Interpretation of aeromagnetic data for estimation of Curie point depth in Sokoto Basin, Nigeria

摘要

This research studied the estimation of the Curie point depth isotherm using aeromagnetic data across Sokoto Basin, Northwest, Nigeria. The study area lies within the longitudes of 3-7 degrees east and latitudes of 10-14 degrees north. The residual-regional separation was carried out on the total magnetic intensity using polynomial fitting of the second order. The residual map that formed the basis for analysis and interpretation was divided into 30 spectral blocks. Hence, the log of the spectral energies was plotted against the frequency using a spectral program plot developed with Matlab. The obtained results of centroid depth and depth to the top boundary were used in estimating the Curie point depth isotherm, which serves as the depth at which the crust and uppermost mantle magnetic materials cease to be magnetic. Interestingly, the results obtained from the spectral analysis of the study area, where an average depth to the top boundary of 2.2 6 km was obtained, indicated a good spot for hydrocarbon potential. The Curie point depth within the study area varied between 5.96 and 74.29 km with an average depth of 18.99 km. Impliedly, the results obtained from the Curie point depth isotherm indicated a good source of geothermal potential in the study area.