GEOLOGICAL ENVIRONMENT OF THE SANDSTONE-TYPE URANIUM DEPOSIT, DOMIASIAT AREA, KHASI HILLS DISTRICT, MEGHALAYA, INDIA
SUNIL KUMAR1, RAJENDRA SINGH2, R. BAHUGUNA3; B. SENGUPTA2 AND RAVI KAUL 4
Atomic Minerals Division
Department of Atomic Energy
1Bangalore-560 072, 2New Delhi-110 066, 3 Jaipur-302 004, and 4 Hyderabad-500 016
Abstract
The sandstone-type uranium deposit at Domiasiat is mainly confined to the proximal, braided, palaeochannels developed under piedmont-type environment during the Upper Cretaceous period. The rich uranium concentration in the grey coloured, medium- to coarse-grained, and at places cross-bedded sandstone, owes itself to a combination of favourable factors, such as, a uranium-rich provenance (South Khasi granitic batholith); development of basement highs and lows and deposition in small basinal depressions; abundance of reductants in the form of organic matter and possibly pyrite; and the gentle dips of the host sandstones. A syndiagenetic origin is postulated for the uranium mineralization.