Identification and origin of a subsurface ridge on the continental margin of western India

Abstract

Gravity and magnetic studies in the eastern Arabian Sea reveal the presence of subsurface and exposed ridges on and beyond the continental shelf of western India. Distinct patterns of geophysical anomalies are associated with the ridges and also reveal the presence of magnetic polarity reversals. The portions of negative and positive magnetic anomalies of the ridges indicate that the northern part was formed in normal polarity time and the southern part in reversed polarity time. The boundary line of magnetic polarity reversals is marked along 15°10'N. Further it is conjectured that these ridges probably originated because of the movement of the Indian Plate over the Reunion hotspot, during the Late Cretaceous and Early Tertiary.