Regional marine geophysical studies of the south western continental margin of India

Abstract

Integrated bathymetric, gravimetric, magnetic and multichannel seismic reflection studies were carried out on the south western continental margin of India along three regional profiles. The study area lies between 60 m and 4900m isobath and cover from east to west, the shelf edge, Kerala-Laccadive graben, the Laccadive ridge and the abyssal plains. A preliminary study of the data revealed that i) the acoustic basement in the shelf margin basin is in the form of ridge complex which widens and deepens towards south and is overlain by sedimentary sequence of maximum thickness of about 2.5 sec. of two way travel time. The Laccadive ridge system is characterised by a generally raised acoustic basement mantled by transparent sediments. Further the morphology of the acoustic basement over the Laccadive ridge system is governed at places by steep scarps and at places by volcanic intrusives reflected by large amplitude magnetic anomalies. The crest of the ridge is associated with a graben like feature