Density inhomogeneities beneath Deccan Volcanic Province, India as derivedfrom gravity data

New gravity measurements at close spacing (1-2 km) along three profiles (si milar to 550 km each), starting from west coast of India upto the eastern m argin of the Deccan Volcanic Province (DVP), are carried out to understand the subsurface density structures and tectonics of the region. The computed density model, constrained with seismic and other geophysical information, delineates high-density (3.1 g/cm(3)) underplated lower crust and low dens ity (3.2 g/cm(3)) upper mantle along the west coast of India, which may be attributed to the interaction of the Reunion hot spot with the Indian litho sphere and rifting along the west coast of India. Analysis and modelling of the gravity data also suggest different sources for two large wave length gravity 'lows', namely the "Koyna low" and the "Kurduwadi low", observed ov er the DVP. The "Koyna low" is caused mainly by isostatic compensation, man ifested as crustal thickening upto 40 km with low density (3.2 g/cm(3)) upp er mantle, while the source of the "Kurduwadi low" appears to be shallow an d is mainly attributed to the emplacement of low-density material, such as granitic bodies along fractures/shear zones. (C) 2000 Elsevier Science Ltd. All rights reserved.