EVOLUTION OF THE CONTINENTAL-MARGIN OF WESTERN INDIA - NEW EVIDENCE FROM APATITE FISSION-TRACK DATING

Apatite fission-track dating in southwestern India yields Middle Trias sic to Middle Jurassic ages that correlate with the breakup of eastern Gondwanaland and Africa. The later India-Madagascar split is not reco rded in the apatite ages. The apatite ages are not a reflection of the rmal events in the present location of this region but are associated with uplift and erosion in the Upper Paleozoic/Early Mesozoic eastern Gondwana-Africa separation. Track length measurements indicate that co oling through the 100-degrees-C isotherm began in the Upper Paleozoic. Time-temperature modeling suggests that a period of slow cooling duri ng the Mesozoic was followed by relatively rapid cooling to the presen t.