Geo-electrical investigation of groundwater potential and subsurface structures in part of Pompo Village, Minna, North-central Nigeria

Abstract

The electrical resistivity survey (VES) method was used to carry out groundwater investigation to delineate the aquiferous units in Pompo, which is a settlement in the neighbourhood of the Gidan Kwano campus of the Federal University of Technology, Minna. Pompo lies within the Pre-Cambrian Basement Complex of Northern Nigeria, and is mostly underlain by the Migmatic-Gneiss Complex, coarse-grained biotite granite and granodiorite. The survey was carried out on a grid of 500 m x 500 m. Interpretation of the data was done using IP2win software, in which a layering model was obtained with the digitized sounding curve for each of the six profiles. The results obtained show that the area is generally underlain by three geologic sections (lateritic top soil, weathered basement and fresh basement). However, in some sections, where the basement had experienced severe weathering leading to fracturing of the basement rocks, four layer models were obtained. The weathered basement that is the aquifer system of the study area is generally characterized by low resistivity that is less than 400 m with basement depth between 20.0 m and 35.0 m found in the eastern and south-eastern zones.