Basement structure of Godavari basin, India - Geophysical modelling

摘要

In the present study an attempt has been made to obtain a comprehensive picture of the basement structure through the gravity and magnetic profiles across the Godavari basin, in southern India. The available gravity and magnetic profiles are modelled, jointly, by assuming geologically feasible basement structure and sedimentary columns. The basement picture of the Godavari basin comprising the Proterozoic sediments and the Gondwana sediments, appears to be an asymmetric basin, but the Gondwana basin seems to be a symmetric graben. The contact between the Gondwana sediments and the northeastern Proterozoic sediments is a steep fault, which is the master fault. The thickness of the sediments in the middle of the Godavari basin is around 7 kin, which might include some thickness of Proterozoic sediments also. Some low-density granites may also constitute this thick column. Modelling suggests that the basement rocks abutting the Proterozoic sediments on either side of the basin, are of higher density and susceptibility than the granitoids. These data do not manifest any basic bodies in the sediments. It is likely that the main graben formation is after the deposition of Proterozoic sediments on either side of the Gondwana sediments.