Regional estimation of Curie-point depths and succeeding geothermal parameters from recently acquired high-resolution aeromagnetic data of the entire Bida Basin, north-central Nigeria

摘要

A regional estimation of Curie-point depths (CPDs) and succeeding geothermal gradients and subsurface crustal heat flow has been carried out from the spectral centroid analysis of the recently acquired high-resolution aeromagnetic (HRAM) data of the entire Bida Basin in north-central Nigeria. The HRAM data were divided into 28 overlapping blocks, and each block was analysed to obtain depths to the top, centroid, and bottom of the magnetic sources. The depth values were then used to assess the CPD, geothermal gradient, and subsurface crustal heat flow in the basin. The result shows that the CPD varies between 15.57 and 29.62?km with an average of 21.65?km, the geothermal gradient varies between 19.58 and 37.25?°C?kmsup?1/sup with an average of 27.25?°C?kmsup?1/sup, and the crustal heat flow varies between 48.41 and 93.12?mW?msup?2/sup with an average of 68.80?mW?msup?2/sup. Geodynamic processes are mainly controlled by the thermal structure of the Earth's crust; therefore this study is important for appraisal of the geo-processes, rheology, and understanding of the heat flow variations in the Bida Basin, north-central Nigeria.