The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses
Abstract Biostratigraphic study and re-examination of 22 late Eocene to early Oligocene sections provides data in support of three and possibly a fourth late Eocene impact events in the G. index Zone during a period of about 1 Ma of the middle Priabonian between 34.7 and 35.7 Ma. No major species ex...
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Cambridge University Press (CUP)
1993
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Online Access: | http://dx.doi.org/10.1017/s0016756800020550 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800020550 |
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crcambridgeupr:10.1017/s0016756800020550 2024-05-12T07:55:21+00:00 The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses Molina, Eustoquio Gonzalvo, Concepción Keller, Gerta 1993 http://dx.doi.org/10.1017/s0016756800020550 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800020550 en eng Cambridge University Press (CUP) https://www.cambridge.org/core/terms Geological Magazine volume 130, issue 4, page 483-499 ISSN 0016-7568 1469-5081 Geology journal-article 1993 crcambridgeupr https://doi.org/10.1017/s0016756800020550 2024-04-18T06:54:01Z Abstract Biostratigraphic study and re-examination of 22 late Eocene to early Oligocene sections provides data in support of three and possibly a fourth late Eocene impact events in the G. index Zone during a period of about 1 Ma of the middle Priabonian between 34.7 and 35.7 Ma. No major species extinctions or significant species abundance changes directly coincide with these impact events. Species extinctions are gradual and selective, affecting primarily cool-temperature-intolerant surface dwellers. These extinctions began with the onset of global cooling during the early middle Eocene and culminated near the Eocene/Oligocene boundary. The global cooling was associated with the isolation of Antarctica as Australia moved northward, the development of a circum-Antarctic circulation, growth of Antarctic ice sheet beginning by late middle Eocene time and a change from a thermospheric to thermohaline circulation. We find no evidence that the multiple late Eocene impact events directly contributed to the climatic deterioration already in progress. Article in Journal/Newspaper Antarc* Antarctic Antarctica Ice Sheet Cambridge University Press Antarctic Geological Magazine 130 4 483 499 |
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Open Polar |
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Cambridge University Press |
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crcambridgeupr |
language |
English |
topic |
Geology |
spellingShingle |
Geology Molina, Eustoquio Gonzalvo, Concepción Keller, Gerta The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
topic_facet |
Geology |
description |
Abstract Biostratigraphic study and re-examination of 22 late Eocene to early Oligocene sections provides data in support of three and possibly a fourth late Eocene impact events in the G. index Zone during a period of about 1 Ma of the middle Priabonian between 34.7 and 35.7 Ma. No major species extinctions or significant species abundance changes directly coincide with these impact events. Species extinctions are gradual and selective, affecting primarily cool-temperature-intolerant surface dwellers. These extinctions began with the onset of global cooling during the early middle Eocene and culminated near the Eocene/Oligocene boundary. The global cooling was associated with the isolation of Antarctica as Australia moved northward, the development of a circum-Antarctic circulation, growth of Antarctic ice sheet beginning by late middle Eocene time and a change from a thermospheric to thermohaline circulation. We find no evidence that the multiple late Eocene impact events directly contributed to the climatic deterioration already in progress. |
format |
Article in Journal/Newspaper |
author |
Molina, Eustoquio Gonzalvo, Concepción Keller, Gerta |
author_facet |
Molina, Eustoquio Gonzalvo, Concepción Keller, Gerta |
author_sort |
Molina, Eustoquio |
title |
The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
title_short |
The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
title_full |
The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
title_fullStr |
The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
title_full_unstemmed |
The Eocene-Oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
title_sort |
eocene-oligocene planktic foraminiferal transition: extinctions, impacts and hiatuses |
publisher |
Cambridge University Press (CUP) |
publishDate |
1993 |
url |
http://dx.doi.org/10.1017/s0016756800020550 https://www.cambridge.org/core/services/aop-cambridge-core/content/view/S0016756800020550 |
geographic |
Antarctic |
geographic_facet |
Antarctic |
genre |
Antarc* Antarctic Antarctica Ice Sheet |
genre_facet |
Antarc* Antarctic Antarctica Ice Sheet |
op_source |
Geological Magazine volume 130, issue 4, page 483-499 ISSN 0016-7568 1469-5081 |
op_rights |
https://www.cambridge.org/core/terms |
op_doi |
https://doi.org/10.1017/s0016756800020550 |
container_title |
Geological Magazine |
container_volume |
130 |
container_issue |
4 |
container_start_page |
483 |
op_container_end_page |
499 |
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1798835126127296512 |