Determination of thermal structure of the crust beneath the Gongola Basin, Upper Benue Trough, Nigeria

Abstract

Geothermal energy resources have been established globally to be among the sustainable and environmentally harmless means of energy generation. The data for this study came from the Earth Magnetic Anomaly Grid 2 version 3 (EMAG2V3). It was acquired at a flying elevation of 4 km above the ellipsoid and has a resolution of 2-arc minutes (3.66 km). This research aim to study the thermal structure of the crust beneath the Gongola Basin so as to determine the heat flow, geothermal gradient and the Curie point depth. In this study, the creation of an air satellite magnetic map of the Gongola Basin is accomplished through the use of a fractal magnetization approach. However, Curie point depth (commonly known as bottom most of magnetic sources depth) measure the distance between two points in space, depth to bottom magnetic source (DBMS). Geothermal characteristics of the area was evaluated using Oasis Montaj. So the earth magnetic field is utilized to determine the depth of anomalous sources that ranges from few meters to tens of kilometers. The top depth ranges from 3.4465km to 10.942km, the centroid depth ranges from 14.045km to 31.338km, the geothermal gradient ranges from 10.2566Oc/km to 23.4445 Oc/km and the heat flow ranges from 25.6415mW/m2 to 58.84 mW/m2. The study identify a point (11°63E, 10°12N) with optimal values (26.44OC/km, 66.11mW/m2) at a distance 21.9km which is above the typical optimal values obtained in stable continental craton as obtainable in African plate.