Delineation of intra crustal horizon in Eastern Dharwar Craton – An aeromagnetic evidence

A correlative study of two mutually independent geophysical properties like magnetic susceptibility variations and shear wave velocity structure of the crust has been carried out in a part of the Eastern Dharwar Craton of Indian peninsular shield. Analysis of the aeromagnetic anomaly field over an area of 35,000 km2 comprising the peninsular gneissic basement complex and a part of Cuddapah Basin has resulted in identification of two distinct magnetic horizons: one at a depth of 2 km and the other at a depth of 12 km. Correlation of these results with the inferences made by the inversion of Rayleigh wave phase velocity and other geophysical studies has confirmed the presence of a crustal layer at a depth of 12 km. This horizon has been inferred to be the depth to the lower boundary of the upper crust in this region.

Research highlights
► A prominent crustal layer at a depth of 12 km in the EDC has been delineated by aeromagnetics.
► This crustal layer is associated with perceptible variations in magnetic susceptibility and had discernible shear wave velocity structure.
► The crustal layer is inferred to be the bottom of the upper crust in the part of EDC.