MAGNETIC EXPRESSION OF SOME MAJOR LINEAMENTS AND CRETACEOUS QUIET ZONE IN THE BAY OF BENGAL

Magnetic data over the eastern continental margin of India and adjacen t Bengal fan demarcate two major lineaments. A high amplitude N-S-tren ding lineation of the Cauvery offshore Basin corresponds to the offsho re fragment of the 80 degrees E lineament recorded onland. A N-S linea tion of very high amplitude anomaly off Chilka lake considered as the possible northward extension of the 85 degrees E ridge delineated, hit herto in Bengal Fan. A subdued magnetic anomaly zone is demarcated sea ward of the continent-ocean boundary (COB) in the Bengal Fan. Over the northern Bengal Fan this zone is delineated east of 85 degrees E line ation. This quiet zone might have evolved during the Early Cretaceous period of normal magnetic polarity between MO and 34 (120-84 Ma) anoma lies.