Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse
The Eocene‐Oligocene transition (EOT) marked the initiation of large‐scale Antarctic glaciation. This fundamental change in Cenozoic climate state is recorded in deep‐sea sediments by a rapid benthic foraminiferal δ18O increase and appearance of ice‐rafted debris in the Southern Ocean. However, we k...
Published in: | Paleoceanography and Paleoclimatology |
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Online Access: | https://eprints.soton.ac.uk/437914/ https://eprints.soton.ac.uk/437914/1/Haiblen_et_al_2019_Paleoceanography_and_Paleoclimatology_2_.pdf |
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ftsouthampton:oai:eprints.soton.ac.uk:437914 2023-07-30T03:56:38+02:00 Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse Haiblen, A. M. Opdyke, B. N. Roberts, A. P. Heslop, D. Wilson, P. A. 2019-12-12 text https://eprints.soton.ac.uk/437914/ https://eprints.soton.ac.uk/437914/1/Haiblen_et_al_2019_Paleoceanography_and_Paleoclimatology_2_.pdf en English eng https://eprints.soton.ac.uk/437914/1/Haiblen_et_al_2019_Paleoceanography_and_Paleoclimatology_2_.pdf Haiblen, A. M., Opdyke, B. N., Roberts, A. P., Heslop, D. and Wilson, P. A. (2019) Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse. Paleoceanography and Paleoclimatology, 34 (12), 1995-2004. (doi:10.1029/2019PA003679 <http://dx.doi.org/10.1029/2019PA003679>). other Article PeerReviewed 2019 ftsouthampton https://doi.org/10.1029/2019PA003679 2023-07-09T22:34:33Z The Eocene‐Oligocene transition (EOT) marked the initiation of large‐scale Antarctic glaciation. This fundamental change in Cenozoic climate state is recorded in deep‐sea sediments by a rapid benthic foraminiferal δ18O increase and appearance of ice‐rafted debris in the Southern Ocean. However, we know little about the magnitude of cooling associated with the EOT in shallow water environments, particularly at middle to high latitudes. Here we present new stratigraphic records of the C13r/C13n magnetochron boundary and the EOT in the clay‐rich Blanche Point Formation, South Australia. The Blanche Point Formation was deposited in a shallow shelf setting (water depths of <100 m) at a paleolatitude of ~51°S. We present high‐resolution δ18O, δ13C, and Mg/Ca records of environmental change from well‐preserved benthic foraminifera of latest Eocene age at this site. A marked, negative δ13C excursion occurs immediately before EOT Step 1 and may be a globally representative signal. An ~2 °C cooling of shallow shelf seawater is evident from benthic foraminiferal Mg/Ca across Step 1. This cooling signal is both sufficient to account fully for the δ18O increase in our data and is of similar amplitude to that documented in published records for shallow shelf and upper water column open ocean settings, which suggests no obvious polar amplification of this cooling signal. Our results strengthen the evidence base for attributing EOT Step 1 to global cooling with little contribution from ice volume growth and contradict the mechanism suggested to explain the inferred northward migration of the intertropical convergence zone in the contemporaneous equatorial Pacific Ocean. Article in Journal/Newspaper Antarc* Antarctic Southern Ocean University of Southampton: e-Prints Soton Antarctic Blanche ENVELOPE(140.018,140.018,-66.663,-66.663) Blanche Point ENVELOPE(-55.731,-55.731,49.933,49.933) Pacific Southern Ocean Paleoceanography and Paleoclimatology 34 12 1995 2004 |
institution |
Open Polar |
collection |
University of Southampton: e-Prints Soton |
op_collection_id |
ftsouthampton |
language |
English |
description |
The Eocene‐Oligocene transition (EOT) marked the initiation of large‐scale Antarctic glaciation. This fundamental change in Cenozoic climate state is recorded in deep‐sea sediments by a rapid benthic foraminiferal δ18O increase and appearance of ice‐rafted debris in the Southern Ocean. However, we know little about the magnitude of cooling associated with the EOT in shallow water environments, particularly at middle to high latitudes. Here we present new stratigraphic records of the C13r/C13n magnetochron boundary and the EOT in the clay‐rich Blanche Point Formation, South Australia. The Blanche Point Formation was deposited in a shallow shelf setting (water depths of <100 m) at a paleolatitude of ~51°S. We present high‐resolution δ18O, δ13C, and Mg/Ca records of environmental change from well‐preserved benthic foraminifera of latest Eocene age at this site. A marked, negative δ13C excursion occurs immediately before EOT Step 1 and may be a globally representative signal. An ~2 °C cooling of shallow shelf seawater is evident from benthic foraminiferal Mg/Ca across Step 1. This cooling signal is both sufficient to account fully for the δ18O increase in our data and is of similar amplitude to that documented in published records for shallow shelf and upper water column open ocean settings, which suggests no obvious polar amplification of this cooling signal. Our results strengthen the evidence base for attributing EOT Step 1 to global cooling with little contribution from ice volume growth and contradict the mechanism suggested to explain the inferred northward migration of the intertropical convergence zone in the contemporaneous equatorial Pacific Ocean. |
format |
Article in Journal/Newspaper |
author |
Haiblen, A. M. Opdyke, B. N. Roberts, A. P. Heslop, D. Wilson, P. A. |
spellingShingle |
Haiblen, A. M. Opdyke, B. N. Roberts, A. P. Heslop, D. Wilson, P. A. Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse |
author_facet |
Haiblen, A. M. Opdyke, B. N. Roberts, A. P. Heslop, D. Wilson, P. A. |
author_sort |
Haiblen, A. M. |
title |
Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse |
title_short |
Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse |
title_full |
Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse |
title_fullStr |
Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse |
title_full_unstemmed |
Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse |
title_sort |
midlatitude southern hemisphere temperature change at the end of the eocene greenhouse shortly before dawn of the oligocene icehouse |
publishDate |
2019 |
url |
https://eprints.soton.ac.uk/437914/ https://eprints.soton.ac.uk/437914/1/Haiblen_et_al_2019_Paleoceanography_and_Paleoclimatology_2_.pdf |
long_lat |
ENVELOPE(140.018,140.018,-66.663,-66.663) ENVELOPE(-55.731,-55.731,49.933,49.933) |
geographic |
Antarctic Blanche Blanche Point Pacific Southern Ocean |
geographic_facet |
Antarctic Blanche Blanche Point Pacific Southern Ocean |
genre |
Antarc* Antarctic Southern Ocean |
genre_facet |
Antarc* Antarctic Southern Ocean |
op_relation |
https://eprints.soton.ac.uk/437914/1/Haiblen_et_al_2019_Paleoceanography_and_Paleoclimatology_2_.pdf Haiblen, A. M., Opdyke, B. N., Roberts, A. P., Heslop, D. and Wilson, P. A. (2019) Midlatitude Southern Hemisphere temperature change at the end of the Eocene greenhouse shortly before dawn of the Oligocene Icehouse. Paleoceanography and Paleoclimatology, 34 (12), 1995-2004. (doi:10.1029/2019PA003679 <http://dx.doi.org/10.1029/2019PA003679>). |
op_rights |
other |
op_doi |
https://doi.org/10.1029/2019PA003679 |
container_title |
Paleoceanography and Paleoclimatology |
container_volume |
34 |
container_issue |
12 |
container_start_page |
1995 |
op_container_end_page |
2004 |
_version_ |
1772813987955605504 |