Geological and Geomorphological studies have lead to the belief that the ancient Indian shield extends upto the west of Laccadive Islands. The Murray Ridge is believed to be a continuation of the geoanticlinal structure of West Pakistan into the Gulf of Oman. Geophysical investigations carried out during the International Indian Ocean Expedition Programme have proved that the Laccadive-Maldive ridge system as of volcanic type rather than a continental relic and the Murray Ridge as the continuation of Carlsberg Ridge in North-Northeast direction.

The presence of thick Deccan Trap material near Bombay Coast and the north-south alignment of the Laccadive-Maldive ridge system have lead to the presumption that the volcanism which originated in the Chagos area continued into the continent producing the ridge system and the Deccan Traps as well.

This paper summarises the results of recent geophysical studies in the Arabian Sea including those obtained by the author off the West Coast of India. Based on these results, the crustal structure and the extension of the ocean bottom features of the Arabian Sea along the west coast of the Indian sub-continent are discussed.