Evaluation of Clay Mineral Deposits in Ohiya, Southeast Nigeria Using the Self Potential Method and Lithologs

A self potential survey was carried out on the study area. Four prospects were considered. The prospects investigated had a total area of 2.34 km2. 18 profiles were obtained from the prospects alongside three other random considered profiles. A total of 315 SP measurements were obtained using the direct potential method with a 10 m increase in the electrode spacing along each of the profiles. Obtained data show a potential range of -2 mV to -600 mV and 1 mv to 251 mV. On analysis, SP spectral signatures and the tomography map reveals that there were also non-conductive materials like silt, sandstone, sand, etc. which constitutes impurities and the overburden. The Iso-Potential contour map of the study area also reveals Nkwoebo, Egbeada and Umuoram as areas of likely kaolin abundance. Litho-logs of excavated sites were obtained to give us a quantitative clue of the mineral in the investigated prospects. It was observed that the overburden thickness is about 1.22 m, the thickness of kaolin deposit to be above 12.2 m and the average bulk reserve is about 74,360,000 metric tons.