Basement structure beneath the innershelf off Mahabalipuram to Palar river, east coast of India

Abstract

Magnetic data along three coastal parallel profiles over the innershelf (30-50 m water depth) off Mahabalipuram recorded short wavelength and high amplitude (peak to peak of the order of 200-700 nT) anomalies. Two linear NW-SE trends were delineated from the coastal parallel profiles. Two dimensional modelling of the three sections (P-1 to P-3) indicate folded and faulted magnetic basement beneath the Mahabalipuram shelf. The amplitude of these folds is relatively more at shallow depths (30 m). The folded nature of the basement is still prevalent at greater depths (50-60 m) off Palar river whereas further north towards Mahabalipuram the basement appears to be smooth at greater depths. The results indicate that Palar river is associated with a faulted basement.