Integrated Geophysical Appraisal of Groundwater Potential in a Crystalline Basement Terrain Using Vertical Electrical Sounding: A Case Study from Chikun and Environs, North-Central Nigeria

Abstract

This study conducts a detailed geophysical assessment of groundwater potential in 
the crystalline basement terrain of Chikun and its environs in North-Central Nigeria, 
employing the Vertical Electrical Sounding (VES) technique. The region is geologically 
characterized by porphyritic granite, granitic gneiss, and mica schist, which exhibit 
varying degrees of weathering and fracturing—key factors influencing groundwater 
accumulation and movement. A total of fifteen VES stations were surveyed within 
the Kakuri Sheet 144 NW, revealing four to six distinct geo-electric layers. These 
layers include topsoil, sandy clay, consolidated sand, highly weathered basement, 
slightly weathered basement, and fresh basement rock. Resistivity values recorded 
across the area ranged from 195.3 to 604.4 Ωm. Zones with lower resistivity were 
interpreted as water-saturated layers, indicative of potential aquifer units. Notably, 
VES points 1, 2, 5, 8, 9, 13, and 15 displayed favorable geoelectrical characteristics 
for groundwater development, making them suitable candidates for borehole drilling. 
The fractured and weathered basement units constitute the primary aquifer zones, 
providing a dependable source of groundwater within this otherwise low-permeability 
hard rock environment. The findings affirm the effectiveness of VES as a non
invasive, cost-efficient method for delineating subsurface hydrogeological 
structures and identifying viable groundwater zones. This integrated geophysical 
approach not only enhances groundwater exploration and development in the study 
area but also offers a practical and replicable model for similar crystalline basement 
terrains across sub-Saharan Africa—especially in regions facing seasonal water 
scarcity and increasing demand for sustainable water supply.