Possible extensions of the Narmada-Son lineament towards Murray Ridge (Arabian Sea) and the eastern syntaxial bend of the Himalayas

Geophysical data contiguous with the Narmada-Son lineament suggests its possible extension westward into the Arabian Sea and eastward up to the Shillong Plateau. The airborne magnetic anomaly map of the north Arabian Sea delineates a linear trend of magnetic anomalies in line with the Narmada-Son lineament. This group of magnetic anomalies, spreading over 20°N to 22°N, starts near the west coast of India at 21°N, 69°30′E and extends to the Murray Ridge. The tectonic feature represented by this group of magnetic anomalies is buried by a thick layer of sediments. This westward extension of the lineament is also reflected in the average Bouguer gravity anomaly map of the Indian Ocean. Towards the east, the gravity and magnetic data delineate a subsurface linear tectonic feature which extends in line with this lineament to the eastern syntaxial bend. These various geophysical signatures further suggest the lineament to be a typical rift-like structure. The tectonic implications of the lineament, which extends from the western to the eastern margins of the Indian plate, is discussed.