Lime muds and their genesis off-Northwestern India during the late Quaternary
DRS at CSIR-National Institute of Oceanography
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Title |
Lime muds and their genesis off-Northwestern India during the late Quaternary
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Creator |
Rao, V.P.
AnilKumar, A. Naqvi, S.W.A. Chivas, A.R. Sekar, B. Kessarkar, P.M. |
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Subject |
sediments
core analysis sea level changes climatic changes |
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Description |
Two sediment types were found in five gravity cores collected from water depths between 56 m and 121 m along the northwestern continental margin of India. lime mud was abundant in the lower section while siliciclastic sediments dominated the upper section. Lime mud-dominated sediments in shelf cores contained 60% - 75% carbonate, 0.3% - 0.6% Sr and terrigenous minerals, whereas those at the shelf break were found to have more than 90% carbonate, 0.6% - 0.8% Sr and traces of terrigenous minerals. Aragonite needles showing blunt edges, jointed needles and needles wrapped in smooth aragonite cement were found to be common. Stable (O and C) isotopes of lime mud indicate a potentially freshwater contribution for shelf cores and purely marine contribution for those at the shelf break. Calibrated radiocarbon ages of the lime mud ranged from 17.6 - 11.9 ka in different cores. The results reported here suggest that the lime muds in the shallow shelf are probably reworked from the Gulf of Kachchh, whereas those at the shelf break were biodetrital, initially formed on the carbonate platform during low stands of sea level and then exported. The change in lime mud-dominated to siliciclastic-dominated sediments in the cores may be due to climate change and rapid rise in sea level during the early Holocene.
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Date |
2012-07-27T09:02:14Z
2012-07-27T09:02:14Z 2012 |
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Type |
Journal Article
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Identifier |
Journal of Earth System Science, vol.121(3); 2012; 769-779
http://drs.nio.org/drs/handle/2264/4098 |
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Language |
en
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Rights |
© Indian Academy of Sciences. 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.
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Publisher |
Indian Academy of Sciences
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