Lithological, structural, and alteration mapping of uraniferous granitoid using Landsat 8, in the oriental part of the Reguibat shield, northern Mauritania

The efficacy of remote sensing techniques for mineral exploration has been proven through several geological investigations. Therefore, this study used remote sensing techniques to delineate uranium prospective zones in the oriental part of Reguibat shield. This region is desert, flat and uncovered by vegetation and presents suitable characteristics for use of satellite images. Radiometric calibration, atmospheric correction, colour composite, principal component analysis (PCA), lineament extraction and band ratios were the main methods performed for the pre-processing and the processing of Landsat 8 OLI images. The findings of the current study revealed lithological units dominated by felsic rocks in association with metasediment, highlighted using band composite (bands 7, 5 and 3, then 7, 2, and 1, in RGB), PCs (PC1, PC2, and PC3) and band ratio (7/5, 5/4, and 6/7 in RGB). The lineament extraction and analysis indicated major deformation trending NNE-SSW affecting geological units of the area. The prospective uraniferous zone delineated showed a spatial distribution in relation with an identified shear zone which suggests a reasonable structural control of the mineralization. The results from this study were validated with existing data from previous map and ground truthing from fieldwork, and they showed high level of agreement. The result of this study further demonstrated the applicability of Landsat 8 OLI as suitable lithological mapping tool in the desert areas. The methodology employed in this research has wide-ranging applications in the identification and delineation of potential uranium-rich regions using remote sensing techniques. For uranium exploration purpose, this approach can be effectively utilized in various other regions to delineate new uraniferous area within the Reguibat shield, as well as in arid and semi-arid areas across the globe.