Shelf edge progradation: An example from Early Cretaceous to Recent based on a seismic sequence stratigraphic framework in the Bengal Basin

This study reconstructs the stratigraphic and tectonostratigraphic frameworks of the Bengal Basin by integrating outcrop geological observations, 2D seismic profiles, well logs, core samples, sedimentological, geochemical, and radiometric dating data that are tied to global eustatic sea-level variations. Sequence stratigraphic analysis of the basin allowed the identification of three megasequences, seven seismic sequences, and twelve regional stratigraphic markers spanning from the Late Cretaceous to Holocene. The shelf-edge progradation analysis from Early Cretaceous to Recent reveals the Bengal Basin’s evolution from Gondwana rifting to foredeep subsidence and deltaic progradation. Controlled by tectonics, eustasy, and sediment supply, the Ganges-Brahmaputra Delta and the Bengal Fan established a complex stratigraphic framework with significant petroleum potential. Petroleum prospectivity is concentrated in Paleocene to Pliocene sandstones having intraformational shales as seals. Structural trapping configurations include horst-graben fault blocks and fold-belt closures, and stratigraphic trapping configurations such as stratigraphic pinchouts and channelized deposits. Seismic attribute analysis combined with well and core data emphasizes on the potential of underexplored Miocene-Pliocene slope-fan and canyon-fill turbidites as emerging frontier targets. Comparative evaluation of the Bengal Basin with the Krishna-Godavari Basin highlights greater structural complexity, thicker sedimentary pile, and diverse play types, suggesting it’s higher hydrocarbon potential. However, exploration continues to face significant challenges, as this study is based only on qualitative analysis constrained by limited seismic coverage and the low resolution of older datasets. Overall, the Bengal Basin represents a tectonically dynamic and sedimentologically complex petroleum province, whose stratigraphic framework and depositional history are crucial for guiding future exploration strategies.