Geochemistry and Petrogenesis of Basic Dykes of Agali Area, Palghat District, Kerala

Abstract

A basic dyke swarm trending ENE-WSW traverses the Agali area of north-central Kerala. The geochemistry of these dykes suggests that they are transitional in character between continental and oceanic basalts. and are akin to one of the magmatic phases of the Deccan volcanics. They have been derived from a tholeiitic magma generated by partial melting of a heterogeneous mantle containing minor amounts of phlogopite and apatite. Fractionation of clinopyroxene. magnetite and plagioclase is indicated. The present study supports one of the earlier suggestions that these dykes are related to the rifting of the western continental margin of India.