Delineation of potential zones of lead-zinc mineralization in Uburu Ohaozara L.G.A South Eastern Nigeria, using electrical resistivity tomography and induced polarization methods

Abstract

An integrated geoelectrical study combining electrical resistivity tomography (ERT) and induced polarization (IP) have been used to delineate potential zones of Lead-Zinc mineralization in Umuobuna, Uburu, Ohaozara local government area, southeastern Nigeria. The wenner array configuration was used to acquire resistivity and induced polarization data sets along three traverses of approximate length of 1 km each and spacing of 5 to 25 m, using ABEM Terrameter SAS 1000. The profiles were inverted using RES2DINV software for 2D imaging to delineate possible zones of Pb-Zn mineralization and the geological structures at selected locations in the study area. The ERT surveys were carried out along the IP lines for comparison of anomalies across the profiles. The potential zones of Pb-Zn mineralization display contrasting values of resistivity and chargeability along the traverses. Resistivity values ranging from 7.53 to 7525 Ωm and corresponding chargeability values of between -15.6 and 354 ms, respectively were encountered at some intervals along the traverses. These zones occur at width range 19.5 to 74.5 m and depths of between 0.9 and 15.5 m. Having a low to moderate resistivity and a corresponding high chargeability values at similar width range may be suggestive of Pb-Zn mineralization and test drilling is needed at the anomalous sites for confirmation.