Role of Adakitic Magmatism and Subduction in Gold Endowment of Dharwar Neoarchaean Greenstone Belts, India

Acid volcanics found in auriferous greenstone belts of the Dharwar Craton are rhyolites, adakitic rhyohtes and high silica adakites Adakites are compositionally similar to TTG and characterized by high Na^/K^O, depleted MgO, Cr, Ni, Y and Yb. The adakitic melts were most probably generated by the partial melting of the basaltic slab below a mantle wedge LILE and LREE enriched IAB are the dominant volcanic members of the greenstone belts IAB of the greenstone belts were generated from partial melting of the mantle wedge under the influence of slab derived fluids. The wedge derived IAB and slab derived adakites were deformed and metamorphosed to generate fluids responsible for the gold endowment of these belts. Rhyohtes and possibly rhyohtic adakites were generated by the melting of the sialic continental crust forming top of the descending slab. Identification of adakites in auriferous greenstone belts strengthens the genetic link between adakite magmatism, subduction and Neoarchaean gold endowment.