Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity
High-resolution records of carbon and oxygen isotopes and benthic foraminiferal accumulation rates for the Eocene-Oligocene section at Ocean Drilling Program Site 689(Maud Rise, Weddell Sea; paleodepth about 1500 m) were used to infer variations in paleoproductivity in relation to changes in climate...
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GSA, Geological Society of America
1996
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ftoceanrep:oai:oceanrep.geomar.de:31210 2023-05-15T13:39:45+02:00 Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity Diester-Haass, Liselotte Zahn-Knoll, Reiner 1996 text https://oceanrep.geomar.de/id/eprint/31210/ https://oceanrep.geomar.de/id/eprint/31210/1/Geology-1996-Diester-Haass-163-6.pdf https://doi.org/10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 en eng GSA, Geological Society of America https://oceanrep.geomar.de/id/eprint/31210/1/Geology-1996-Diester-Haass-163-6.pdf Diester-Haass, L. and Zahn-Knoll, R. (1996) Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity. Geology, 24 (2). pp. 163-166. DOI 10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 <https://doi.org/10.1130/0091-7613%281996%29024%3C0163%3AEOTITS%3E2.3.CO%3B2>. doi:10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 info:eu-repo/semantics/restrictedAccess Article PeerReviewed 1996 ftoceanrep https://doi.org/10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 2023-04-07T15:23:20Z High-resolution records of carbon and oxygen isotopes and benthic foraminiferal accumulation rates for the Eocene-Oligocene section at Ocean Drilling Program Site 689(Maud Rise, Weddell Sea; paleodepth about 1500 m) were used to infer variations in paleoproductivity in relation to changes in climate and ventilation of the deeper-water column. The benthic foraminiferal abundance and isotope records show short-term fluctuations at periodicities of 100 and 400 ka, implying orbitally driven climatic variations. Both records suggest that intermediate-depth water chemistry and primary productivity changed in response to climate. During the Eocene, productivity increased during cold periods and during cold-to-warm transitions, possibly as a result of increased upwelling of nutrient-rich waters. In the Oligocene, in contrast, productivity maxima occurred during intervals of low d18O values (presumably warmer periods), when a proto–polar front moved to the south of the location of Site 689. This profound transition in climate-productivity patterns occurred around 37 Ma, coeval with rapid changes toward increasing variability of the oxygen and carbon isotope and benthic abundance records and toward larger-amplitude d18O fluctuations. Therefore, we infer that, at this time, temperature fluctuations increased and a proto–polar front formed in conjunction with the first distinct pulsations in size of the Antarctic ice sheet. We speculate that this major change might have resulted from an initial opening of the Drake Passage at 37 Ma, at least for surface- and intermediate-water circulation. Article in Journal/Newspaper Antarc* Antarctic Drake Passage Ice Sheet Southern Ocean Weddell Sea OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) Antarctic Drake Passage Maud Rise ENVELOPE(3.000,3.000,-66.000,-66.000) Southern Ocean The Antarctic Weddell Weddell Sea |
institution |
Open Polar |
collection |
OceanRep (GEOMAR Helmholtz Centre für Ocean Research Kiel) |
op_collection_id |
ftoceanrep |
language |
English |
description |
High-resolution records of carbon and oxygen isotopes and benthic foraminiferal accumulation rates for the Eocene-Oligocene section at Ocean Drilling Program Site 689(Maud Rise, Weddell Sea; paleodepth about 1500 m) were used to infer variations in paleoproductivity in relation to changes in climate and ventilation of the deeper-water column. The benthic foraminiferal abundance and isotope records show short-term fluctuations at periodicities of 100 and 400 ka, implying orbitally driven climatic variations. Both records suggest that intermediate-depth water chemistry and primary productivity changed in response to climate. During the Eocene, productivity increased during cold periods and during cold-to-warm transitions, possibly as a result of increased upwelling of nutrient-rich waters. In the Oligocene, in contrast, productivity maxima occurred during intervals of low d18O values (presumably warmer periods), when a proto–polar front moved to the south of the location of Site 689. This profound transition in climate-productivity patterns occurred around 37 Ma, coeval with rapid changes toward increasing variability of the oxygen and carbon isotope and benthic abundance records and toward larger-amplitude d18O fluctuations. Therefore, we infer that, at this time, temperature fluctuations increased and a proto–polar front formed in conjunction with the first distinct pulsations in size of the Antarctic ice sheet. We speculate that this major change might have resulted from an initial opening of the Drake Passage at 37 Ma, at least for surface- and intermediate-water circulation. |
format |
Article in Journal/Newspaper |
author |
Diester-Haass, Liselotte Zahn-Knoll, Reiner |
spellingShingle |
Diester-Haass, Liselotte Zahn-Knoll, Reiner Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity |
author_facet |
Diester-Haass, Liselotte Zahn-Knoll, Reiner |
author_sort |
Diester-Haass, Liselotte |
title |
Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity |
title_short |
Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity |
title_full |
Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity |
title_fullStr |
Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity |
title_full_unstemmed |
Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity |
title_sort |
eocene-oligocene transition in the southern ocean: history of water mass circulation and biological productivity |
publisher |
GSA, Geological Society of America |
publishDate |
1996 |
url |
https://oceanrep.geomar.de/id/eprint/31210/ https://oceanrep.geomar.de/id/eprint/31210/1/Geology-1996-Diester-Haass-163-6.pdf https://doi.org/10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 |
long_lat |
ENVELOPE(3.000,3.000,-66.000,-66.000) |
geographic |
Antarctic Drake Passage Maud Rise Southern Ocean The Antarctic Weddell Weddell Sea |
geographic_facet |
Antarctic Drake Passage Maud Rise Southern Ocean The Antarctic Weddell Weddell Sea |
genre |
Antarc* Antarctic Drake Passage Ice Sheet Southern Ocean Weddell Sea |
genre_facet |
Antarc* Antarctic Drake Passage Ice Sheet Southern Ocean Weddell Sea |
op_relation |
https://oceanrep.geomar.de/id/eprint/31210/1/Geology-1996-Diester-Haass-163-6.pdf Diester-Haass, L. and Zahn-Knoll, R. (1996) Eocene-Oligocene transition in the Southern Ocean: History of water mass circulation and biological productivity. Geology, 24 (2). pp. 163-166. DOI 10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 <https://doi.org/10.1130/0091-7613%281996%29024%3C0163%3AEOTITS%3E2.3.CO%3B2>. doi:10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 |
op_rights |
info:eu-repo/semantics/restrictedAccess |
op_doi |
https://doi.org/10.1130/0091-7613(1996)024<0163:EOTITS>2.3.CO;2 |
_version_ |
1766122932510130176 |