Integrated geophysical data for 2D/3D gold target delineation in the Bidou area, Nyong Group, Cameroon

Abstract

The Bidou area is located within the polymetallic province of the Nyong Group (southwestern Cameroon), which is structurally controlled by N–S to NNE–SSW-trending regional structures. This study aims to delineate the 2D/3D geometry of potential primary gold mineralization targets by integrating magnetic, radiometric, and electrical (IP/resistivity) geophysical data. Interpretation of the vertical derivative and analytical signal of the reduced-to-pole magnetic field highlights a well-defined N–S to NNE–SSW magnetic anomaly corridor interpreted as a potential primary gold-bearing structure. Radiometric analysis of the K/Th ratio map reveals a thorium anomaly spatially coincident with this magnetic corridor, suggesting thorium mobilization related to hydrothermal processes. Inverted IP/resistivity sections identify very high and high chargeability domains spatially associated with low to very low resistivity zones, interpreted as altered structures, clay-rich zones, and sulfide-bearing metamorphic units potentially associated with gold mineralization. Three-dimensional correlation of the chargeability sections enabled the construction of a 3D model of the very high chargeability (VHC: 50–590 mV/V) and high chargeability (HC: 20–50 mV/V) domains, with estimated volumes of approximately 2.25 × 10⁹ m³ and 1.85 × 10¹⁰ m³, respectively. The individual VHC model further confirms the persistence of the N–S to NNE–SSW anomaly corridor at depth. These results demonstrate the effectiveness of an integrated geophysical approach for first-order gold exploration targeting in structurally complex Precambrian terrains.