A PAN-AFRICAN THERMAL EVENT IN SOUTHERN INDIA

U-Pb zircon data from five igneous suites confirm previous studies tha t demonstrated widespread Pan-African magmatism in the Granulite Terra in of southern India. Ages determined here are similar to 560 Ma for t he Peralimala Granite and similar to 555 Ma for the Kalpatta Granite, both north of the Palghat-Cauvery lineament, and similar to 585 Ma for a charnockite in the Cardamom massif south of the lineament. Zircon f rom a pegmatite in the Kerala khondalite belt at Melankode yields an a ge of 512 Ma. Resetting of zircons in the 2500-Ma Arsikere Granite of the western Dharwar craton probably occurred at similar to 450 Ma. The se ages and the concentration of Pan-African granitic magmatism around the Indian portion of a broad region of granulite-facies metamorphism in East Gondwana demonstrates generation of a restricted area of high temperature either above a rising plume or a zone of rifting. Mantle- derived fluids continued to move upward through the crust of southern India for at least 100 m.y. after the peak of magmatism, and the entir e region was still cooling at 400 Ma. Copyright (C) 1996 Elsevier Scie nce Ltd