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Authors
Affiliations
1 National Geophysical Research Institute, Uppal Road, Hyderabad - 500 007, IN
2 National Geophysical Research Institute, Uppal Road, Hyderabad - 500 007
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 68, No Spl Iss 3 (2006), Pagination: 425-432
Abstract
Neodymium isotopic composition (εNd) of authigenic marine sediments is an important tracer of the continental input of Nd to the oceans As the residence time of neodymium in seawater 1s short when compared to the mixing time of the oceans, its isotopic composition shows regional variations In this paper, we present the surface seawater Nd isotopic record from a deep-sea sediment core (SK-72) from the Bay of Bengal Our results support the inference of Vance and Burton (1999) that thoroughly cleaned foraminifera can be used to infer glacial-to-Interglaciacl hanges ln the Nd isotopicc omposition of surface seawater The striking feature of this record is a sharp shift in εNd (˜ 4 epsilon units) from the Last Glacial Maximum (LGM) to Holocene In addition, the variations documented in εNd, show a remarkable correspondence with those of the oxygen isotopic composition of planktonic foraminifera,indicating a process that controls the Nd isotopic compoition, which responds in phase with climate We infer that the shift in εNd from the LGM to Holocene is due to a change in the weathering pattern in the Himalaya-Tibet and the Indo-Burman Ranges glacial erosion during the LGM and a strong monsoonal effect durtng the Holocene.
Keywords
Neodymium Isotopes, LGM, Holocene, Weathering, Monsoon, Riverine Input, Oxygen Isotopes, Planktonic and Benthic Foraminifera.
