Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin
Two sediment cores from the Murray Canyons area, south of Kangaroo Island, South Australia, were investigated for proxy-records to reconstruct past productivity of the surface waters in the area over the last 175 ka. The proxies used included concentrations of aragonite, low- and high-Mg calcite, to...
Published in: | Palaeogeography, Palaeoclimatology, Palaeoecology |
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Online Access: | http://hdl.handle.net/1885/73655 https://doi.org/10.1016/j.palaeo.2005.01.012 https://openresearch-repository.anu.edu.au/bitstream/1885/73655/5/MigratedxPub3776_2005.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/73655/7/01_Gingele_Late_Quaternary_fluctuations_2005.pdf.jpg |
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ftanucanberra:oai:openresearch-repository.anu.edu.au:1885/73655 2024-01-14T10:10:53+01:00 Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin Gingele, Franz De Deckker, Patrick http://hdl.handle.net/1885/73655 https://doi.org/10.1016/j.palaeo.2005.01.012 https://openresearch-repository.anu.edu.au/bitstream/1885/73655/5/MigratedxPub3776_2005.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/73655/7/01_Gingele_Late_Quaternary_fluctuations_2005.pdf.jpg unknown Elsevier 0031-0182 http://hdl.handle.net/1885/73655 doi:10.1016/j.palaeo.2005.01.012 https://openresearch-repository.anu.edu.au/bitstream/1885/73655/5/MigratedxPub3776_2005.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/73655/7/01_Gingele_Late_Quaternary_fluctuations_2005.pdf.jpg Palaeogeography, Palaeoclimatology, Palaeoecology Keywords: nutrient cycling organic carbon productivity Quaternary Australasia Australia Eastern Hemisphere Kangaroo Island oceanic regions South Australia Southern Ocean World Foraminifera Globigerina bulloides Macropus sp. d13C Murray canyons Palaeoproductivity Precessional cycles Primary production Journal article ftanucanberra https://doi.org/10.1016/j.palaeo.2005.01.012 2023-12-15T09:39:13Z Two sediment cores from the Murray Canyons area, south of Kangaroo Island, South Australia, were investigated for proxy-records to reconstruct past productivity of the surface waters in the area over the last 175 ka. The proxies used included concentrations of aragonite, low- and high-Mg calcite, total carbonate, total organic carbon, sulfur and δ13C of Globigerina bulloides. Cyclic increases in palaeoproductivity were observed to be in tune with insolation minima at 30°S. The atmospheric conditions during insolation minima were comparable to present winter patterns, when strong westerly winds dominate over the area and bring dust from the central desert areas. During the last insolation minimum (last glacial maximum: LGM), the Murray Canyons laid directly under the "Eastern Australian Dust Plume". Dust could have fertilized surface waters and initiated the observed productivity "increases" on a precessional time scale. The core from the more westerly canyons is richer in organic matter; this could be attributed to the influx of organic matter from shallower water, which is carried by an overflow of hypersaline water from the Spencer Gulf to the deep ocean, using the western canyons as conduits. There is no evidence that the "Palaeo-Murray River", which debouches close to the core sites during sealevel lowstands, was a major source of nutrients for surface waters. Although total carbonate concentrations remained high, planktonic foraminifers were fewer in numbers during these periods, possibly due to reduced light penetration caused by suspended river material. A deglacial minimum in δ13C of Globigerina bulloides, observed in other cores from the southern hemisphere and attributed to a major hydrographic change south of the Polar Front, is also visible in our two cores, thus attesting to the global significance of the event. Article in Journal/Newspaper Southern Ocean Australian National University: ANU Digital Collections Southern Ocean Kangaroo Island ENVELOPE(-97.260,-97.260,59.910,59.910) Palaeogeography, Palaeoclimatology, Palaeoecology 220 3-4 361 373 |
institution |
Open Polar |
collection |
Australian National University: ANU Digital Collections |
op_collection_id |
ftanucanberra |
language |
unknown |
topic |
Keywords: nutrient cycling organic carbon productivity Quaternary Australasia Australia Eastern Hemisphere Kangaroo Island oceanic regions South Australia Southern Ocean World Foraminifera Globigerina bulloides Macropus sp. d13C Murray canyons Palaeoproductivity Precessional cycles Primary production |
