Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean
Authigenic uranium is precipitated in reducing sediments and therefore responds both to changes in particulate organic carbon flux to the sediment and to changes in the oxygen concentration of bottom waters. By examining a large number of cores over a wide latitudinal and depth range in the Atlantic...
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Amer Geophysical Union
2001
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Online Access: | https://doi.org/10.1029/2000PA000542 http://ecite.utas.edu.au/101499 |
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ftunivtasecite:oai:ecite.utas.edu.au:101499 2023-05-15T18:21:10+02:00 Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean Chase, Z Anderson, RF Fleisher, MQ 2001 application/pdf https://doi.org/10.1029/2000PA000542 http://ecite.utas.edu.au/101499 en eng Amer Geophysical Union http://ecite.utas.edu.au/101499/1/468 Chase.pdf http://dx.doi.org/10.1029/2000PA000542 Chase, Z and Anderson, RF and Fleisher, MQ, Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean, Paleoceanography, 16, (5) pp. 468-478. ISSN 0883-8305 (2001) [Refereed Article] http://ecite.utas.edu.au/101499 Earth Sciences Physical Geography and Environmental Geoscience Palaeoclimatology Refereed Article PeerReviewed 2001 ftunivtasecite https://doi.org/10.1029/2000PA000542 2019-12-13T22:03:13Z Authigenic uranium is precipitated in reducing sediments and therefore responds both to changes in particulate organic carbon flux to the sediment and to changes in the oxygen concentration of bottom waters. By examining a large number of cores over a wide latitudinal and depth range in the Atlantic sector of the Southern Ocean, we hope to distinguish between a predominantly productivity-driven authigenic U signal and a circulation or sediment-focusing signal. We find little to no authigenic U in Holocene sediments throughout the South Atlantic Ocean. Glacial sediments north of ∼40S lack authigenic U, whereas sediments from the Subantarctic Zone show substantial enrichments in authigenic U relative to the Holocene (up to ∼5.3 ppm). The widespread distribution of glacial U enrichment, even in cores with no glacial-interglacial change in mass accumulation rate, implies that U deposition was not caused by an increased supply of organic carbon via sediment focusing. Authigenic U and organic carbon in a shallow core (∼1000 m) from the Subantarctic region show the same glacial increase found in the deep cores. Because this site was well ventilated during the Last Glacial Maximum, its record provides further evidence that increased glacial productivity of the Subantarctic region contributed to the high concentrations of authigenic U found in the glacial sections of deep cores. Article in Journal/Newspaper South Atlantic Ocean Southern Ocean eCite UTAS (University of Tasmania) Southern Ocean Paleoceanography 16 5 468 478 |
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Open Polar |
collection |
eCite UTAS (University of Tasmania) |
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ftunivtasecite |
language |
English |
topic |
Earth Sciences Physical Geography and Environmental Geoscience Palaeoclimatology |
spellingShingle |
Earth Sciences Physical Geography and Environmental Geoscience Palaeoclimatology Chase, Z Anderson, RF Fleisher, MQ Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean |
topic_facet |
Earth Sciences Physical Geography and Environmental Geoscience Palaeoclimatology |
description |
Authigenic uranium is precipitated in reducing sediments and therefore responds both to changes in particulate organic carbon flux to the sediment and to changes in the oxygen concentration of bottom waters. By examining a large number of cores over a wide latitudinal and depth range in the Atlantic sector of the Southern Ocean, we hope to distinguish between a predominantly productivity-driven authigenic U signal and a circulation or sediment-focusing signal. We find little to no authigenic U in Holocene sediments throughout the South Atlantic Ocean. Glacial sediments north of ∼40S lack authigenic U, whereas sediments from the Subantarctic Zone show substantial enrichments in authigenic U relative to the Holocene (up to ∼5.3 ppm). The widespread distribution of glacial U enrichment, even in cores with no glacial-interglacial change in mass accumulation rate, implies that U deposition was not caused by an increased supply of organic carbon via sediment focusing. Authigenic U and organic carbon in a shallow core (∼1000 m) from the Subantarctic region show the same glacial increase found in the deep cores. Because this site was well ventilated during the Last Glacial Maximum, its record provides further evidence that increased glacial productivity of the Subantarctic region contributed to the high concentrations of authigenic U found in the glacial sections of deep cores. |
format |
Article in Journal/Newspaper |
author |
Chase, Z Anderson, RF Fleisher, MQ |
author_facet |
Chase, Z Anderson, RF Fleisher, MQ |
author_sort |
Chase, Z |
title |
Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean |
title_short |
Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean |
title_full |
Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean |
title_fullStr |
Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean |
title_full_unstemmed |
Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean |
title_sort |
evidence from authigenic uranium for increased productivity of the glacial subantarctic ocean |
publisher |
Amer Geophysical Union |
publishDate |
2001 |
url |
https://doi.org/10.1029/2000PA000542 http://ecite.utas.edu.au/101499 |
geographic |
Southern Ocean |
geographic_facet |
Southern Ocean |
genre |
South Atlantic Ocean Southern Ocean |
genre_facet |
South Atlantic Ocean Southern Ocean |
op_relation |
http://ecite.utas.edu.au/101499/1/468 Chase.pdf http://dx.doi.org/10.1029/2000PA000542 Chase, Z and Anderson, RF and Fleisher, MQ, Evidence from authigenic uranium for increased productivity of the glacial Subantarctic Ocean, Paleoceanography, 16, (5) pp. 468-478. ISSN 0883-8305 (2001) [Refereed Article] http://ecite.utas.edu.au/101499 |
op_doi |
https://doi.org/10.1029/2000PA000542 |
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Paleoceanography |
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16 |
container_issue |
5 |
container_start_page |
468 |
op_container_end_page |
478 |
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1766200301078970368 |