Crustal Density Structure of Kumaon Himalaya, India based on Gravity Modeling

Abstract:

We acquire a new high-resolution gravity dataset along a ~200 km long transect from the Indo-Gangetic plains in the south to the Main Central thrust (MCT) zone in the north. We analyze the Bouguer gravity anomaly and topography across the Kumaon Himalaya by spectral methods and modeling to constrain the crustal density structure. The power spectrum of Bouguer anomaly is analyzed to derive the mean depth of the interfaces. The spectral analysis suggests three-layered structure in the lithosphere with two prominent segments at 41 km and 14 km corresponding to the Moho and the Himalayan décollement thrust, respectively. We model a detailed crustal density structure using existing constraints. The model will be discussed in light of past geological and geophysical studies to explain the tectonic settings of the region.