Correlating geophysical anomalies with subsurface lithology: Insights into gold mineralisation

Abstract

Accurate delineation of gold mineralization in deeply weathered tropical terrains requires the integration of indirect geophysical data with direct subsurface observations. Electrical resistivity imaging (ERI) and induced polarization (IP) are widely used in mineral exploration; however, interpretation is often limited by non-uniqueness without borehole validation. This study evaluates the reliability of combined resistivity and induced polarization (Res-IP) methods for identifying sulphide-associated gold mineralization in the Central Belt of Peninsular Malaysia (CBPM) through correlation with borehole lithological data. The investigation was conducted in Jeli, Kelantan, a known gold-bearing region, using two intersecting 400 meters survey lines (SL-1 and SL-2) acquired with 61 electrodes at 5 to 10 meters Schlumberger spacing to generate two-dimensional (2D) Res-IP models. Boreholes Y (BH-Y) and Z (BH-Z) were drilled along SL-1 to validate geophysical anomalies, with detailed geological logging performed at 1.5 meters intervals to document lithology, alteration, quartz veining, and sulphide occurrence. The results reveal a consistent geophysical signature characterized by low resistivity (<100 Ωm) and high chargeability (>100 msec), indicative of disseminated to vein-hosted sulphides. These signatures correlate directly with quartz–sulphide vein intersections at depths of 70 to 72 meters in BH-Z and 102 to 102.6 meters in BH-Y, confirming subsurface structural and mineralogical continuity. This study establishes calibrated resistivity–chargeability thresholds for sulphide-bearing formations in tropical Malaysian geology, improving ERI interpretive confidence in highly weathered environments. The findings highlight the value of integrated geophysical and geological approaches for enhancing drill targeting and reducing exploration uncertainty in gold-prospective regions of Malaysia.