Vertical density contrast and mapping of basement, Conrad and Moho morphologies through 2D spectral analysis of gravity data in and around Odisha, India

Abstract

Power spectrum analysis of Complete Bouguer Anomaly (CBA) map of Eastern Ghat Mobile Belt (EGMB) and its surroundings in India through Two Dimensional (2D) spectral analysis has provided estimates of the ensemble average depths for the density discontinuities which represent crustal inhomogeneities. The spectral analysis method has helped to estimate the depths of a perturbing body sources which are obtained from the negative slopes of the linear relationship between the logarithmic power spectrum and the wave-numbers of the gravity field. The detailed analysis reveals three horizontal discontinuities (i) Phanerozoic sediment thickness (ii) Basement depth and (iii) Conrad discontinuity. The average thickness of Phanerozoic sediments is estimated to be 3km whereas depth of basement and Conrad discontinuity are at 7km and 14.5km respectively. Additionally Mohorovicic discontinuity also estimated at a depth of 32.8km in the study region.