Magnetic expression of some major lineaments and cretaceous quiet zone in the Bay of Bengal

Abstract

Magnetic data over the eastern continental margin of India and adjacent Bengal fan demarcate two major lineaments. A high amplitude N - S trending lineation of the Cauvery offshore Basin corresponds to the offshore fragment of the 80 degrees Elineament recorded onland. A N - S lineation of very high amplitude anomaly off Chilka lake considered as the possible northward extension of the 85 degrees E ridge delineated, hitherto in Bengal Fan. A subduced magnetic anomaly zone is demarcated seaward of the continent-ocean boundary (COB) in the Bengal Fan. Over the northern Bengal Fan this zone is delineated east of 85 degrees E lineation. This quiet zone might have evolved during the Early Cretaceous period of normal magnetic polarity between MO and 34 (120 - 84 Ma) anomalies