Analysis of Geophysical Exploration Techniques for Detecting Buried Mineral Deposits in the Chad Basin, North East Nigeria

The Chad Basin in North East Nigeria contains sedimentary sequences with hydrocarbon and solid mineral prospectivity, yet the identification of buried economic mineral deposits remains challenging due to thick Quaternary cover. This study analyses the application and comparative effectiveness of ground geophysical exploration techniques for detecting buried mineral targets in the Nigerian Chad Basin. A multi-method geophysical survey comprising ground magnetic, induced polarisation, and controlled-source audio-frequency magnetotellurics was conducted over a 120-square-kilometre study area in Borno and Yobe states. Data processing and interpretation were performed using industry-standard software, and anomalies were classified by their geophysical signature type. Three priority drill targets were identified from interpretation, and two were verified by shallow rotary drilling. Results demonstrate that combined magnetic and induced polarisation surveying provides the most cost-effective detection approach for sulphide-associated mineralisation targets beneath the Quaternary cover. Magnetic susceptibility contrast between basement lithologies and potential ore bodies produces detectable anomalies at depths up to 120 metres. Electromagnetic methods effectively identify conductive sulphide bodies but require longer data acquisition times per unit area. The study establishes a geophysical exploration protocol for the Nigerian Chad Basin and recommends the integration of airborne electromagnetic data from the NGSA national survey programme for regional target generation. Keywords: geophysical exploration, Chad Basin, mineral deposits, North East Nigeria, induced polarisation.