Integrated 2D Geoelectric Prospecting for Gold Mineralisation Potential Within Southern Part of Kebbi, NW Nigeria

Abstract

This is a detailed geophysical research into the anomalous zones identified by pre- vious aeromagnetic studies in the area. Integrated 2D geoelectric prospecting methods involving ERT, IP and SP techniques were used to delineate subsurface structure suitable for gold minerali- zation potential in parts of the Yauri, Shanga, and Magama areas of the states of Kebbi and Niger in the northwest Nigeria. The ERT, IP and SP measurements were carried out with a dipole-dipole configuration and the SuperSting resistivity meter. The research results revealed regions with low/high resistivity, high chargeability, and high SP values, which were identified as mineral po- tential zones. The ERT technique has helped to delineate regions with low resistivity anomalous which correspond to oxidized rocks associated with granite/quartzite veins. High resistivity range could exist over dyke structures associated with partially decomposed granite and quartzite, as in- dicated by the geological setting and borehole log of the area. The IP technique revealed a high chargeability (≥ 20 milliseconds) in the study area, possibly due to the accumulation of metallic minerals in host rocks, such as gold. The SP technique has also helped to identify regions with high SP anomalies (≥20 mV), which are characterized by vein-bearing ore minerals. The integration of ERT, IP, and SP results revealed oxidized rock zones, dyke subsurface structures of decomposed quartzite, granite, gneiss, and ore mineral veins. These zones are located in the northwest Mararra- ba, the southwest Jinsani, and the southern Sabon Gari in Niger and Kebbi states. The areas could be considered a potential pathway for gold exploration and exploitation.