44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1
Stable carbon and oxygen isotope analyses were conducted on well-preserved planktonic and benthic foraminifers from a continuous middle Eocene to Oligocene sequence at Ocean Drilling Program (ODP) Site 748 on the Kerguelen Plateau. Benthic foraminifer δ 1 8θ values show a 1.0 ‰ increase through the...
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ftciteseerx:oai:CiteSeerX.psu:10.1.1.542.3829 2023-05-15T14:02:32+02:00 44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 James C. Zachos William A. Berggren Marie-pierre Aubry Andreas Mackensen The Pennsylvania State University CiteSeerX Archives application/pdf http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.542.3829 http://www.es.ucsc.edu/~jzachos/pubs/Zachos_etal_ODP120.pdf en eng http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.542.3829 http://www.es.ucsc.edu/~jzachos/pubs/Zachos_etal_ODP120.pdf Metadata may be used without restrictions as long as the oai identifier remains attached to it. http://www.es.ucsc.edu/~jzachos/pubs/Zachos_etal_ODP120.pdf text ftciteseerx 2016-01-08T11:07:39Z Stable carbon and oxygen isotope analyses were conducted on well-preserved planktonic and benthic foraminifers from a continuous middle Eocene to Oligocene sequence at Ocean Drilling Program (ODP) Site 748 on the Kerguelen Plateau. Benthic foraminifer δ 1 8θ values show a 1.0 ‰ increase through the middle and upper Eocene, followed by a rapid 1.2%c increase in the lowermost Oligocene (35.5 Ma). Surface-dwelling planktonic foraminifer δ 1 8 θ values increase in the lowermost Oligocene, but only by 0.6%e whereas intermediate-depth planktonic foraminifers show an increase of about l.O‰. Benthic foraminifer δ13C values increase by 0.9 ‰ in the lowermost Oligocene at precisely the same time as the large δ 1 8θ increase, whereas planktonic foraminifer δ13C values show little or no change. Site 748 oxygen isotope and paleontological records suggest that southern Indian Ocean surface and intermediate waters underwent significant cooling from the early to late Eocene. The rapid 1.2%o oxygen isotope increase recorded by benthic foraminifers just above the Eocene/Oligocene boundary represents the ubiquitous early Oligocene δ 1 8 θ event. The shift here is unique, however, as it coincided with the sudden appearance of ice-rafted debris (IRD), providing the first direct link between Antarctic glacial activity and the earliest Oligocene δ 1 8 θ increase. The δ 1 8θ increase caused by the ice-volume change in the early Oligocene is constrained by (1) related changes in the planktonic to benthic foraminifer δ 1 8θ gradient at Site 748 and (2) comparisons of late Eocene and early Oligocene planktonic foraminifer δ 1 8θ values from various latitudes. Both of these records indicate that 0.3%c to 0.4%0 of the early Oligocene δ 1 8 θ increase was ice-volume related. Text Antarc* Antarctic Unknown Antarctic Kerguelen Indian |
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Open Polar |
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Unknown |
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ftciteseerx |
language |
English |
description |
Stable carbon and oxygen isotope analyses were conducted on well-preserved planktonic and benthic foraminifers from a continuous middle Eocene to Oligocene sequence at Ocean Drilling Program (ODP) Site 748 on the Kerguelen Plateau. Benthic foraminifer δ 1 8θ values show a 1.0 ‰ increase through the middle and upper Eocene, followed by a rapid 1.2%c increase in the lowermost Oligocene (35.5 Ma). Surface-dwelling planktonic foraminifer δ 1 8 θ values increase in the lowermost Oligocene, but only by 0.6%e whereas intermediate-depth planktonic foraminifers show an increase of about l.O‰. Benthic foraminifer δ13C values increase by 0.9 ‰ in the lowermost Oligocene at precisely the same time as the large δ 1 8θ increase, whereas planktonic foraminifer δ13C values show little or no change. Site 748 oxygen isotope and paleontological records suggest that southern Indian Ocean surface and intermediate waters underwent significant cooling from the early to late Eocene. The rapid 1.2%o oxygen isotope increase recorded by benthic foraminifers just above the Eocene/Oligocene boundary represents the ubiquitous early Oligocene δ 1 8 θ event. The shift here is unique, however, as it coincided with the sudden appearance of ice-rafted debris (IRD), providing the first direct link between Antarctic glacial activity and the earliest Oligocene δ 1 8 θ increase. The δ 1 8θ increase caused by the ice-volume change in the early Oligocene is constrained by (1) related changes in the planktonic to benthic foraminifer δ 1 8θ gradient at Site 748 and (2) comparisons of late Eocene and early Oligocene planktonic foraminifer δ 1 8θ values from various latitudes. Both of these records indicate that 0.3%c to 0.4%0 of the early Oligocene δ 1 8 θ increase was ice-volume related. |
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The Pennsylvania State University CiteSeerX Archives |
format |
Text |
author |
James C. Zachos William A. Berggren Marie-pierre Aubry Andreas Mackensen |
spellingShingle |
James C. Zachos William A. Berggren Marie-pierre Aubry Andreas Mackensen 44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 |
author_facet |
James C. Zachos William A. Berggren Marie-pierre Aubry Andreas Mackensen |
author_sort |
James C. Zachos |
title |
44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 |
title_short |
44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 |
title_full |
44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 |
title_fullStr |
44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 |
title_full_unstemmed |
44. ISOTOPE AND TRACE ELEMENT GEOCHEMISTRY OF EOCENE AND OLIGOCENE FORAMINIFERS FROM SITE 748, KERGUELEN PLATEAU1 |
title_sort |
44. isotope and trace element geochemistry of eocene and oligocene foraminifers from site 748, kerguelen plateau1 |
url |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.542.3829 http://www.es.ucsc.edu/~jzachos/pubs/Zachos_etal_ODP120.pdf |
geographic |
Antarctic Kerguelen Indian |
geographic_facet |
Antarctic Kerguelen Indian |
genre |
Antarc* Antarctic |
genre_facet |
Antarc* Antarctic |
op_source |
http://www.es.ucsc.edu/~jzachos/pubs/Zachos_etal_ODP120.pdf |
op_relation |
http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.542.3829 http://www.es.ucsc.edu/~jzachos/pubs/Zachos_etal_ODP120.pdf |
op_rights |
Metadata may be used without restrictions as long as the oai identifier remains attached to it. |
_version_ |
1766272851861569536 |