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Continental shelf drift deposit indicates non-steady state Antarctic bottom water production in the Holocene


Harris, PT and Brancolini, G and Armand, LK and Busetti, M and Beaman, RJ and Giorgetti, G and Presti, M and Trincardi, F, Continental shelf drift deposit indicates non-steady state Antarctic bottom water production in the Holocene, Marine Geology, 179, (1-2) pp. 1-8. ISSN 0025-3227 (2001) [Refereed Article]

DOI: doi:10.1016/S0025-3227(01)00183-9


A late Quaternary, current-lain sediment drift deposit over 30 m in thickness has been discovered on the continental shelf of East Antarctica in an 850 m deep glacial trough off George Vth Land. Radiocarbon dating indicates that a period of rapid deposition on the drift (averaging 290 cm/kyr) occurred in the mid-Holocene, between about 3000 and 5000 yr before present (yr BP). Slower deposition rates of around 10 cm/kyr, during the past 0-3000 yr and from 5000 to about 13000 yr BP, coincides with the deposition of bioturbated, ice-rafted debris (IRD) rich, sandy mud under an energetic bottom current regime. In contrast, the mid-Holocene (3000-5000 yr BP) sediments are fine-grained, laminated to cross-laminated with minimal IRD content, and are contemporaneous with a period of warmer marine conditions with less sea ice production. This pattern suggests that bottom currents were weaker than present day in the mid-Holocene, and that the rate of dense bottom water production was reduced at that time. This scenario is consistent with the hypothesis of non-steady state rates of Antarctic bottom water production through the Holocene as recently proposed by Broecker and his colleagues. © 2001 Elsevier Science B.V. All rights reserved.

Item Details

Item Type:Refereed Article
Research Division:Earth Sciences
Research Group:Geology
Research Field:Sedimentology
Objective Division:Environmental Policy, Climate Change and Natural Hazards
Objective Group:Adaptation to climate change
Objective Field:Social impacts of climate change and variability
UTAS Author:Harris, PT (Dr Peter Harris)
UTAS Author:Armand, LK (Dr Leanne Armand)
UTAS Author:Beaman, RJ (Mr Robin Beaman)
ID Code:22206
Year Published:2001
Web of Science® Times Cited:46
Deposited By:CRC-Antarctic and Southern Ocean Environm
Deposited On:2001-08-01
Last Modified:2011-08-03

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