Assaying the Geothermal Energy Resource Potential of Gombe State in North-Eastern, Nigeria from Aeromagnetic Survey

Abstract

A geothermal investigation of the whole of Gombe State in northeastern Nigeria has been done from a 2D spectral analysis of recently acquired high resolution aeromagnetic data as a means to elucidate likely concealed geothermal reservoirs in the state. The aeromagnetic data were divided into 20 overlapping blocks of 180 x 180 Km and each block analysed to estimate the Curie-point depths and ensuing geothermal gradient and heat flow isotherms. The results revealed Curie-point depths ranging from 20.03 to 29.83 Km with an average of 24.92 Km while geothermal gradients range between 19.44 and 28.69 ^oC/Km with an average of 23.60 ^oC/Km and an average value of 58.69 mW/m2 (i.e. 48.61 – 72.39 mW/m²) for heat flow. The results demonstrate that the entire State is dominated with thick crustal layer (above 15 Km) and heat flow that is less than both the global average of 87 mW/m2 and accepted value of 80 - 100 mW/m2 for anomalous geothermal conditions. Therefore, this study deduces that Gombe State may not have traces of anomalous geothermal settings, having shown no zone of considerable crustal attenuation and elevated heat flow. Even so, the study contributes to understanding of the thermal state of the lithosphere and regional heat flow variations of the geological formation housing the state.