Abstract

Twenty Five Schlumberger depth sounding data from Oke-Ila and environments, Southwestern Nigeria was interpreted to delineate the aquifers. The geoelectric parameters of the uppermost layer across the area were used to assess the vulnerability of the underlying aquifers to the surface and near-surface contaminants. The aquifer in the area is located mostly within the weathered layer above the basement rock and occurs at a shallow depth ranging from 3.9 to 15.7 m, where depths less than 8 m constitute 52% of the study area. The average depth to the aquifer is 8.6 m. The protective capacity of the overburden showed that 60% of the study area has poor protective capacity, 12% weak protective capacity and 28% moderate protective capacity. This suggests that aquifers within the weathered basement rock are prone to surface and near-surface contaminants.

Key words: Intrinsic, aquifer, vulnerability, saprolite.