Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes
Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope...
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ftunivsouthcar:oai:scholarcommons.sc.edu:geol_facpub-1039 2024-05-19T07:31:19+00:00 Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes Scher, Howie Martin, Ellen E 2008-01-19T08:00:00Z application/pdf https://scholarcommons.sc.edu/geol_facpub/40 https://scholarcommons.sc.edu/context/geol_facpub/article/1039/viewcontent/scher_paleoceanography.pdf unknown Scholar Commons https://scholarcommons.sc.edu/geol_facpub/40 https://scholarcommons.sc.edu/context/geol_facpub/article/1039/viewcontent/scher_paleoceanography.pdf Scher, H. D. & Martin, E. E. (2008). Oligocene deep water export from the North Atlantic and thedevelopment of the Antarctic Circumpolar Current examined withneodymium isotopes. Paleoceanography, 23 (PA1025), 1-12. © Paleoceanography 2008, American Geophysical Union Faculty Publications Earth Sciences text 2008 ftunivsouthcar 2024-04-30T23:59:54Z Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope compositionsdominates the record. This trend is interrupted by shifts toward more radiogenic compositions near the early/lateOligocene boundary and the Oligocene/Miocene boundary. Overall, eNd values at Agulhas Ridge are moreradiogenic than at other Atlantic locations, and are similar to those at Indian Ocean locations. The pattern ofvariability is remarkably similar to Nd isotope results from Walvis Ridge (South Atlantic) and Ninetyeast Ridge(Indian Ocean). In contrast, Agulhas Ridge and Maud Rise Nd isotope records do not show similar patterns overthis interval. Results from this study indicate that deep water in the Atlantic flowed predominantly from north tosouth during the Oligocene and Miocene, and that export of Northern Component Water (NCW) to the SouthernOcean increased in the late Oligocene. There is also evidence for efficient exchange of deep waters between theAtlantic sector of the Southern Ocean and the Indian Ocean, although the direction of deep water flow is notentirely clear from these data. The shifts to more radiogenic Nd isotopic compositions most likely representincreases in the flux of Pacific waters through Drake Passage, and the timing of these events reflect developmentof a mature Antarctic Circumpolar Current (ACC). The relative timing of increased NCW export and ACCmaturation support hypotheses that link deep water formation in the North Atlantic to the opening of DrakePassage. Text Antarc* Antarctic Drake Passage North Atlantic Southern Ocean University of South Carolina Libraries: Scholar Commons |
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Earth Sciences Scher, Howie Martin, Ellen E Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes |
topic_facet |
Earth Sciences |
description |
Neodymium (Nd) isotopes were measured on 181 samples of fossil fish teeth recovered from Oligocene toMiocene sections at Ocean Drilling Program Site 1090 (3700 m water depth) on Agulhas Ridge in the Atlanticsector of the Southern Ocean. A long-term decreasing trend toward less radiogenic Nd isotope compositionsdominates the record. This trend is interrupted by shifts toward more radiogenic compositions near the early/lateOligocene boundary and the Oligocene/Miocene boundary. Overall, eNd values at Agulhas Ridge are moreradiogenic than at other Atlantic locations, and are similar to those at Indian Ocean locations. The pattern ofvariability is remarkably similar to Nd isotope results from Walvis Ridge (South Atlantic) and Ninetyeast Ridge(Indian Ocean). In contrast, Agulhas Ridge and Maud Rise Nd isotope records do not show similar patterns overthis interval. Results from this study indicate that deep water in the Atlantic flowed predominantly from north tosouth during the Oligocene and Miocene, and that export of Northern Component Water (NCW) to the SouthernOcean increased in the late Oligocene. There is also evidence for efficient exchange of deep waters between theAtlantic sector of the Southern Ocean and the Indian Ocean, although the direction of deep water flow is notentirely clear from these data. The shifts to more radiogenic Nd isotopic compositions most likely representincreases in the flux of Pacific waters through Drake Passage, and the timing of these events reflect developmentof a mature Antarctic Circumpolar Current (ACC). The relative timing of increased NCW export and ACCmaturation support hypotheses that link deep water formation in the North Atlantic to the opening of DrakePassage. |
format |
Text |
author |
Scher, Howie Martin, Ellen E |
author_facet |
Scher, Howie Martin, Ellen E |
author_sort |
Scher, Howie |
title |
Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes |
title_short |
Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes |
title_full |
Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes |
title_fullStr |
Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes |
title_full_unstemmed |
Oligocene Deep Water Export from the North Atlantic and the Development of the Antarctic Circumpolar Current Examined with Neodymium Isotopes |
title_sort |
oligocene deep water export from the north atlantic and the development of the antarctic circumpolar current examined with neodymium isotopes |
publisher |
Scholar Commons |
publishDate |
2008 |
url |
https://scholarcommons.sc.edu/geol_facpub/40 https://scholarcommons.sc.edu/context/geol_facpub/article/1039/viewcontent/scher_paleoceanography.pdf |
genre |
Antarc* Antarctic Drake Passage North Atlantic Southern Ocean |
genre_facet |
Antarc* Antarctic Drake Passage North Atlantic Southern Ocean |
op_source |
Faculty Publications |
op_relation |
https://scholarcommons.sc.edu/geol_facpub/40 https://scholarcommons.sc.edu/context/geol_facpub/article/1039/viewcontent/scher_paleoceanography.pdf |
op_rights |
Scher, H. D. & Martin, E. E. (2008). Oligocene deep water export from the North Atlantic and thedevelopment of the Antarctic Circumpolar Current examined withneodymium isotopes. Paleoceanography, 23 (PA1025), 1-12. © Paleoceanography 2008, American Geophysical Union |
_version_ |
1799469168430415872 |