Abstract

2D Electrical Resistivity Imaging (ERI) was carried out for pre-construction foundation investigation at the rear of the administrative complex of Federal University Oye-Ekiti, Southwestern Nigeria, to delineate the nature of the subsurface geological structures. The ERI technique was employed, using a Wenner array electrode configuration, whereby eight (8) profiles were established across the study area. 2D georesistivity maps were generated to display the resistivity distribution across the various depths of investigation. The RES2DINV results show three (3) subsurface layers with resistivities of 210 Ωm, 420 Ωm and 600 Ωm at depths of 2 m, 7.8 m, and 9.9 m, respectively. The resistivity distribution splits the study area into two zones: zones of high resistivity and zones of low resistivity. Zones of low resistivity suspected in the northwest section of the study area are depicted on the georesistivity maps, while zones of high resistivity (> 250 Ωm) are depicted in the south and northeastern sections. Zones of low resistivity are inimical to engineering structures. Geological structures such as fractures, faults, and shear zones were delineated in the study area, which could affect structures constructed on them. The 2D images and the georesistivity maps gave continuous and precise information about the subsurface in different representative geological situations.