Self Potential Anomalies and their Minerological Implications, A Case Study of Some Parts of Southern Umuahia, Abia State, Nigeria

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. The SP method involves
the measurement of the differences in natural ground potential between any two points on the ground
surface which ranges from less than a millivolt to over ten volts. This method has some mineralogical
implications in that it has been used in massive base metal exploration to detect the presence of
massive ore bodies. It has also been extended to groundwater and geothermal investigations,
environmental and engineering applications to; map seepage flow associated with dams, in geological
mapping and in delineation of shear zones and near-surface faults. This work seeks to x-ray the
principles of SP survey with evidence from the survey carried out in some parts of Southern Umuahia,
Abia State, Nigeria. Seven locations where SP survey was carried out showed a negative anomaly of
-2mV to -600mV and a positive anomaly of 5mV to 277mV 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.