Integrated magnetic and radiometric data analysis for mineral exploration and environmental studies in the neoproterozoic terrain of Southern Kebbi State, North-western Nigeria

Abstract

This study aimed to establish the rich mineral potential of Southern Kebbi State's Neoproterozoic terrain and to highlight radiation hazards associated with uncontrolled mining activities in mineralised areas. Magneto-radiometric correlation analyses were used to delineate mineralised structural frameworks. The derivative filters, rose diagram, and Centre for Exploration Targeting (CET) analyses revealed near-surface structural networks trending mainly NE–SW. Analytic signal and 3D Euler deconvolution analyses helped classify the mineralised structures as shallow- or deep-seated. The estimated depth to mineralised structures ranges from 85.00 to 1282.30 m, with densely structured regions of interest hosting shallow structures within 85.00–203.30 m. The high occurrence of radioelements resulted in elevated activity concentrations, peaking at (1095.50 Bq/kg, 128.30 Bq/kg, and 88.75 Bq/kg), compared to lower crustal averages of (420.0 Bq/kg, 45.0 Bq/kg, and 33.0 Bq/kg) for AK, ATh, and AU, respectively. The annual dose rate ranged from 28.73 to 150.73 nGyh−1, surpassing the tolerable rate of 60.0 nGyh−1. AEDEin and AEDEout were estimated at 0.41– 0.73 mSvy−1 and 0.035–0.185 mSvy−1 respectively, against lower thresholds of 0.41 and 0.07 mSvy−1. Gamma, alpha, and radiological hazard indices remained within the safety limit of 1.0; however, reproductive health (AGDE) and cancer (ELCR) indicators, measured as 198.25–1042.16 μSvy−1 and (0.49–2.58) × 10−3, exceeded limits of 300 μSvy−1 and 0.29 × 10−3, respectively. Locations of mineral interest with high radiological parameters include Shanga, Beri, Bajida, Dafore, Rijau, Mazama, Agwara, Yelwa, Bin-Yauri, Maburo, Gulbin-Bako, Tungan-Numa, Makawa, Anaba, and Zoma. While the high radiological parameter values suggest significant potential health risks, expanding this study to include an assessment of the local population's health status was beyond the scope of the current research.