ABSTRACT

The electrical resistivity imaging (ERI) method was implemented within the University of Benin (UNIBEN) area in Benin City, Edo State, to assess the deposition of clay. ERI serves as a non-invasive technique for determining clay deposit and its thickness without altering soil composition or functionality. The study employed Dipole-Dipole Wenner and Schlumberger array configurations across two survey lines, each spanning 200 meters with 10-meter electrode spacing. Data acquisition was facilitated using the ABEM Terameter Signal Averaging System (SAS) 300, with subsequent processing conducted through IX1D and Dipro software. Results revealed varying resistivity values ranging from 1 to 18000 Ωm, with an approximate inquiry depth of 50 meters for the profiles. High resistivity zones, registering around 2000 Ωm, were indicative of coarse sand presence, whereas layers exhibiting resistivity values, ranging from 50 to 70 Ωm depicting a wet sand, lower resistivity zones, ranging >50 Ωm, signified clay deposits occurring at a depth of 5m having a thickness of 41.0600 m. Furthermore, Vertical Electrical Sounding (VES) investigations probed depths of up to 60 meters, unveiling resistivity values ranging from 1 to 4,500 Ωm. This exploration delineated five lithological layers, encompassing sandy top soil, to sandy clay, clay, sandstone, and sandy clay.