Characteristics of basement granitoids and their role on uranium mineralisation in and around southwestern margin of Cuddapah Basin, Andhra Pradesh

Different types of uranium mineralisation in the environs of Cuddapah Basin show temporal and spatial association with uraniferous basement granitoids (Closepet Equivalent) exposed in its southern and southwestern margin. Geochemical studies of these granitoids show that these are generally peraluminous and strongly differentiated with uranium concentration from 10 to 90 ppm. Uranium mineralisation (in terms of grade and thickness) in the granite-hosted, fracture- controlled type and in the Cuddapah sediments is pronounced in areas where basement rocks have more volume of these strongly differentiated uraniferous granitoids. In contrast, uranium mineralisation is of low grade and thickness where basement is represented by Peninsular gneisses. (author)