Regional geoelectric structure beneath Deccan Volcanic Province of the Indian subcontinent using magnetotellurics

摘要: Understanding deep continental structure and the seismotectonics of Deccan trap covered region has attained greater importance in recent years. For imaging crustal structure, magnetotelluric (MT) investigations have been carried out along three long profiles viz. Guhagarh–Sangole (GS), Sangole–Partur (SP), Edlabad–Khandwa (EK) one short profile Nanasi–Mokhad (NM). The results GS, SP NM show that traps lie directly over high resistive basement with thin inter-trappean sediments, where large thickness order 1.5–2.0 km, delineated EK across Narmada– Son–Lineament zone. is intersected by faults/fractures, which are clearly as narrow steep conducting features at a few locations. also seen from aeromagnetic anomalies. Towards southern part profile, these spatially correlated Kurduwadi rift proposed earlier gravity studies. Apart extending to levels, present study indicates additional conductive basement. variation resistivity GS can be attributed block Koyna region. Similar profile. thickness, based on various geophysical methods, varies gradually 1.8 km towards west 0.3 east. While this general trend, sharp observed near Koyna. more (150–200 Ω m) compared east (50–60 indicating compact or denser nature for basalt west. upper crust highly (5000–10,000 m), lower moderately (500– 1000 m). In study, discussed regional geoelectrical lateral presence anomalous conductors crust. © 2007 Elsevier B.V. All rights reserved.