Remote Sensing-Based Mapping of Gold Mineralization in the Donko Area, Northwestern Nigeria

Gold mineralization in the Donko area of the Zuru Schist Belt is associated with lithological, hydrothermal alteration and structural features that can be effectively investigated using multispectral remote sensing. This study employed Landsat 9 Operational Land Imager (OLI) data to delineate lithological units, identify hydrothermal alteration signatures and characterize surface lineaments associated with gold-mineralization potential. Cloud-free Level-2 Landsat 9 OLI imagery acquired on 17 February 2024 along Path 190/Row 052 was processed using ENVI 5.3. The processing involved layer stacking, spatial sub-setting, false-colour composite (FCC), band-ratio analysis and selective Crosta principal component analysis (PCA), followed by automated and manual lineament extraction and GIS-based spatial analysis. The 7-4-3 FCC effectively enhanced lithological contrasts and facilitated discrimination of schist, gneiss, quartzite and other basement rock units. Band ratios of 4/2, 6/5 and 6/7 enhanced iron-oxide/hydroxide, ferrous/silicate and hydroxyl/carbonate mineral responses, respectively, with hydroxyl/carbonate signatures notably concentrated around the known gold-mineralized area. Crosta-PCA further enhanced the spectral responses of iron-oxide, hydroxyl/carbonate and ferrous minerals, providing complementary evidence of hydrothermal alteration. Lineament analysis revealed relatively high densities in the northeastern and central parts of the study area, with dominant NE–SW and NW–SE orientations and subordinate N–S trends. Integration of lithological, alteration and structural information identified areas where alteration signatures coincide with concentrated lineaments as the most favourable remote-sensing targets for gold mineralization. The results demonstrate the effectiveness of Landsat 9 OLI for reconnaissance-scale mineral exploration in the Donko area and provide targets for subsequent geological and geochemical validation.