Vertical Electrical Sounding as a Viable Tool for Investigating Subsurface Lithology at Auchi, Edo State of Nigeria

Abstract

Vertical electrical sounding (VES) utilizing schlumberger electrode array was used to investigate subsurface lithology in Auchi, Edo State of Nigeria. Ten (10) VES (uniformly distributed) were conducted at four(4) different stations. The need to carry out this research became inevitable in view of the fact that subsurface lithologies are of economy importance to mankind for development for example clay which is one of the subsurface lithologies if discover can solve the problem of youth resistiveness by way of mining industries that rely solely on clay. The software, IPI2WIN which utilizes computer iteration was used to plot graph of apparent resistivity versus semi current electrodes spacing. From the results, the number of subsurface layers, their corresponding resistivities and thicknesses of each layer were obtained. The result of the VES showed the existence of the following subsurface lithologies or rock types: top soil, wetsand, clay, sandstone, and sands having resistivities from 100.0 ohm-m to 32000 ohm-m, depths in the range 0.50m- 180.0m and thicknesses in the range 0.50m-75.0m. Area of probable subsurface lithological formations and their thicknesses have been identified for economical purposes, environmental purposes, engineering purposes, especially for future, mining of industries foundation operations and drilling.