Abstract

The controversial subject of Continent to Oceanic Boundary (COB) off the western continental margin of India is addressed through a study of gravity and magnetic data. Published free-air gravity and magnetic anomaly data along with a few regional scale magnetic anomaly profiles acquired by ONGC constitute the database for the study. Analysis of gravity data indicates that the COB is located near the shelf edge. A set of seafloor spreading-type lineations roughly parallel to the west coast and running along its entire length are observed in the composite magnetic anomaly map. Comparison with a simple synthetic seafloor spreading magnetic anomaly profile indicates that these lineations are probably generated by seafloor spreading just to the west of shelf edge. The study brings out a simple scheme of one-stage breakup of India from Madagascar and Seychelles starting from about 89 Ma without ridge jumps. Consequently, there is a necessity for re-examination of geological events hitherto associated with India