Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period
Reconstructing past detrital flux and provenance in the Southern Ocean provides information about changes in source regions associated with climate variations and transport pathways. We present a Last Glacial Maximum (LGM) to Holocene comparison of 230Th normalised fluxes combined with sediment prov...
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ftcolumbiauniv:oai:academiccommons.columbia.edu:10.7916/D8RV0ZJ7 2023-05-15T13:50:01+02:00 Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period Noble, Taryn L. Piotrowski, Alexander M. Robinson, Laura F. McManus, Jerry F. Hillenbrand, Claus-Dieter Bory, Aloys Jean-Mathias 2012 https://doi.org/10.7916/D8RV0ZJ7 English eng https://doi.org/10.7916/D8RV0ZJ7 Paleoclimatology Submarine geology Articles 2012 ftcolumbiauniv https://doi.org/10.7916/D8RV0ZJ7 2019-04-04T08:08:50Z Reconstructing past detrital flux and provenance in the Southern Ocean provides information about changes in source regions associated with climate variations and transport pathways. We present a Last Glacial Maximum (LGM) to Holocene comparison of 230Th normalised fluxes combined with sediment provenance data (Pb, Nd and Sr isotopes) from a latitudinal core transect in the eastern Atlantic sector of the Southern Ocean (ODP Leg 177 cores). We compare the radiogenic isotopic composition (IC) of detritus in these cores to that of cores proximal to potential source areas. We observe a well-defined latitudinal Holocene gradient in both detrital flux and provenance of sediment. High detrital fluxes in the north are associated with terrigenous material derived from southern Africa, while low detrital fluxes in the south are associated with supply from southern South America, West Antarctica and the South Sandwich Islands. The data suggest that this well-defined Holocene gradient in detrital flux and sediment provenance is controlled by the flow of the Antarctic Circumpolar Current (ACC) and the position of its frontal zones. The LGM is characterised by 2 to 6 times higher than modern detrital fluxes at most ODP Leg 177 sites. The LGM detrital fluxes do not show a latitudinal trend and suggest a greater supply of glaciogenic detritus sourced from southern South America. Glacial Patagonian outwash sediments (< 5 μm fraction) were analysed and compared to the bulk compositions of the marine sediments. The Pb IC of the Patagonian sediments is very similar to the glacial IC of sediments in the Scotia Sea and at ~ 49° S latitude in the eastern Atlantic sector. We propose that the glacial IC of sediments is controlled by increased delivery of Patagonian detritus initially supplied by glaciers and then transported at depth via the ACC. Article in Journal/Newspaper Antarc* Antarctic Antarctica Scotia Sea South Sandwich Islands Southern Ocean West Antarctica Columbia University: Academic Commons Antarctic Southern Ocean The Antarctic West Antarctica Scotia Sea Sandwich Islands South Sandwich Islands |
institution |
Open Polar |
collection |
Columbia University: Academic Commons |
op_collection_id |
ftcolumbiauniv |
language |
English |
topic |
Paleoclimatology Submarine geology |
spellingShingle |
Paleoclimatology Submarine geology Noble, Taryn L. Piotrowski, Alexander M. Robinson, Laura F. McManus, Jerry F. Hillenbrand, Claus-Dieter Bory, Aloys Jean-Mathias Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period |
topic_facet |
Paleoclimatology Submarine geology |
description |
Reconstructing past detrital flux and provenance in the Southern Ocean provides information about changes in source regions associated with climate variations and transport pathways. We present a Last Glacial Maximum (LGM) to Holocene comparison of 230Th normalised fluxes combined with sediment provenance data (Pb, Nd and Sr isotopes) from a latitudinal core transect in the eastern Atlantic sector of the Southern Ocean (ODP Leg 177 cores). We compare the radiogenic isotopic composition (IC) of detritus in these cores to that of cores proximal to potential source areas. We observe a well-defined latitudinal Holocene gradient in both detrital flux and provenance of sediment. High detrital fluxes in the north are associated with terrigenous material derived from southern Africa, while low detrital fluxes in the south are associated with supply from southern South America, West Antarctica and the South Sandwich Islands. The data suggest that this well-defined Holocene gradient in detrital flux and sediment provenance is controlled by the flow of the Antarctic Circumpolar Current (ACC) and the position of its frontal zones. The LGM is characterised by 2 to 6 times higher than modern detrital fluxes at most ODP Leg 177 sites. The LGM detrital fluxes do not show a latitudinal trend and suggest a greater supply of glaciogenic detritus sourced from southern South America. Glacial Patagonian outwash sediments (< 5 μm fraction) were analysed and compared to the bulk compositions of the marine sediments. The Pb IC of the Patagonian sediments is very similar to the glacial IC of sediments in the Scotia Sea and at ~ 49° S latitude in the eastern Atlantic sector. We propose that the glacial IC of sediments is controlled by increased delivery of Patagonian detritus initially supplied by glaciers and then transported at depth via the ACC. |
format |
Article in Journal/Newspaper |
author |
Noble, Taryn L. Piotrowski, Alexander M. Robinson, Laura F. McManus, Jerry F. Hillenbrand, Claus-Dieter Bory, Aloys Jean-Mathias |
author_facet |
Noble, Taryn L. Piotrowski, Alexander M. Robinson, Laura F. McManus, Jerry F. Hillenbrand, Claus-Dieter Bory, Aloys Jean-Mathias |
author_sort |
Noble, Taryn L. |
title |
Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period |
title_short |
Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period |
title_full |
Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period |
title_fullStr |
Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period |
title_full_unstemmed |
Greater supply of Patagonian-sourced detritus and transport by the ACC to the Atlantic sector of the Southern Ocean during the last glacial period |
title_sort |
greater supply of patagonian-sourced detritus and transport by the acc to the atlantic sector of the southern ocean during the last glacial period |
publishDate |
2012 |
url |
https://doi.org/10.7916/D8RV0ZJ7 |
geographic |
Antarctic Southern Ocean The Antarctic West Antarctica Scotia Sea Sandwich Islands South Sandwich Islands |
geographic_facet |
Antarctic Southern Ocean The Antarctic West Antarctica Scotia Sea Sandwich Islands South Sandwich Islands |
genre |
Antarc* Antarctic Antarctica Scotia Sea South Sandwich Islands Southern Ocean West Antarctica |
genre_facet |
Antarc* Antarctic Antarctica Scotia Sea South Sandwich Islands Southern Ocean West Antarctica |
op_relation |
https://doi.org/10.7916/D8RV0ZJ7 |
op_doi |
https://doi.org/10.7916/D8RV0ZJ7 |
_version_ |
1766252752853270528 |