Geophysical Characterization and Resource Evaluation of the Kaolin Clay Deposit in Ire-Ekiti, Southwestern Nigeria

Kaolin clay has long served as a vital raw material for ceramics, refractories, and construction products due to its plasticity, heat resistance, and abundance. Despite Nigeria’s rich clay resources, the country continues to rely heavily on imports of refractory-grade materials. This study employed the Vertical Electrical Sounding (VES) technique to characterise and assess the economic potential of clay deposits in Ire-Ekiti, Southwestern Nigeria. Eighteen (18) VES stations were established within an area of about 200 m² using the Schlumberger array configuration with current electrode spacing (AB/2) ranging from 1 to 100 m. Apparent resistivity data were acquired using a SYSCAL Junior resistivity meter and processed with IPI2Win and RESIST software to generate one-dimensional resistivity–depth models. The inverted results, correlated with lithologic logs and field observations, delineated three major subsurface units: a thin resistive overburden, a conductive clay-bearing horizon (18–100 Ω-m), and a highly resistive basement or sandy formation. The clay layer exhibited variable thickness, ranging from 10 m to 14 m across the area, with the thickest and most laterally continuous zones identified around VES 4, 5, 6, 7, 10, and 17. These “sweet zones” represent the most promising targets for economic extraction. The deposit’s volume, overburden characteristics, and accessibility indicate favourable conditions for industrial exploitation. Comparative assessment with similar Nigerian clay deposits suggests that the Ire-Ekiti kaolin clay is suitable for refractory and ceramic applications.