STRUCTURAL LINEAMENTS FROM THE MAGNETIC ANOMALY MAPS OF THE EASTERN CONTINENTAL-MARGIN OF INDIA (ECMI) AND NW BENGAL FAN

Three major structural lineaments are inferred from the magnetic and b athymetry data collected over the eastern continental margin of India (ECMI) and NW Bengal Fan, covering the area between 10-degrees 55'N to 20-degrees 15'N and 80-degrees-E to 88-degrees-E. Analysis of magneti c data associated with these trends suggests that (1) trend I, located at the foot of the continental slope (around 3000 m water depth) repr esents the ocean-continent boundary (OCB) of ECMI, (2) trend II repres ents the northern extension of 85-degrees-E ridge, abutting the contin ental shelf off Chilka Lake and (3) trend III, located over the contin ental shelf/slope between Visakhapatnam and Paradip represents a folde d (ridges and depressions) nature of the continental basement. The stu dy also reveals the occurrence of dyke intrusions within the continent al crust landward of OCB, which might be related to the rift-phase vol canism along the ECMI.