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Seaward dipping reflectors along the SW continental margin of India: Evidence for volcanic passive margin

DRS at CSIR-National Institute of Oceanography

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Title Seaward dipping reflectors along the SW continental margin of India: Evidence for volcanic passive margin
 
Creator Ajay, K.K.
Chaubey, A.K.
Krishna, K.S.
Rao, D.G.
Sar, D.
 
Subject continental margins
seismic reflection
gravity model
Laccadive Ridge
 
Description Multi-channel seismic reflection profiles across the southwest continental margin of India (SWCMI) show presence of westerly dipping seismic reflectors beneath sedimentary strata along the western flank of the Laccadive Ridge-northernmost part of the Chagos-Laccadive Ridge system. Velocity structure, seismic character, 2D gravity model and geographic locations of the dipping reflectors suggest that these reflectors are volcanic in origin, which are interpreted as Seaward Dipping Reflectors (SDRs). The SDRs; 15 to 27 km wide overlain by approx. 1 km thick sediment; are observed at three locations and characterized by stack of laterally continuous, divergent and off-lapping reflectors. Occurrence of SDRs along western flank of the Laccadive Ridge adjacent to oceanic crust of the Arabian Basin and 2D crustal model deduced from free-air gravity anomaly suggest that they are genetically related to incipient volcanism during separation of Madagascar from India. It is suggested that (i) SWCMI is a volcanic passive margin developed during India-Madagascar breakup in the Late Cretaceous, and (ii) continent-ocean transition lies at western margin of the Laccadive Ridge, west of feather edge of the SDRs. Occurrence of SDRs on western flank of the Laccadive Ridge and inferred zone of transition from continent to ocean further suggest continental nature of crust of the Laccadive Ridge.
 
Date 2010-12-20T11:29:35Z
2010-12-20T11:29:35Z
2010
 
Type Journal Article
 
Identifier Journal of Earth System Science, vol.119(6); 2010; 803-813
http://drs.nio.org/drs/handle/2264/3756
 
Language en
 
Rights Copyright [2010]. 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 Indian Academy of Sciences