Submarine terrace limestones from the continental slope off Saurashtra-Bombay: Evidence of Late Quaternary neotectonic activity
DRS at CSIR-National Institute of Oceanography
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Title |
Submarine terrace limestones from the continental slope off Saurashtra-Bombay: Evidence of Late Quaternary neotectonic activity
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Creator |
Rao, V.P.
Veerayya, M. |
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Subject |
limestone
terraces submarine features geomorphology tectonics palaeo studies seismic data quaternary |
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Description |
Bathymetric and shallow seismic data from the continental slope off Saurashtra-Bombay indicate wide submarine terraces at 130, 145 and 170 m and reefal structures at 320-360 m water depths. 10 cm thick slabs of limestones are recovered from the 130 m depth terrace. Some of these limestones consist of thin micrite layer on the top and a sandy layer below and others are similar to calcarenites. They contain greater than 95% aragonite and minor high and low-magnesium calcite. Acicular aragonite cements occur as isopachous crusts. Dissolution and clotting of aragonite needles and drusy calcite in the interstices indicate cementation of the limestones at inter-tidal conditions. The age of the limestones is 11,900 years BP. These imply that the 130 m depth terrace was at intertidal depths at about 12,000 years BP. The eustatic sea-level, however, was at - 90 m at 12,000 years BP. This disparity suggests neotectonic activity and subsidence by about 40 m on the Saurashtra-Bombay region some time after 12,000 years BP.
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Date |
2009-01-21T10:43:23Z
2009-01-21T10:43:23Z 1996 |
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Type |
Journal Article
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Identifier |
Current Science, Vol.71; 36-41p.
http://drs.nio.org/drs/handle/2264/2209 |
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Language |
en
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Rights |
Copyright [1996]. 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 |
Current Science Association, Bangalore, India
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