Application of Boreholes Redox Mapping Technique for Sandstone-Type Uranium Exploration in Arlit, Niger

Exploration is a key fundamental step in the process of any uranium mining activity. Moreover, a new deposit has been discovered in the context of mine development. The objective of the present research studies is to apply the borehole redox mapping technique as a guide for uranium exploration in the sedimentary environment. The Tarat formation in the study area is the Tarat formation in Arlit area is divided into four units (U4, U3, U2, and U1) such as Tarat Unit4 (U4) consists of reduced gray fine consolidated sandstone alternating clay-silt; Tarat Unit 3 (U3) is composed of coarse to medium sandstone with increasing presence of micro-conglomerate towards the bottom; Tarat Unit 2 (U2) characterized by reduced fine gray sandstone with kaolinitic cement and Tarat Unit 1 (U1) consists of coarse to micro-conglomerate gray sandstone. The results of oxyhydroxides distribution maps show high radiometric accumulation in low oxyhydroxides zones of the Tarat Unit (U4) and Tarat Unit (U3), while the Tarat Unit (U2) and Tarat Unit (U1) show less radiometric accumulation in high oxyhydroxides zones. Therefore, the generalized oxyhydroxide distribution maps of the whole Tarat Formation show that moderate to fewer oxidation zones are suitable for uranium mineralization. In contrast, zones with intense oxidation are poorly mineralized.