K.S. Prakasam

High-velocity anomaly under the Deccan Volcanic Province

Abstract Tomographic modelling of P-wave residuals at 22 vertical-component seismograph stations operated in the Deccan Volcanic Province (DVP) in west-central India and the Dharwar Craton point to the existence of a large, deep (at least 300 km), high-velocity anomaly (1–3% faster) directly beneath most of the DVP and Dharwar Craton. There is also marginal evidence that the westernmost part of the DVP may be characterised by low velocity (up to −1.5%) to a depth of about 200 km. This coherent high-velocity anomaly under the DVP and its extension into the south Indian shield is viewed as a lithospheric root, an architecture characteristic of Precambrian shields.