Integrated geophysical evaluation of potential gold mineralisation within Nigerian Yashi Sheet 56 (1:100, 000)

This research aims to identify prospective gold mineralisation zones in northern Nigeria, specifically within the Nigerian Yashi Sheet 56 (1:100,000), where artisanal mining activities are increasingly prevalent. The study integrates hydrothermal alteration analysis and structural mapping using high-resolution airborne gamma-ray spectrometry and magnetic datasets. Advanced enhancement techniques, including K/eTh ratio mapping, ternary imaging, and radioelemental distribution, were employed to assess hydrothermal alterations and improve interpretative accuracy. Structural delineation of mineralized zones was achieved through analytic signal processing and Center for Exploration Targeting (CET) Grid analysis. Results indicate that high K/eTh ratio values (0.097–0.118 %/ppm) correlate strongly with hydrothermal alteration zones and known mining sites. The highest amplitude peaks (0.058–0.140 nT/m) and high lineament density zones are identified as potential mineralisation targets. The predominant structural trends are E-W, ENE-WSW, and NE-SW, with mineralisation zones aligning more closely with the NE-SW trend. However, two of the six documented mining sites were not captured by the analytic signal and CET Grid analysis, likely due to intense potassic hydrothermal alteration, as suggested by the K/eTh ratio. A strong correlation among the datasets confirms the effectiveness of this integrated approach in delineating potential gold mineralisation zones, particularly in the southeastern part of the study area, where mining activities are concentrated. Areas characterized by high K/eTh ratios, elevated magnetic amplitudes, and dense lineament distributions are considered prime exploration targets. However, more priority is given to high K/eTh ratio due to the nature of mineralisation in the area. The findings boost the gold exploration strategy.