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Late Pleistocene sedimentation: A case study of the central Indian Ocean Basin

DRS at CSIR-National Institute of Oceanography

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Title Late Pleistocene sedimentation: A case study of the central Indian Ocean Basin
 
Creator Borole, D.V.
 
Subject sedimentation
pleistocene
thorium
biogenic deposits
winnowing
 
Description Concentration-depth profiles of excess sup(230)Th have been measured in five sediment cores from the central Indian Ocean Basin to determine their accumulation rates and excess sup(230)Th flux to the depositional environment. Sedimentation accumulation rates ranged between 1 and 5 mm ky sup(-1). The excess sup(230)Th inventories in the cores range from 44 to 481 dpm cm sup(-2), considerably lower than that expected from its production in the overlying water column. These low excess sup(230)Th inventories (relative to its production) have been attributed to the effects of winnowing by bottom currents. The absence of sup(230)Th sub(ex) in core (Sagar Kanya-176) has been attributed to the lack of sediment deposition in this area causEd. by the influence of Antarctic Bottom Water (AABW). This study shows that the deposition of biogenic silica and lithogenic components exhibited orders of magnitude variations during Late Pleistocene. The biogenic flux variation are attributed to productivity changes while the episodic variations in the non-biogenic flux could result from major changes in the influx of terrigenous materials via the Ganges-Brahmaputra
 
Date 2009-05-06T10:44:16Z
2009-05-06T10:44:16Z
1993
 
Type Journal Article
 
Identifier Deep-Sea Research (A: Oceanographic Research Papers), Vol.40; 761-775p.
http://drs.nio.org/drs/handle/2264/2832
 
Language en
 
Rights Copyright [1993]. All efforts have been made to respect the copyright to the best of our knowledge. Inadvertent omissions, if brought to our notice, stand for correction and withdrawal of document from this repository.
 
Publisher Pergamon