Investigation of Graphite and Sulphide Minerals in Some Parts of Southern Umuahia Using Self Potential Anomalies

Self Potential, an electrical geophysical method is chiefly used in mineral prospecting. Vertical and lateral variations in the conductivity of earth materials produce variations in the potential distribution as measured on the surface thereby giving information of the sub-surface. A self-potential survey was carried out in the study area. Seven locations were considered. The profiles investigated had a total area of 2.34 km2. A total of 315 self potential measurements were taken using the direct potential method with a 10m increase in the electrode spacing along each of the profiles. Obtained data show a negative anomaly of -2 mV to -600 mV and a positive anomaly of 5 mV to 277 mV distributed within the study area. It was observed that the potential anomalies are due to some conductive minerals like graphite and sulphide ore bodies. The Iso-potential contour map of the study area was made with an interval of 50mV which reveals the mineralogical trend of sulphide and graphite ore bodies. It was deduced that Nkwoebo, Umuoram and Egbeada regions of the study area would most likely have a graphite ore body while Umuchime, Amachara and Umuokwom will most likely have a sulphide ore body.