Geophysical Prospecting of Parts of Isara-Remo, Ogun State, southwestern Nigeria Using 2D Electrical Resistivity Tomography

Abstract Geophysical survey using 2D Electrical Resistivity Tomography was conducted at Isara-Remo to delineate the sedimentary/basement contact as well as to prospect for the groundwater resources. Ten profiles were investigated using the Dipole-dipole array configuration and the resistivity data were processed and inverted using AGI Earth Imager software. The models obtained revealed the lithological composition of the area characterized generally by topsoil, sand, laterite, saturated sandy clay, dry sandy clay, dry clay, saturated clay, sandy clay, clayey sand, sandstones, coarse sand, shale, quartzite rock and basement rock. The models of the studied areas revealed resistivity ranges of 20.4 Ωm − 1832 Ωm; 11.6 Ωm − 327 Ωm; 6.4 Ωm − 2954 Ωm; 1.9 Ωm − 2767 Ωm; 25.7 Ωm − 1607 Ωm; 51.6 Ωm − 929 Ωm; 35.7 Ωm − 2659 Ωm; 42.5 Ωm − 1562 Ωm; 49.4 Ωm − 6113 Ωm; and 82 Ωm − 6783 Ωm for profile 01, 02, 03, 04, 05, 06, 07, 08, 09 and 10 respectively with corresponding depths of investigation at 174m, 78m, 197m, 174m, 105m, 174m, 197m, 105m, 99m and 99m. The study revealed the hydrogeological characterization and aquifer configuration of Isara, Profile 02 in ward 1 had the best groundwater potential due to its resistivity value in comparison to Profile 10 in ward 4 with low water-bearing aquifer. The qualitative information and to an extent, quantitative information on the groundwater potential in the study area have been provided and the sedimentary region delineated from the basement zones.