Delineation and Quasi-3D Modeling of Gold Mineralization Using Self-Potential (SP), Electrical Resistivity Tomography (ERT), and Induced Polarization (IP) Methods in Yassa Village, Adamawa, Cameroon: A Case Study

The Lom volcano-sedimentary formation belongs to the Adamawa-Yade (AYD) domain of the Pan-African fold belt in Cameroon. It is a geological formation presenting mineral deposits of economic potential such as gold and diamonds. The area is under small-scale and many artisanal gold mines. A geophysical study was carried out in the village Yassa, a locality situated within this geological formation, close to an artisanal mining excavation in order to define and propose a model of potential mineralized targets. The geophysical study involved the combination of electrical resistivity tomography (ERT), induced polarization (IP), and self-potential (SP) methods. The acquisition of data consisted of 15 electrical tomography lines in Schlumberger arrangement and a collection of SP data along these profiles in the absence of injected current. The anomalies of possible sulfide mineralization were found at a depth of about 10-25 m with a major NE-SW trend by applying the Euler deconvolution to the SP data. The ERT and IP data allow the production of the 2D inversion which is interpolated to obtain pseudo-models of the isosurface of potential mineralization. The correlation of geological information and the 3D isosurface pseudo-models indicates the characterization of zones with sulfides, with high chargeability values (>= 30 mV/V). A body exhibiting this high chargeability correlating with a low resistivity (<= 60 omega m) is observed south of the study area. This body linked to a sulfurized zone presents its roof at an average depth of 13 m with a lateral extension in depth and a NE-SW orientation in agreement with the overall orientation of the area's major tectonic lines. Another polarizable body, located in the near surface to the north of the study prospect over an average depth of about 10 m, correlates with high resistivity (4500 omega m), thus characterizing a probable zone of silicification.