Determination of Curie Depth, Geothermal Energy and Heat Flow in Chad Basin Northeast Nigeria Using Spectral Analysis of Aeromagnetic Data

This study attempts to estimate the Curie point depth (CPD), geothermal energy, and heat flow in the Chad Basin northeast Nigeria. Therefore, the data reduced to the equator were residualized (i.e. remove the regional) by subtracting upward continued data to 3km from the reduced to the equator data so as to obtain a magnetic response from the upper-crust of the earth consisting of the basement and the sedimentary units. The residual map was divided into eighteen overlapping blocks for the spectral analysis. The blocks were in different sizes. Hence, the investigation of Curie point depth, geothermal gradient as well as heat flow was carried out using spectral analysis. The Curie point depth obtained ranges from 3.22 to 7.16km with an average of 5.19km; the geothermal gradient of the area varies from 81.46 to 180.120C /km, with an average of 130.790C /km, while the heat flow ranges from 202.53 to 450.30 mWm-2, with an average of 326.42mWm-2. The 2D contour Curie depth map of the area shows that the deepest Curie depth is located in the northeast, northwest, and southeastern parts, while the shallowest Curie depth is observed in the central part of the area, while the geothermal gradient and heat flow, on the other hand, are highest in the central region and decrease towards the northwest. The high geothermal gradient and heat flow values in the study area are evidence that the area might be capable of geothermal energy generation.