spellingShingle |
Keywords: nutrient cycling organic carbon productivity Quaternary Australasia Australia Eastern Hemisphere Kangaroo Island oceanic regions South Australia Southern Ocean World Foraminifera Globigerina bulloides Macropus sp. d13C Murray canyons Palaeoproductivity Precessional cycles Primary production Gingele, Franz De Deckker, Patrick Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin |
topic_facet |
Keywords: nutrient cycling organic carbon productivity Quaternary Australasia Australia Eastern Hemisphere Kangaroo Island oceanic regions South Australia Southern Ocean World Foraminifera Globigerina bulloides Macropus sp. d13C Murray canyons Palaeoproductivity Precessional cycles Primary production |
description |
Two sediment cores from the Murray Canyons area, south of Kangaroo Island, South Australia, were investigated for proxy-records to reconstruct past productivity of the surface waters in the area over the last 175 ka. The proxies used included concentrations of aragonite, low- and high-Mg calcite, total carbonate, total organic carbon, sulfur and δ13C of Globigerina bulloides. Cyclic increases in palaeoproductivity were observed to be in tune with insolation minima at 30°S. The atmospheric conditions during insolation minima were comparable to present winter patterns, when strong westerly winds dominate over the area and bring dust from the central desert areas. During the last insolation minimum (last glacial maximum: LGM), the Murray Canyons laid directly under the "Eastern Australian Dust Plume". Dust could have fertilized surface waters and initiated the observed productivity "increases" on a precessional time scale. The core from the more westerly canyons is richer in organic matter; this could be attributed to the influx of organic matter from shallower water, which is carried by an overflow of hypersaline water from the Spencer Gulf to the deep ocean, using the western canyons as conduits. There is no evidence that the "Palaeo-Murray River", which debouches close to the core sites during sealevel lowstands, was a major source of nutrients for surface waters. Although total carbonate concentrations remained high, planktonic foraminifers were fewer in numbers during these periods, possibly due to reduced light penetration caused by suspended river material. A deglacial minimum in δ13C of Globigerina bulloides, observed in other cores from the southern hemisphere and attributed to a major hydrographic change south of the Polar Front, is also visible in our two cores, thus attesting to the global significance of the event. |
format |
Article in Journal/Newspaper |
author |
Gingele, Franz De Deckker, Patrick |
author_facet |
Gingele, Franz De Deckker, Patrick |
author_sort |
Gingele, Franz |
title |
Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin |
title_short |
Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin |
title_full |
Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin |
title_fullStr |
Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin |
title_full_unstemmed |
Late Quaternary fluctuations of palaeoproductivity in the Murray Canyons area, South Australian continental margin |
title_sort |
late quaternary fluctuations of palaeoproductivity in the murray canyons area, south australian continental margin |
publisher |
Elsevier |
url |
http://hdl.handle.net/1885/73655 https://doi.org/10.1016/j.palaeo.2005.01.012 https://openresearch-repository.anu.edu.au/bitstream/1885/73655/5/MigratedxPub3776_2005.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/73655/7/01_Gingele_Late_Quaternary_fluctuations_2005.pdf.jpg |
long_lat |
ENVELOPE(-97.260,-97.260,59.910,59.910) |
geographic |
Southern Ocean Kangaroo Island |
geographic_facet |
Southern Ocean Kangaroo Island |
genre |
Southern Ocean |
genre_facet |
Southern Ocean |
op_source |
Palaeogeography, Palaeoclimatology, Palaeoecology |
op_relation |
0031-0182 http://hdl.handle.net/1885/73655 doi:10.1016/j.palaeo.2005.01.012 https://openresearch-repository.anu.edu.au/bitstream/1885/73655/5/MigratedxPub3776_2005.pdf.jpg https://openresearch-repository.anu.edu.au/bitstream/1885/73655/7/01_Gingele_Late_Quaternary_fluctuations_2005.pdf.jpg |
op_doi |
https://doi.org/10.1016/j.palaeo.2005.01.012 |
container_title |
Palaeogeography, Palaeoclimatology, Palaeoecology |
container_volume |
220 |
container_issue |
3-4 |
container_start_page |
361 |
op_container_end_page |
373 |
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1788065740525404160 |