Three dimensional lithospheric structure of the western continental margin of India constrained from gravity modelling: implication for tectonic evolution

Abstract

This paper describes a 3-D lithospheric density model of the Western Continental Margin of India (WCMI) based on forwardmodelling of gravity data derived from satellite altimetry over the ocean and surface measurements on the Indian peninsula. The model covers the northeastern Arabian Sea and the western part of the Indian Peninsula and incorporates constraints from a wide variety of geophysical and geological information. Salient features of the density model include: (1) the Moho depth varying from 13 km below the oceanic crust to 46 km below the continental interior; (2) the lithosphere-asthenosphere boundary (LAB) located at depths between 70 km in the southwestern corner (under oceanic crust) and about 165 km below the continental region; (3) thickening of the crust under the Chagos-Laccadive and Laxmi Ridges and (4) a revised definition of the continent-ocean boundary.