Delineation of Potential Gold Mineralization Zones in the Kushaka Schist Belt, Northcentral Nigeria, Using Geochemical, Ground Magnetic, Induced Polarization, and Electrical Resistivity Methods
摘要
This study integrated geophysical methods (ground magnetics, electrical resistivity, and induced polarization measurements) in conjunction with fire assay and inductively coupled plasma-atomic emission spectrometry techniques to delineate orogenic gold mineralization potential zones in the Kushaka greenschist belt. Different edge detection filters and a 3D Euler deconvolution technique were applied to magnetic data to delineate geologic structures that control orogenic gold mineralization in the study area. VOXI Earth Modeling™ software was applied to induced polarization and electrical resistivity data to generate gold mineralized targets in the study area. Based on the geochemical findings in this study, orogenic gold mineralization in the belt is associated with galena, sphalerite, monazite, bastnaesite, and manganese oxide minerals and has a metamorphic origin. The total magnetic field results indicate that NE-SW and NW–SE trending structures are primarily associated with gold assay hotspots, indicating that orogenic gold mineralization in this belt is connected to Pan-African orogenic events. Fractured zones with disseminated gold-sulfide deposits and hydrothermal alteration halos exhibit low resistivity and high chargeability signatures. However, the occurrence of disseminated gold-sulfide deposits that infilled quartz veins and fractured zones in the intensely silicified metasedimentary rocks exhibit high chargeability and high resistivity signatures. The produced gold mineralized targeting model correlates well with geologic structures, metasedimentary rocks, and gold hotspots, indicating that lithologies and geologic structures preferentially control orogenic gold mineralization in the belt. Hence, the information gathered in this study would assist miners and academia in determining the drill-hole locations for future gold exploration programs in the area.