Geology of Northeastern Nigeria and its prospects for geothermal energy: A Review

Geothermal energy offers a sustainable and environmentally friendly alternative to conventional fossil fuels, yet remains underexplored in many developing regions, including Nigeria. This study investigates the geothermal energy potential of Northeastern Nigeria through geological analysis and digitization of existing geological maps using Geographic Information Systems (GIS). The study area, located predominantly in Bauchi State and parts of Plateau and Gombe States, is bounded by latitudes 9°30′N to 11°00′N and longitudes 9°00′E to 11°00′E. It encompasses diverse lithological units ranging from the Precambrian Basement Complex to Cretaceous and Tertiary sedimentary formations, as well as Tertiary–Quaternary volcanic rocks and intrusive granitic complexes. Key geothermal indicators identified include hot springs, tectonic basins, uranium mineralization, and radiogenically enriched granites associated with elevated heat flow. Digitization involved georeferencing scanned analog geological maps, manual vectorization of lithological and structural features, and integration of spatial data into a GIS geodatabase. Attribute information was assigned based on map legends and standardized geological symbology, enabling further spatial analysis. The presence of Younger Granite ring complexes enriched in heat-producing elements (U, Th, K) and the occurrence of anomalously high heat flow values (70–90 mW/m²) suggest a significant geothermal gradient, especially in structurally deformed zones. This study provides foundational digital geological data and highlights key zones with high geothermal prospectivity. The results support future geophysical exploration and policy development toward sustainable energy exploitation in Nigeria’s northeastern region.