Ganges cone: A wide angle seismic reflection and refraction study

Abstract

A seismic wide angle reflection and refraction survey on the Ganges Gone sediments has indicated an overall layered sediment sequence. Surface layers have indicated depositional features associated with submarine river channels. Structural highs suggest that the 90°E Ridge continues farther north of the present topographic relief, buried under the Ganges Cone sediments. Nine distinct values of velocities have been found throughout the region, each representing one layer. The average values of these range between 2.05 and 6.22 km/sec, and the layers vary in thickness. The average total thickness of the sediment up to the 6.22-km/sec layer is estimated at 7.87 km. These observations have been compared with oceanic and continental models. Velocity versus depth relation indicates a linear increase of velocity with depth with a gradient of 0.62 sec−1. Comparison of sediment thickness with a DSDP site on the Ganges Cone suggests that the base of the sediment may extend into Upper Cretaceous.