Estimation of Curie point depths and succeeding geothermal parameters from High-Resolution Aeromagnetic Data of the younger granite complexes of Jos and environs Northcentral Nigeria

Abstract

A regional estimation of Curie point depths and succeeding geothermal gradients and subsurface crustal heat flow has been carried out from the spectral centroid analysis of High-Resolution Aeromagnetic Data of Jos and environs in north central Nigeria. The High-Resolution Aeromagnetic Data were divided into nine 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 evaluate the Curie point depth, subsurface crustal heat flow of the area and geothermal gradient. The estimated Curie point depth value varies from 9.70 to 17.79 km with an average value of 13.84 km. The value of heat flow ranges from 82 to 149 mWm^-2 with an average value of 109 mWm^-2 whiles the value of geothermal gradient ranges from 32.60 to 59.79 ℃km^-1with an average value of 43.52 ℃km^-1. Negative relationship was observed between the Curie point depth and heat flow within the study area. The Curie point depths have a small relationship with topography due to isostatic compensation and rifting. The Digital Elevation Model map of the study area show elevation values that ranges between 218.908 to 1404.595 m. This study is important for appraisal of the geo-processes, geology, and understanding of the heat flow variations in the Younger Granite Complexes of the study area.