Estimation of Curie Depths, Heat Flow, Geothermal Gradient of Biu Plateau Basalts and Environs, North Eastern Nigeria

This study analyzes the geothermal framework of the Biu Plateau Basalts and their surrounding regions in northeastern Nigeria using aeromagnetic data interpretation. Through the application of Oasis Montaj software, key thermal parameters—including Curie point depth (CPD), geothermal gradient, and surface heat flow—were estimated to evaluate the crustal thermal structure. The derived CPD values range between 4 km and 21 km, with shallower depths occurring in the northeast and progressively deeper ones toward the southeast. These variations suggest that the Curie isotherm may coincide locally with the Moho discontinuity, reflecting differences in magmatic activity and tectonic evolution within the area. Calculated geothermal gradients vary from 25°C/km to 125°C/km, while heat flow values lie between 60 mW/m² and 320 mW/m². Zones in the northeast exhibiting high heat flow (up to 320 mW/m²) and shallow Curie depths (~4 km) indicate significant geothermal prospects. Conversely, the southeastern sector, characterized by deeper Curie depths (~21 km) and lower heat flow (~60 mW/m²), may be influenced by isostatic adjustment processes. The study identifies an inverse correlation between Curie depth and heat flow, while the geothermal gradient maintains a direct relationship with heat flow. Overall, the findings confirm that aeromagnetic data provide an effective approach for locating geothermal anomalies in areas with scarce subsurface thermal data. The spatial distribution of Curie depths, heat flow, and geothermal gradients further underscores active tectono-thermal interactions, marking the southeastern portion of the Biu Plateau as a promising target for future geothermal exploration and development.