Arekumo Thank God, Lawrence O. Oghale
Abstract: The electrical properties of laterites was a useful tool for electrical resistivity investigations to evaluate depth and area extent of laterite top soil in Okada South-South, Nigeria. On the field electrical resistivity tomography survey was conducted along four profile using Schlumberger Wenner configuration. Acquired resistivity data were interpreted based on least square method, the resultant apparent resistivity sections were interpreted with constrain from known lithostratigraphy of the area to infer the true resistivity variation of the different litho units. The litho log from a section of a road cut outcrop on which line 1 electrical survey was done, serves as a reference for correlation between apparent resistive values and actual lithology. A tie of laterite to apparent resistivity for the study area shows a resistivity values of 600 -1000 m are laterites, 300 600 m lateritic soil with varying degree of laterization, while 100 m and bellow are clay related, these references agrees with standard references for these lithologies. The electrical resistivity tomography method was effective in delineating clay units from lateritic areas. In terms of exploration, Line 1 and 2 showed extensive concentration of laterite which toward line 2 and 3 decreased with increased patch occurrence of clays.
Keywords: Laterite, Electrical Resistivity Tomography, Okada