Gravity anomalies, sediment loading and lithospheric flexure associated with the Krishna-Godavari basin, eastern continental margin of India

Gravity anomalies constrained by seismic data have been used to examine the long-term mechanical properties of the lithosphere beneath the Krishna-God avari basin, a deltaic sedimentary basin on the eastern continental margin of India. The gravity effect of the rift crust, sedimentary loading and ero sional unloading have been computed and the sum effect of these, when compa red with the observed gravity anomalies, gives a best fitting Te of 30 km a t the margin. The results suggest that the lithosphere, which was weak duri ng the early rifting-stage, has gained strength during sedimentation. The o nshore dipping doublet gravity anomaly at the margin reflects a weak rifted continental lithosphere abutting a strong oceanic lithosphere. Comparison with the results of similar investigations for the Bengal basin in the nort h and Cauvery basin in the south suggests increasing strength for the litho sphere from north to south. (C) 2000 Elsevier Science B.V. All rights reser ved.