The Bengal Basin is bounded to the west by the
Precambrian Indian Shield Platform, to the east by the Tertiary–
Mesozoic Indo-Burman Folded System, to the north by the Precambrian
Shillong Massif, and extends southward into the present-day Bay of
Bengal. The basinfill comprises a thick sedimentary record (about
20 km) of dominantly continental to marine siliciclastic sediments and
minor carbonate rocks (Reimann, 1993; Gani and Alam, 2004)