CUDDAPAH BASIN: A STORE-HOUSE FOR URANIUM DEPOSITS: The Proterozoic Cuddapah basin has been well known for a variety of mineral resources: diamond, barite, asbestos, copper, lead, limestone and Cuddapah slabs. 25% of the world's barite resources are present within the basin. Uranium exploration searched the quartz-pebble-conglomerate type uranium mineralisation which had dominated the world uranium supply at that time. However, the basal Gulcheru conglomerates at the base of Cuddapah basin were found to be thoriferous. Subsequent exploration in the late 1980's, brought out significant uranium mineralisation in dolostone. A significant breakthrough was achieved in early 1990's when uranium mineralisation was located along the unconformity between Srisailam Formation of Cuddapah Super Group and the basement granites, thereby establishing in India, for the first time, the presence of unconformity related uranium mineralisation - a category considered most potential world over.