Super-mobility of hot indian lithosphere

Abstract

The great mobility of the Indian subcontinent during the last 180 million years (~ 9000 km of south-north motion), with an anticlockwise rotation of about 60°, has long been a major puzzle for theorists of plate tectonics. A relative analysis of the available heat flow data, the estimated temperature-depth regime of India and the gravity anomalies, reveals that the Indian lithosphere does not have the characteristics of a typical shield zone and that it has higher radioactivity, smaller viscous drag (decidedly low viscosity of ~10 19 P), lower density and a well-defined low-velocity zone as compared to other shield areas of the world. These factors appear to contribute significantly to the faster northward movement of the thin Indian lithosphere as compared to the almost immobile African plate.