Encouraged by the delineation of the Mesozoic sediments in the northwestern quadrant of the Saurashtra peninsular region, ONGC Ltd. supported a major project for the delineation of sediments and mapping of the basement structure for oil exploration. Five magnetotelluric traverses across the Kutch region with 50 magnetotelluric sites have not only delineated yet another location, but also indicated sharp variation in the basement. It is observed from 1D and 2-D modeling of MT studies and also from gravity and Deep resistivity soundings, that the region west of Mundra village seems to possess large thickness of sediments. Interestingly, this region falls in the vicinity of the northwestern quadrant of Saurashtra region near Jamnagar (Ref: NGRI Report No: NGRI-2000-EXP-296).


Large part of this region is covered by volcanic rock and acts as a mask on the subsurface structures and makes it difficult for conventional geophysical techniques. Magnetotelluric studies using state-of-the art equipment covering most of the Saurashtra region with 690 stations showed the presence of thick (3-4 km) sediments below the volcanic rock towards north-western part of Saurashtra peninsula around Jamnagar . The presence of thick sediments towards the north western part of Saurashtra peninsula, which was FIRST indicated by MAGNETOTELLURICS and also decrease in resistivity of the sediments indicating the association of the marine environment of the sediments have opened up this region potential for oil exploration. This work was carried out as a sponsored project by ONGC Ltd. and is of classified in nature as the results are directly related to the oil potential of our country. (Ref: NGRI Report No: NGRI-98-EXP-237).


As in the case of Saurashtra, this region also covered by volcanic rocks and became a difficult terrain for conventional geophysical techniques. Magnetotelluric field studies using state-of-the art equipment near Nagpur-Wardha region with 138 stations along radial profiles and the strategic modeling have shown very thick sediments, of the order of 3 to 4 km. Apart from the estimations of the thickness of sediments, several structural features, basement undulations and also gave a new evidence for the possible extension of PRANHITA-GODAVARI Graben underneath the Deccan trap cover. This new evidence paved a way to the oil industry for exploration for coal and coal bed methane in Katol and it's surrounding regions. (Ref: NGRI Report No. NGRI-98-Expl.222)