Assessment of Sustainable Geothermal Heat Flow Potential in Parts of the Nigerian Benue Trough for Green Energy Development

Abstract

The growing demand for sustainable energy has increased interest in the Benue Trough as a potential geothermal resource region due to its tectonic structures, intrusive bodies, and elevated heat flow signatures identifiable through aeromagnetic investigations. This study evaluates the sustainable heat flow potential in parts of the Benue Trough for geothermal green energy development using aeromagnetic data from the Nigerian Geological Survey Agency (NGSA). Data processing involved reduction to the magnetic equator, upward continuation, regional-residual separation, and spectral analysis using Geosoft Oasis Montaj, ArcGIS, QGIS, and Golden Software Surfer. Results revealed significant geological structures and magnetic anomalies linked to geothermal and mineral resources. TMI and RTE maps identified high magnetic intensity zones around Ankpa, Gboko, and Igumale. Spectral analysis indicated shallow magnetic sources (0.3–3 km) and deeper sources (4–8 km, averaging 5.8 km), while Curie Point Depth estimates ranged from 8–15 km. Geothermal gradients varied between 40°C/km and 73°C/km, with heat flux values of 100–183 mW/m², confirming strong geothermal potential. High heat flow zones, including Abakaliki, Otukpo, and the Ejekwe–Ogoja structural zone, showed extensive faults, fractures, and lithological boundaries favourable for geothermal exploration. Major fault systems and intrusive bodies such as dykes, sills, and batholiths were identified as possible heat transfer pathways and heat sources, while vector mapping aligned magnetic anomalies with structural trends indicative of active geothermal reservoirs. These findings highlight promising locations for geothermal drilling, subject to further geophysical validation.