Investigating Subsurface Thermal Regimes Using High-Resolution Aeromagnetic Data in the Upper Benue Trough, Northeastern Nigeria

Abstract: High-resolution Aeromagnetic data were processed using Oasis Montaj software to produce residual magnetic anomaly maps of the study area, from which the Curie point depth was determined for heat flow and geothermal gradient assessment. The Curie depth values ranged from 16.6 km to 23.05 km, with an average of 17.55 km. Using a thermal conductivity of 2.5 Wm⁻¹°C⁻¹ and a Curie temperature of 580°C, calculated geothermal gradients ranged from 25.16°C/km to 35.04°C/km, and heat flow values varied between 62.9 and 87.6 mWm⁻². These thermal parameters indicate mostly tectonically stable conditions with localized geothermal anomalies, particularly around Dukku, Wade, Karim Lamido, and Jabieb, coinciding with known geothermal springs and attributed to crustal thinning and magmatic intrusions. The spectral analysis approach Based on magnetic anomaly wavelength decomposition,] provides a reliable framework for estimating subsurface thermal structures. The study supports the potential for geothermal energy exploration in the area. It highlights the utility of combining magnetic and thermal modelling for geothermal resource assessment, especially where direct temperature measurements are sparse. Further investigations, including geochemical and drilling studies, are recommended to validate geothermal prospectivity and support sustainable energy development in the region.