Two late Cretaceous mafic dykes with an ENE strike that is orthogonal to the west coast of India and located nearly 200 km inland around Huliyardurga, Karnataka state, yield 40Ar-39Ar plateau ages of 90.0¿1.0 and 87.5¿0.9 Ma. These Fe-Ti-enriched tholeiites are essentially co-eval with at least four other igneous suites widely scattered in southern India, namely; the south and north Kerala dykes, the Agali-Anaikatti dykes of central Kerala-Tamil Nadu and lavas of St Mary islands off the west coast of India. The Karnataka Cretaceous dykes are also co-eval and compositionally very similar to the Fe-Ti-enriched tholeiitic lavas and dykes around Mananjary, a major phase of Late Cretaceous magmatism along the eastern rifted margin of Madagascar which are believed to be products of the Marion hot spot that extruded at ~88 Ma, synchronous with the India-Madagascar break up event. The age and compositional similarities between these Late Cretaceous magmatic rocks from India and Madagascar constitute a clear evidence for extension of the thermal manifestations deep into the Indian peninsula. ¿ 2001 American Geophysical Union