Uranium mineralisation in the mesoproterozoic quartzites of Cuddapah basinin Gandi Area, Cuddapah District, Andhra Pradesh : A new exploration target for uranium

Significant uranium occurrences are discovered recently for the first time in the Gulcheru Quartzite of Papaghni Group of Cuddapah Supergroup near Gan di, east of Papaghni river, Cuddapah District, A.P. Mineralisation is assoc iated with an E-W fault. Friable whitish to light pink quartzite is the mai n host rock of uranium. Mineralisation occurs in the form of lensoidal bodi es having dimensions of 20 - 200 m x 2 - 10 m in an E-W fault scarp section , over 2 km in length. Dip section is also mineralised. Samples have reveal ed anomalous concentrations of uranium, up to 1.441% U3O8 with negligible t horium. Concentration of Ni (< 25 to 1033 ppm), Mo (< 25 to 643 ppm), Pb (3 3 to 1515 ppm) and Cu (< 25 to 170 ppm) points to the economic potentiality of the area. Petrological studies have identified uranium minerals such as pitchblende, uraninite and coffinite as fracture fillings and disseminatio ns in the chlorite-sericite matrix of quartzite. The associated ore mineral s are chalcopyrite, arsenopyrite, pyrite and limonite. These findings have important implications in the selection of new exploration targets for uran ium in the basal beds of Cuddapah Supergroup unconformably overlying the fe rtile granitoid basement in the Eastern Dharwar Craton occurring in the sou thwestern part of Cuddapah basin.