Abdulrahaman Idris Augie

Federal University Birnin Kebbi, Nigeria

Title: Evaluation of Gold mineralisation Potential using Airborne Magnetic and Geoelectrical Methods over Middle part of Zuru Schist Belts, NW Nigeria.

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Biography

Abstract

This study delineated the potential zones for gold mineralisation using aeromagnetic, 2D electrical resistivity tomography (ERT), and induced polarisation (IP) techniques. Half-degree airborne magnetic data sheets of 96_Shanga and 119_Yelwa that covered the study area were obtained from the Nigerian Geological Survey Agency (NGSA). The tilt derivative (TD), analytic signal (AS), and centre for exploration targeting (CET) methods developed in Oasis Montaj Geosoft were applied to these datasets during the data processing and analysis. The TD, AS, and CET results revealed areas of high amplitude magnetic anomalies (zone H) and major magnetic structures (lineaments), which are associated with granite gneiss, quartzite, gneiss, partially decomposed granite, migmatitic augen gneiss, and medium to coarse-grained biotite in comparison to the geological setting of the area. Major zones of structures and high magnetic anomalies were found in the eastern regions of the Ngaski-Yauri boundaries (Mararraba), Shanga (Sabon Gari), Agwara, and Magama (Irana), and these have agreed with earlier magnetic studies conducted in the region. These sites could potentially be favourable for metallic minerals, particularly gold mineralisation. However, some regions (Ngaski/Yauri boundaries and Sabon-Gari) obtained through the magnetic method for potential gold mineralisation were further investigated using 2D ERT and IP detailed techniques in a dipole-dipole configuration. The geoelectric method results along profiles 1, 2, and 3 revealed three major zones of gold mineralisation potential, denoted as G1, G3, and H1. These regions have low/high resistivity (1.5 to 460 ?m/1890 to 7873 ?m) and high chargeability (? 20 msec), which could be interpreted as potential for metallic mineral exploration, especially for gold. The zones are in northern Mararraba, Bajida, and Gonan Goli in Kebbi state. The results of integrated geophysical techniques yielded a database of precise coordinates, lateral lengths, and thickness/depths for potential gold mineralisation zones. This database could help with the exploration of gold minerals in the region.