2D electrical resistivity method Subsurface lithology Geophysical survey University of Benin Benin City Wenner-Alpha configuration Vertical Electrical Sounding

This study aimed to investigate subsurface lithological structures at the University of Benin, Benin City, Nigeria, using the 2D electrical resistivity method. Field data was acquired using the Wenner-Alpha configuration, and processed using RES2DINV software to generate 2D resistivity models. The results revealed a multi-layered subsurface structure, typically consisting of an upper layer of alluvium (soil) with varying amounts of clay, underlain by layers of shale and sandstone. The resistivity values ranged from 131 Ωm to 6239 Ωm. Vertical Electrical Sounding (VES) data provided further insights, identifying five distinct layers and providing more accurate depth and thickness information compared to the Wenner array. The study demonstrates the effectiveness of the 2D electrical resistivity method in characterizing subsurface structures and provides valuable information for construction planning and geological assessments in the study area.