Integrated Geophysical Investigation of Aquifer and Its Groundwater Potential in Camic Garden Estate, Ilorin Metropolis North-Central Basement Complex of Nigeria
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Date
2019-04-30
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Publisher
IOSR Journal of Applied Geology and Geophysics (IOSR-JAGG)
Abstract
This paper presents a geophysical study for ground water evaluation in a typical crystalline
basement complex terrain of Camic garden estate in Ilorin metropolis, North central basement complex of
Nigeria. Very Low Frequency-Electromagnetic (VLF-EM) and Ground Magnetics (GM) were used for structural
evaluation/delineation combined with Electrical Resistivity Method (ERM) using the Vertical Electrical
Sounding (VES) Technique. Eight (8) VLF-EM and GM profiles covering a distance range of 70 to 300 m were
established, VLF-EM at a measuring intervals of 10 m each, while six (6) VES were carried out based on
quantitative, semi-quantitative of the VLF-EM and GM, a correlation was also carried out between the VLF-EM
and the GM results of conductive zones and zones of low magnetic susceptibility that may be diagnostic of fault,
fracture/weathered material. The six (6) VES were carried out using Schlumberger configuration, with AB/2
varying from 1.00 m to 225.00 m, with the predominant curve being of the HA type representing three-layer earth
model i.e. the top soil, the clayey/weathered layer, and the fresh basement for most of the curves obtained, the
clayey/weathered layer constitutes the major auriferous unit in the area, and are characterised by moderately
low resistivity value which ranged between 23.00 and 200.00 Ωm while the thickness varies 13.2 to 61.0 m. The
study reveals that 83% of the study area may be of low water bearing/yield owing to the thick clayey column that
characterised the weathered layer without fractured basement. Therefore, there is a critical need for elaborate
ground water study in the entire area, to be able to site boreholes with a reasonable yield in an environment
where fractured basement/bedrock is rare to find.