Offshore Structural Trends from Magnetic data over Cauvery Basin, East Coast of India

Detailed analysis of magnetic and bathymetric data over shelf and slope regions of Cauvery basin, east coast of India. between Mahabalipuram and Vedaranyam demarcated three major offshore lineaments trending N-S, NE-SW and E-W. The N-S lineation has been interpreted as due to dyke intrusions. NE-SW lineament reflects the offshore extension of a major basement depression, viz., the Pondicherry depression. E-W lineation, south of Porto Novo reveals a basement high suggesting the seaward extension of Kumbakonam ridge within the Pondicherry depression. The present analysis gives mosaic of a deep seated graben block flanked by rift related volcanic intrusives over the shelf region of the basin.