Applying satellite imagery and data processing enhancements for geological mapping in the southeast area of the Kerdous inlier

Remote sensing has become an essential tool in geological investigations, particularly for lithological mapping and discrimination of rock units. It is especially effective for studying inaccessible terrains and for acquiring detailed geological information over large areas. In this study, Landsat 8 Operational Land Imager (OLI) multispectral data were employed to extract lithological and hydrothermal alteration information using a set of advanced image-processing techniques. These include band ratios (BR), principal component analysis (PCA), correlation coefficient (CC), and optimal index factor (OIF). False color composites using bands 7, 5, and 1, selected band ratios (4/2, 5/6, and 6/7), and principal component images (PC5, PC2, and PC1) were applied to enhance and analyze the spectral characteristics of the lithological units in the study area. Furthermore, hydrothermal alteration indices were used to delineate zones enriched in metallic elements. The remote sensing results were integrated with geological field observations and analyzed within a Geographic Information System (GIS) environment to perform a multi-criteria characterization of mineralized areas. The findings demonstrate that remote sensing techniques significantly improve and update existing geological maps of the region. Key geological contacts, as well as mineralized dykes and veins of economic interest, were successfully identified using Landsat 8 OLI multispectral imagery. Field verification and geochemical sampling carried out by the Ministry of ONHYM during cartographic missions confirmed the accuracy and reliability of the remote sensing interpretations.