Abstract

Cauvery Basin is the southernmost among the Mesozoic rift basins of India lying along its east coast. The basin came into existence due to separation of Indian plate from Antarctica during the fragmentation of Gondwanaland. In rift basins, hydrocarbons generated from pre rift/ syn rift sources have a tendency to accumulate on the gentle slope both in syn rift and in immediate post rift sediments. Present study established that in Cauvery basin most of the established hydrocarbon accumulations occur on the gentle flanks of the syn rift half grabens. Similar phenomenon of preferential hydrocarbon accumulation has been observed in prominent petroliferous basins, viz., Reconcavo (Tequipe and Aqua Grande Field, Brazil) and Gulf of Suez (Middle East). In the present study, the preferential proclivity of hydrocarbons on gentle flanks has been examined from Generation-Migration-Entrapment point of view. The reactivated NNE-SSW set of faults and the transfer faults have been the conduits for vertical migration. The stratal up dips towards the gentle flank is the guiding factor during migration of hydrocarbons to the gentle flanks.