Integrated Geophysical Study of Geothermal and Mineralization Potential for Energy and Strategic Resources in the Lower Benue Trough, Nigeria

Abstract

This study investigates the geothermal and mineral resource potential of the Lower Benue Trough (LBT), Nigeria, using high-resolution aeromagnetic and radiometric data – an integrated geophysical approach. The study area spans ~27,225 km² between latitudes 6.0°–7.5° N and longitudes 7.5°–9.0° E, covering Ankpa, Otukpo, Gboko, Igumale, Ejekwe, Ogoja, Nkalagu, Abakaliki, and Basha. Few studies have jointly evaluated geothermal and mineralization prospects in the LBT using such integration, making this work novel in bridging that gap. Spectral analysis of aeromagnetic anomalies was used to estimate Curie Point Depth (CPD), geothermal gradient (GTG), and heat flow (HF), while radiometric data validated crustal heat production and delineated mineralization zones. Results show CPD values from 7.923–14.502 km, with shallower depths concentrated in Nkalagu and Otukpo, indicating elevated subsurface temperatures. These correspond to GTG > 70 °C/km and HF > 170 mW/m². Radiometric analysis reveals significant Uranium (eU), Thorium (eTh), and Potassium (K) anomalies, supporting high radiogenic heat production and highlighting uranium–thorium mineralization potential at Otukpo, Igumale, and Nkalagu, and REE prospects at Ejekwe and Abakaliki. The findings indicate strong potential for renewable geothermal energy and critical mineral exploration, directly supporting Nigeria’s energy transition and strategic mineral policies.