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Morphotectonic architecture of an India–Madagascar breakup related anomalous submarine terrace complex on the southwest continental margin of India

DRS at CSIR-National Institute of Oceanography

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Title Morphotectonic architecture of an India–Madagascar breakup related anomalous submarine terrace complex on the southwest continental margin of India
 
Creator Yatheesh, V.
Kurian, P.J.
Bhattacharya, G.C.
Rajan, S.
 
Subject terraces
escarpments
shear zone
continental margins
crustal structure
seismic reflection profiles
 
Description An anomalous lateral bathymetric protrusion [Alleppey–Trivandrum Terrace Complex (ATTC)] in the form of two contiguous terrace-like features exists in the mid-continental slope off southwest coast of India. This bathymetric protrusion and a bathymetric notch in the Northern Madagascar Ridge (NMR) have been postulated as conjugate features related to India–Madagascar separation in Late Cretaceous. However, geoscientific studies aimed to understand the crustal structure and genesis of the ATTC or its postulated conjugate region are meagre and ambiguous. In this context, the present study, based on recently acquired as well existing bathymetry, gravity, magnetic and multi-channel seismic reflection data, was carried out to understand the morphotectonic architecture of the ATTC. The bathymetric data suggest an escarpment [Chain-Kairali Escarpment (CKE)] to demarcate the westward limit of the ATTC and another escarpment [Quilon Escarpment (QE)] to demarcate the boundary between the southerly, larger ‘Trivandrum Terrace (TT)’ and northerly, smaller Alleppey Terrace (AT). The multichannel seismic reflection data suggests a block-faulted basement and presence of a nearly N–S trending wide basement high in the central part of the Trivandrum Terrace. Forward modelling of gravity data constrained by seismic reflection information suggests that the crustal structure of the ATTC region is comparable to thinned continental crust. Forward modelling of prominent high amplitude magnetic anomalies suggest that the thinned continental crust of the ATTC region also contains volcanic bodies as intrusives/extrusives. The CKE is inferred to be a sheared continental margin segment along which the SE coast of Madagascar glided past India and the volcanic emplacements in the ATTC region perhaps relates to the Marion Hotspot volcanism
 
Date 2013-09-06T07:41:00Z
2013-09-06T07:41:00Z
2013
 
Type Journal Article
 
Identifier Marine and Petroleum Geology, vol.46; 2013; 304-318
no
http://drs.nio.org/drs/handle/2264/4357
 
Language en
 
Relation Mar_Pet_Geol_46_304.jpg
 
Rights An edited version of this paper was published by Elsevier. Copyright [2013] Elsevier
 
Publisher Elsevier