2. General geology
The Bengal Basin lies at the confluence of the Ganges, Brahmaputra
and Meghna rivers (Fig. 1). The basin has evolved since the Early
Cretaceous, following the breakup of Gondwana, and sedimentation has
been continuous ever since (Banerji, 1981; Gani and Alam, 2004).
Bangladesh occupies the greater part of the Bengal Basin (Uddin and
Lundberg, 2004). 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)