Aquifer potentials and their relevance in subsurface groundwater protection were assessed at Abeokuta North Local Government Area, South-West Nigeria. Fifteen (15) Vertical Electrical Sounding (VES) were conducted using Schlumberger configuration with the maximum electrode spacing (AB/2) of 100m at each point using Allied Omhega Resistivity meter. The data were interpreted using partial curve matching techniques and computer iteration program using WINRESIST software. Delineated aquifer parameter values were used for evaluating its protective nature to contaminant seepages. The range of reflection coefficient was found within 0.0328 (VESAN3) and 1.5841 (VESAN1). Consequently, protective capacity was found to vary between 0.0021 (VESAN1) and 0.4309 (VESAN2). In terms of yields, (20%) possessed high groundwater potentials, 12 (80%) had low groundwater potentials while none exhibited moderate or medium groundwater potentials. Also, the study area shows a very poor, and moderate protective capacity rating. Four (4) VES stations exhibited very poor protective capacity (26%), ten (10) VES stations show poor protective capacity (67%) and only one (1) VES station depicted a moderate protective capacity rating. Since the longitudinal conductance revealed the impermeability of the confining layers which is generally ? 1.0 Siemens; values ?1.0 Siemens indicates zones in which the confined aquifer is protected by the overlying formation materials; these suggest that the groundwater quality may have been compromised necessitating the urgent need for groundwater sampling and analysis.

Keywords: : Schlumberger, Curve-matching, Reflection-coefficient, Resistivity, Longitudinal- conductance, Vulnerability, Impermeability