A SEDIMENT THICKNESS MAP AND TECTONICS OF THE DISTAL BENGAL FAN

A sediment thickness map for the Distal Bengal Fan between 9-degrees-N to 6-degrees-S and 78-degrees-E to 98-degrees-E is compiled on the ba se of single-channel seismic reflection profiles. General N-S and SE-N W structure strikes dominate, though the Ninetyeast Ridge and adjacent Central Indian and Cocos Basins have individual isopach patterns. The Ninetyeast Ridge, the 85-degrees-E Ridge and the Aphanasy Nikitin Sea mounts, ARE generated in the gigantic old deep-seated N-S fracture zon es, as well as the Comorin Ridge and the Wharton Ridge are clearly exp ressed in the map. More young dislocations, including the well known L ate Miocene intraplate deformation of the Central Indian Basin lithosp here, are revealed significantly worse in the sediment isopachs. In ge neral, the sediment distribution is controlled by interrelation of two genetic depositional sequence: progradational onlap fill sequence (te rrigenous turbidits) and aqueous sequence (pelagic sediments).