Mauritania has 80 known uranium mineral occurrences and is the current focus of active exploration for uranium by a number of private companies. Seventeen occurrences have had resource estimates published and can be considered as mineral deposits. Fourteen of these are calcrete-type deposits with a total resource of 138.3 million tonnes at an average grade of 331 ppm U3O8. The three bedrock-hosted deposits are granite hosted vein/shear zone type deposits with a total resource of 46.5 million tonnes at a grade of 248 ppm U3O8.
All of the deposits and the majority of the other uranium occurrences are found in the Paleoproterozoic Rgueïbat Shield in areas underlain by the Cortege de Yetti, the Complexe de Tmeïmichatt Ghallamane and the Complexe d'Adam Esseder. This area is also visible in the PRISM airborne radiometric data as an extensive >4 ppm equivalent uranium anomaly.
Uranium occurrences are also reported in the Tasiast-Tijirit Terrane of the Archean Rgueïbat Shield, the Mauritanide Belt, and the Coastal Basin. Geologic environments permissive for eight types of uranium deposits are recognized in Mauritania. These deposit types include: calcrete, granite-hosted vein/shear, alkaline intrusive, unconformity-associated, quartz pebble conglomerate, phosphate, sandstone, and red bed-type uranium deposits.
