GEOCHEMISTRY AND PETROGENESIS OF THE CHAMPAWAT GRANITOIDS OCCURRING AROUND DHUNAGHAT, DISTRICT PITHORAGARH, UTTAR-PRADESH, INDIA

Early Cambrian Champawat granitoids from Dhunaghat area, emplaced between medium-to high-grade metapelites of the Saryu Formation and low-grade metapelites of the Gumalikhet Formation of the Almora Group, show wide variations in their modal and chemical composition, ranging from granodiorite lo granite. Biotile-rich mafic enclaves within the granitoids may represent restite, possibly modified by metasomatism. Chemical data for the calc-alkaline Champawat granitoids show some degree of fractional crystallization, although processes such as restite unmixing and different degree of melting may also have been important for the observed variation trends. The Champawat intrusives are also characterized by enrichment of Y, Zr, Th, U, Nb, La, Ce, Pr and Nd and show affinities with ''A'' - type (anorogenic) granites.