Geophysical Exploration of Gold Mineralization Zones using Induced Polarization and Electrical Resistivity Imaging Methods at Itagunmodi Area of Ilesha, Osun State, Southwest Nigeria

Abstract

Gold is a valuable and economically solid mineral due to its unique physical and chemical properties. However, this research investigated the potential zones of gold mineralization at Itagunmodi in Atakunmosa West Local Government Area of Ilesha, Osun State, Nigeria, through the generation of subsurface 2D resistivity and induced polarization models that provide helpful information in determining the depths and lateral distances of suspected gold deposits. The time domain-induced polarization and electrical resistivity imaging (ERI) measurements were carried out along six traverses using dipole-dipole configurations with electrode separations of 5.0 m and profile lengths ranging from 128.0-315.0 m. The apparent resistivity and chargeability data were used to generate 2D subsurface models using RES2DINV software to accurately and effectively interpret the location of gold mineralization potential zones. The results from the 2D ERI and chargeability models along traverses 1 and 2 revealed low resistivity zones ranging from 16.3-669.0 Ωm corresponding to high chargeability zones ranging from 288 to 444 msec on the 2D chargeability section, which were identified at lateral distances of 82.5-102.5, 167.0-187.5, 164.0-260, 95.0-110.0, and 55.0-75.0 m from approximated depths 9.94-26.20, 6.76-36.98, 11.0-23.0, and 6.0-12.0 m beneath the subsurface. These anomalous zones along these traverses weresuspected to harbour minerals such as goldsince they can also be attributed to quartz veins and fractures that may likely be filled with conductive materials like gold and associated base metals. This research has revealed the efficacy of electrical resistivity and induced polarization methods in delineating the suspected regions of gold mineralization.