Delineation of potential gold mineralization zones in Phitshane Molopo area Southeast Botswana using induced polarization and resistivity measurements

Abstract

An integrated geophysical approach (using induced polarization together with resistivity) geophysical techniques was applied in the research area (Phitshane Molopo area, Botswana) in search for potential gold mineralization from the interpreted data to delineate potential sites for mineralization. Reports on historic exploration suggest that gold mineralization is associated with quartz ± carbonate veins that cut across the banded iron formations. The 2D IP/ERI measurements were acquired along ten 300 m long profiles trending northeast southwest, with 15 m line separation and 7.5 m electrode spacing. The data were then inverted using the standard Gauss-Newton optimization method to produce 2D and 3D models. Based on a combination of IP and resistivity results, two anomalous zones are observed increasing in strength from line 1 to line 10. Possible mineralization is observed to be at shallow depths as evident from the 2D models and 3D horizontal sections. Since all of the high chargeability zones shown on the chargeability models correspond to parts which are highly resistive, then these zones exhibiting distinct anomalies can be mapped out as possible areas of disseminated sulphide mineralization hosted within quartz veins cross-cutting banded iron formations. The integrated use of IP and ERI methods was successful in delineating zones that are likely to be hosting disseminated sulphides and/or potentially gold-rich zones in the Phitshane Molopo area, Kraaipan Greenstone Belt.