Geophysical Mapping of Aquifer Properties in a Basement Complex Region, Southwestern Nigeria

Student: samuel olamillekan fatayo (Thesis, 2025)
Department of Geophysics
Federal University Oye-Ekiti, Ekiti State


Abstract

This project presents a comprehensive geophysical analysis of a subsurface region using geoelectric data to generate values of transverse resistance and longitudinal conductance. The transverse resistance map reveals significant variations in resistivity, with values ranging from below 0 ohm-m to over 7000 ohm-m, indicating diverse subsurface properties, including fluid saturation and varying geological units. The longitudinal conductance map further highlights regions of high conductivity, exceeding 0.09 mhos, suggesting zones of fluid saturation or clay- rich formations, contrasted by lower conductance areas that may represent more resistive materials. The aquifer thickness map demonstrates substantial variability, with thickness values ranging from less than 1 meter to over 14.5 meters, identifying critical zones for potential groundwater extraction. The aquifer resistivity map corroborates these findings by showing resistivity values from below 100 ohm-m to above 700 ohm-m, reflecting the heterogeneity of the aquifer materials and their varying water content. Together, these geophysical findings provide essential insights into the subsurface characteristics, offering valuable information for hydrogeological assessments, groundwater management, and potential resource exploration.

Keywords
geophysical mapping aquifer properties basement complex Southwestern Nigeria groundwater geophysical techniques geological terrain