Concealed anatomy and new geological features beneath desert areas of NW India – Constrained from high resolution aero-geophysical data

Abstract

The vast swathe of area in the Trans-Aravalli region between the western part of the South Delhi Fold Belt and eastern part of the Barmer basin, north-western India exhibits limited geological information due to thick sand cover of the Thar Desert. The present study is to unravel the hidden architecture of the above area using recently acquired high-resolution aero-magnetic data. Here, our interpreted results brought out a buried ring structure in the northern part and NW-SE trending constellation of linear magnetic highs in the southern part. Considering the regional geological milieu, our study correlates the buried ring structure with a possible remnant volcanic cone of the Neoproterozoic silicic Malani Large Igneous Province. Secondly, the significant NW-SE trending linear magnetic highs in the south possibly represents a humongous dyke swarm activity, facilitated by the intricate network of fractures. The orientation of these magnetic linear are conspicuously similar with the Deccan linked Sarnu-Dandali dykes and regional Barmer-Cambay rift system. The northwestern portion of study area displays high magnetic and gravity responses of long wavelength features indicating crustal heterogeneity. The study for the first time documents two concealed structures, which may hold a link of Neoproterozoic Malani and Mesozoic Deccan magmatic pulses.

Keywords

• Delhi Fold Belt
• Barmer basin
• Geophysics
• Buried ring
• Dyke swarm