Integrated Remote Sensing and Field Validation for Geological and Structural Mapping of Neoproterozoic Basement Rocks in Northern Somalia

The Northern Somali Basement (NSB) represents a critical segment of the East African Orogen (EAO); however, it remains poorly mapped owing to a lack of geological investigations. This study employs an integrated approach, combining Landsat 8 Operational Land Imager (OLI) multispectral data with systematic field investigations, to investigate the geological and structural framework of the Milxo area in northern Somalia. Image enhancement techniques, including principal component analysis (PCA) and specialized band ratios (Sabin’s and Kaufmann’s), were used to delineate lithological units and hydrothermal alteration zones. The results successfully discriminated younger granite intrusions from the surrounding Inda Ad complex metasediments, revealing that these granites occur as several isolated, smaller outcrops rather than the two large plutonic bodies depicted in legacy maps. Structural analysis identified a complex network of NE-SW and NW-SE trending lineaments and a major anticlinal fold, reflecting intense deformation during the Pan-African Orogeny. Fieldwork investigations further validated these findings, documenting phaneritic granitic textures, angular unconformities, and quartz veins. Notably, localized copper mineralization was observed along the identified fracture systems, suggesting strong structural control over mineral deposition. These results illustrate that combining satellite-based remote sensing with field validation offers an effective and economical method for geological mapping and mineral exploration in under-researched areas like Somalia.