through obliquity modulation of the North Atlantic Deep Water production. |
format |
Article in Journal/Newspaper |
author |
S. Boulila G. Dupont-Nivet B. Galbrun H. Bauer J.-J. Châteauneuf |
author_facet |
S. Boulila G. Dupont-Nivet B. Galbrun H. Bauer J.-J. Châteauneuf |
author_sort |
S. Boulila |
title |
Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) |
title_short |
Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) |
title_full |
Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) |
title_fullStr |
Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) |
title_full_unstemmed |
Age and driving mechanisms of the Eocene–Oligocene transition from astronomical tuning of a lacustrine record (Rennes Basin, France) |
title_sort |
age and driving mechanisms of the eocene–oligocene transition from astronomical tuning of a lacustrine record (rennes basin, france) |
publisher |
Copernicus Publications |
publishDate |
2021 |
url |
https://doi.org/10.5194/cp-17-2343-2021 https://cp.copernicus.org/articles/17/2343/2021/cp-17-2343-2021.pdf https://doaj.org/article/14ac1be47d144f7096009dbf3312b097 |
geographic |
Antarctic The Antarctic |
geographic_facet |
Antarctic The Antarctic |
genre |
Antarc* Antarctic Ice Sheet North Atlantic Deep Water North Atlantic |
genre_facet |
Antarc* Antarctic Ice Sheet North Atlantic Deep Water North Atlantic |
op_source |
Climate of the Past, Vol 17, Pp 2343-2360 (2021) |
op_relation |
doi:10.5194/cp-17-2343-2021 1814-9324 1814-9332 https://cp.copernicus.org/articles/17/2343/2021/cp-17-2343-2021.pdf https://doaj.org/article/14ac1be47d144f7096009dbf3312b097 |
op_rights |
undefined |
op_doi |
https://doi.org/10.5194/cp-17-2343-2021 |
container_title |
Climate of the Past |
container_volume |
17 |
container_issue |
6 |
container_start_page |
2343 |
op_container_end_page |
2360 |
_version_ |
1766162880273580032 |