Heat flow in the Indian shield

Seventy new heat flow values have been determined for the Indian shield. Th e new sites include 28 from the Archaean Dharwar craton, one from the Prote rozoic Cuddapah basin of southern India, four from the southern part of the Proterozoic Aravalli mobile belt of northwestern India, and 37 from the so uthern part of the Cretaceous-Eocene Deccan Volcanic Province (DVP) of cent ral India. Existing and new data lead to the following inferences: (1) The Dharwar craton, in common with other Archaean cratons is characterized by l ow heat flow values generally ranging from 25 to 50 mW m(-2). (2) The weste rn part of the Cuddapah basin and the DVP to the south of the Son-Narmada-T apti megalineament zone are characterized by low heat flow values in the ra nge 31 to 50 mW m(-2). (3) There is no evidence for thermal transients asso ciated 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 shiel d, the Aravalli mobile belt is characterized by significantly higher heat f low from 56 to 96 mW m(-2). (5) Observations in the Aravalli and Singbhum P roterozoic belts show that some parts of the Precambrian shield are charact erized by high as well as variable heat flow. With no evidence for recent t ectonothermal events the variations in heat flow in the Indian shield can b e mostly explained on the basis of radioactive heat production of the crust al rocks.