Journal de géologie et géophysique
Libre accès

Abstrait

Application of Electrical Resistivity in Delineating Depth of Auriferous Veins in Parts of Minna, North-Central Nigeria: Implication for Gold Exploration

Wallace Ogor*

Gold for its high resistance to chemical reaction, high conductivity and ductility, and its rarity has been one of the most sought-after commodities for at least 7000 years and geophysical techniques (gravity, magnetics and electrical methods) have been widely used to get subsurface information of the Earth, without engaging in invasive digging. The geophysical evaluation of gold mineralization potential in parts of Minna has been carried out using three (3) principal geophysical techniques; Vertical Electrical Sounding (VES), Horizontal Resistivity Profiling (HRP), and Electrical Resistivity Tomography (ERT), with Schlumberger, Wenner and dipole-dipole electrode configuration respectively. These result of the analysis of the data obtained revealed a resistivity variation ranging from 20-75 Ωm in different parts of the study area. Also, it indicates a mineralized body that is discontinuous and irregular. The mineralized body is inferred to be gold as a result of the artisanal mining activities ongoing in the study area. The three (3) approaches classify the gold as shallow deposits as they exist between 0.8 m to less than 5 m deep in most cases because of this, they are easily eroded along the surrounding stream and river, and hence, the investigated area could be categorized as alluvia deposits. The resistivity data have been able to delineate a NE-SW trending anomalous zones that is parallel to the regional foliations which is consistent with the auriferous quartz vein exposed by the artisanal gold workings.