hide
Free keywords:
-
Abstract:
The Indian shield is a mosaic of Archean cratons and Proterozoic mobile belts along with many intra-cratonic rift basins and major volcanic provinces. These Precambrian terrains preserve the imprints of earlier supercontinental cycles and major tectono-thermal events through which the Indian shield crust had evolved. In this study, we analyze different scales gravity anomalies for a better understanding of the subsurface in terms of structure below cratons and mobile belts through mapped fault/shear zones, magmatic events revealing the extent of underplating and crustal thickness variations. Large amount of crustal seismic data are used to carry out the 3-D nonlinear seismically constrained gravity inversion to delineate the Moho structure as well as density heterogeneities across the different domains. The inversion gave rise to Moho depth variations between 30-65 km with the best-fit mean difference of ~ -0.37 km and standard deviation of ~ 4 km with the seismic data. The derived structure reveals a distinct characteristics below the cratons and mobile belts with a generalized shallow Moho below the rift basins and volcanic provinces. Further, these results along with the seismological LAB depth estimates are used to obtain many insights on the nature of the craton-mobile belt interactions to understand the lithosphere evolution since the Proterozoic times.
