Velocity Structure in Parts of the Gondwana Godavari Graben

Godavari graben, a palaeorift on the east coast of India, has been studied to delineate sedimentary thickness and basement configuration. First arrival seismic refraction data in the Chintalapudi sub-basin of Godavari graben have been utilized for 2-D ray trace modeling. Results indicate a thee layer velocity model, with velocities of 2.3-2.4, 3.2, and 4.0 kms^-1 for the Gondwana (Permian to Cretaceous) sediments. Maximum depth to the basement, of velocity 55-57 kms^-1, is to about 3 km in the deepest part of the sub-basin. The basement is possibly the Eastern Ghats suite of rocks. These results are in conformity with the thickness of stratigraphic sequences in a deep bore well in the basin, Another layer of velocity 5.8-6.3 kms^-1 is present at about 4 km depth through out the study region, representing the base of Eastern Ghats Suite of rocks.