Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity
[1] During the Eocene-Oligocene transition, Earth cooled significantly from a greenhouse to an icehouse climate. Nannofossil assemblages from Southern Ocean sites enable evaluation of paleoceanographic changes and, hence, of the oceanic response to Antarctic ice sheet evolution during the Eocene and...
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Online Access: | http://hdl.handle.net/11380/994920 https://doi.org/10.1002/2013PA002518 |
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ftunivmodena:oai:iris.unimore.it:11380/994920 2024-04-14T08:04:23+00:00 Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity Giuliana Villa FIORONI, Chiara Davide Persico Andrew P. Roberts Fabio Florindo Giuliana, Villa Fioroni, Chiara Davide, Persico Andrew P., Robert Fabio, Florindo 2014 STAMPA http://hdl.handle.net/11380/994920 https://doi.org/10.1002/2013PA002518 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000334349800007 volume:29 (3) firstpage:223 lastpage:237 numberofpages:15 journal:PALEOCEANOGRAPHY http://hdl.handle.net/11380/994920 doi:10.1002/2013PA002518 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84896423929 info:eu-repo/semantics/closedAccess Nannofossil Eocene Oligocene Antarctica info:eu-repo/semantics/article 2014 ftunivmodena https://doi.org/10.1002/2013PA002518 2024-03-21T17:40:13Z [1] During the Eocene-Oligocene transition, Earth cooled significantly from a greenhouse to an icehouse climate. Nannofossil assemblages from Southern Ocean sites enable evaluation of paleoceanographic changes and, hence, of the oceanic response to Antarctic ice sheet evolution during the Eocene and Oligocene. A combination of environmental factors such as sea surface temperature and nutrient availability are recorded by the assemblages of calcifying organisms, and can be interpreted as responses to the following changes. A cooling trend, which started in the Middle Eocene, was interrupted by transient warming during the Middle Eocene Climatic optimum and by several short cooling episodes. The cooling episode at 39.6 Ma preceded a shift toward an interval that was dominated by oligotrophic nannofossil assemblages from ~39.1 to ~36.2 Ma. We suggest that these oligotrophic conditions were associated with increased water mass stratification, low nutrient contents, and high efficiency of the oceanic biological pump that, in turn, promoted sequestration of carbon from surface waters, which favored cooling. After 36.2 Ma, we document a large synchronous surface water productivity turnover with a dominant eutrophic nannofossil assemblage that was accompanied by a pronounced increase in magnetotactic bacterial abundance. This turnover likely reflects a response of coccolithophorids to changed nutrient inputs that was likely related to partial deglaciation of a transient Antarctic ice sheet and/or to iron delivery to the sea surface. Eutrophic conditions were maintained throughout the Oligocene, which was characterized by a nannofossil assemblage shift toward cool conditions at the Eocene–Oligocene transition. Finally, a warm nannofossil assemblage in the Late Oligocene indicates a warming phase. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Southern Ocean Archivio della ricerca dell'Università di Modena e Reggio Emilia (Unimore: IRIS) Antarctic Southern Ocean Paleoceanography 29 3 223 237 |
institution |
Open Polar |
collection |
Archivio della ricerca dell'Università di Modena e Reggio Emilia (Unimore: IRIS) |
op_collection_id |
ftunivmodena |
language |
English |
topic |
Nannofossil Eocene Oligocene Antarctica |
spellingShingle |
Nannofossil Eocene Oligocene Antarctica Giuliana Villa FIORONI, Chiara Davide Persico Andrew P. Roberts Fabio Florindo Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity |
topic_facet |
Nannofossil Eocene Oligocene Antarctica |
description |
[1] During the Eocene-Oligocene transition, Earth cooled significantly from a greenhouse to an icehouse climate. Nannofossil assemblages from Southern Ocean sites enable evaluation of paleoceanographic changes and, hence, of the oceanic response to Antarctic ice sheet evolution during the Eocene and Oligocene. A combination of environmental factors such as sea surface temperature and nutrient availability are recorded by the assemblages of calcifying organisms, and can be interpreted as responses to the following changes. A cooling trend, which started in the Middle Eocene, was interrupted by transient warming during the Middle Eocene Climatic optimum and by several short cooling episodes. The cooling episode at 39.6 Ma preceded a shift toward an interval that was dominated by oligotrophic nannofossil assemblages from ~39.1 to ~36.2 Ma. We suggest that these oligotrophic conditions were associated with increased water mass stratification, low nutrient contents, and high efficiency of the oceanic biological pump that, in turn, promoted sequestration of carbon from surface waters, which favored cooling. After 36.2 Ma, we document a large synchronous surface water productivity turnover with a dominant eutrophic nannofossil assemblage that was accompanied by a pronounced increase in magnetotactic bacterial abundance. This turnover likely reflects a response of coccolithophorids to changed nutrient inputs that was likely related to partial deglaciation of a transient Antarctic ice sheet and/or to iron delivery to the sea surface. Eutrophic conditions were maintained throughout the Oligocene, which was characterized by a nannofossil assemblage shift toward cool conditions at the Eocene–Oligocene transition. Finally, a warm nannofossil assemblage in the Late Oligocene indicates a warming phase. |
author2 |
Giuliana, Villa Fioroni, Chiara Davide, Persico Andrew P., Robert Fabio, Florindo |
format |
Article in Journal/Newspaper |
author |
Giuliana Villa FIORONI, Chiara Davide Persico Andrew P. Roberts Fabio Florindo |
author_facet |
Giuliana Villa FIORONI, Chiara Davide Persico Andrew P. Roberts Fabio Florindo |
author_sort |
Giuliana Villa |
title |
Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity |
title_short |
Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity |
title_full |
Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity |
title_fullStr |
Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity |
title_full_unstemmed |
Middle Eocene to Late Oligocene Antarctic Glaciation/Deglaciation and Southern Ocean productivity |
title_sort |
middle eocene to late oligocene antarctic glaciation/deglaciation and southern ocean productivity |
publishDate |
2014 |
url |
http://hdl.handle.net/11380/994920 https://doi.org/10.1002/2013PA002518 |
geographic |
Antarctic Southern Ocean |
geographic_facet |
Antarctic Southern Ocean |
genre |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet Southern Ocean |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000334349800007 volume:29 (3) firstpage:223 lastpage:237 numberofpages:15 journal:PALEOCEANOGRAPHY http://hdl.handle.net/11380/994920 doi:10.1002/2013PA002518 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84896423929 |
op_rights |
info:eu-repo/semantics/closedAccess |
op_doi |
https://doi.org/10.1002/2013PA002518 |
container_title |
Paleoceanography |
container_volume |
29 |
container_issue |
3 |
container_start_page |
223 |
op_container_end_page |
237 |
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1796300873916219392 |