Abstract

A large unexplored sub-basin around Nagpur-Wardha with considerable thickness of Gondwana sediments was identified in the northeastern part of Deccan Syneclise situated in the central part of India. The basin is covered with a thick trap poured out during Late Cretaceous-Palaeocene time but is readily identified by a gravity low at Katol, west of Nagpur. To ascertain the sedimentary thickness, 2-D forward gravity modeling along two profiles passing through Katol low are attempted. Gravity modeling produces non-unique interpretations, thus Magneto-telluric (MT) information was used to ascertain the Deccan trap thickness. The prospective area was identified initially on the basis of gravity low and subsequently mapped using an integrated package of geological model and geophysical techniques. A thick sequence of Lower Gondwana sediments of the order of 5000m below trap is predicted within the Katol low. Sediments of Barakar Formation of the order of 1500m estimated to be deposited in it. The incremental thickness of source and reservoir rocks enhances the HC prospectivity of the basin. The gravity lows of less sedimentary thickness mapped in the region may become important coal bed methane (CBM) exploration target, since the coal seams occurring within 1000m depth with adequate overburden of basaltic cover are likely to be of suitable rank.