Groundwater Potential Evaluation in the Crystalline Basement of Gidan Kwano Campus, Federal University of Technology, Minna, North-Central Nigeria Using Geoelectric Methods

Abstract

Gidan Kwano campus of the Federal University of Technology, Minna, is located within the basement complex terrain of North-Central Nigeria and is underlain by Pre-Cambrian basement rocks of which granites are predominant. Vertical Electrical Sounding (VES) employing the Schlumberger electrode configuration was used to provide information about the subsurface lithology and structures with the aim of evaluating its groundwater potential. A total of 48 VES was made along eight profiles with six sounding stations per profile within an area of about 10km2. A combination of VES, Horizontal Resistivity Profile and Sounding – Profiling produced a subsurface geological appraisal of the study area. Results of the interpretations of VES data were used to produce fracture map and isopach map of depth to basement which has a mean value of 35 m. Interpreted fractures coincide with the direction of stream flow suggesting a structurally controlled drainage system. VES curves reveal that the area is generally characterized by three geoelectric layers. Top soil layer thickness range from 0.2m to 7.4 m while the weathered layer thickness range from 0.3 m to 58.8 m. Out of the 48 VES made, 8 VES stations have been selected as priority locations for the development of groundwater resources. The study area has been found to have a very high potential for groundwater development. Despite all the limitations of the VES technique, it has been found to be reliable for groundwater exploration in the basement complex terrain particularly when the Schlumberger Configuration combined with geological and computer - aided interpretation for the survey data is implemented.