The Indian Continental Lithosphere

Vinod K. Gaur

The paper presents a synthesized interpretation of the crust and upper mantle structure beneath most of the Indian continental lithosphere including that buried beneath the Deccan basalts, based on the published, and some unpublished, analyses of broadband seismic data. It also discusses the anisotropic structure of the Indian continental mantle, widely regarded as isotropic, by exploiting the consistency exhibited by a large number of null results with the small number of non-null results. The parallelism of the pervasive fast direction over much of the shield south of the foreland basin, with the relative asthenospheric flow, predicts the development of foliations in the horizontal plane which would inhibit splitting of the near vertically travelling shear waves such as the SKS. This severe limitation on SKS splitting results in the poverty of non-null results of splitting, which have been mistaken for the isotropic character of the Indian lithosphere.