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Structure and isostatic compensation of the Comorin Ridge, north central Indian Ocean

DRS at CSIR-National Institute of Oceanography

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Title Structure and isostatic compensation of the Comorin Ridge, north central Indian Ocean
 
Creator Sreejith, K.M.
Krishna, K.S.
Bansal, A.R.
 
Subject gravity anomalies
continental margins
plate tectonics
volcanism
 
Description Bathymetry, gravity and magnetic data (about 9200 l km) of the Comorin Ridge, north central Indian Ocean were investigated using the transfer function and forward model techniques to understand the mode of isostatic compensation and origin of the ridge. The ridge extends for about 500 km in NNW-SSE direction and associates with low-amplitude gravity anomalies ranging from 25 to 30 mGal compared to the ridge relief, suggesting that the anomalies are compensated at deeper depths. From Admittance analysis an Airy model or local compensation with an elastic plate thickness (T sub(e)) of about 3 km and crust thickness (t) of 15-20 km are suggested for the southern part of the Comorin Ridge (south of 5 degrees N), whereas for the northern part a flexural plate model with an elastic thickness of about 15 km is obtained. Admittance analysis together with the results from gravity forward modelling reveal that the south part was emplaced on relatively weak oceanic crust with both surface and subsurface loading, while the north part was emplaced on the continental crust. Based on present studies and published plate kinematic models we interpret that the Comorin Ridge was evolved at about 90 Ma during the rift stage of Madagascar from the southwest of India. We have also demarcated the continent-ocean boundary (COB) west of Sri Lanka and southern tip of India, which runs across the strike of the ridge, placing the northern part of the ridge on continent and southern part on oceanic crust. On the southern part of the ridge eastern flank is steep-faulted up to 0.6 km and is controlled by the 79 degrees E FZ and then by COB.
 
Date 2008-11-21T07:29:13Z
2008-11-21T07:29:13Z
2008
 
Type Journal Article
 
Identifier Geophysical Journal International, vol.175; 729-741p.
http://drs.nio.org/drs/handle/2264/1487
 
Language en
 
Rights Copyright [2008]. 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 Royal Astronomical Society