Heat flow in the Indian shield

Seventy new heat flow values have been determined for the Indian shield. The new sites include 28 from the Archaean Dharwar craton, one from the Proterozoic Cuddapah basin of southern India, four from the southern part of the Proterozoic Aravalli mobile belt of northwestern India, and 37 from the southern part of the Cretaceous-Eocene Deccan Volcanic Province (DVP) of central India. Existing and new data lead to the following inferences: (1) The Dharwar craton, in common with other Archaean cratons is characterized by low heat flow values generally ranging from 25 to 50 mW m(-2). (2) The western part of the Cuddapah basin and the DVP to the south of the Son-Narmada-Tapti megalineament zone are characterized by low heat flow values in the range 31 to 50 mW m(-2). (3) There is no evidence for thermal transients associated with the K-T Deccan volcanism on the present-day heat flow regime in the southern part of the DVP. (4) In contrast to the southern Indian shield, the Aravalli mobile belt is characterized by significantly higher heat flow from 56 to 96 mW m(-2). (5) Observations in the Aravalli and Singbhum Proterozoic belts show that some parts of the Precambrian shield are characterized by high as well as variable heat flow. With no evidence for recent tectonothermal events the variations in heat flow in the Indian shield can be mostly explained on the basis of radioactive heat production of the crustal rocks.