RESISTIVITY TECHNIQUES FOR GROUNDWATER EXPLORATION IN PARTS OF BASEMENT COMPLEX OFSOUTHWESTERN NIGERIA
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Date
2023
Journal Title
Journal ISSN
Volume Title
Publisher
Faculty of Physical Sciences, Nnamdi Azikiwe University, Awka, Anambra State, Nigeria.
Abstract
Quality water for use has been abysmally difficult to come by in the Oye Ekiti metropolis. Thus, an aggressive
exploration effort toward providing clean water is essential in the area. The study is within the coordinates of
longitudes 5
0 41' 40 "E - 5
043' 20"E,and latitudes 70 31'50"N -7
ᵒ 62' 50"N. Thus 9 Horizontal Profiling (HP)
traverses, 9 Spontaneous Potentials (SP) traverses, and 31 Vertical Electrical Sounding (VES) points were
employed to assess the groundwater potential of the area. The SP identified zonesthat show a peak of varying
polarity indicating streaming potential which is evidence of groundwater movement.The movement is majorly
directed in the East-to-west axis, indicating the major groundwater flow directions in the area.HP inversions
and 2D models from most of the traverses indicate aquiferous layers with average resistivity and depth range
of 10.5 – 93.5 Ωm and 50 – 90 m in the area. The geologic sections delineated five subsurface geologic layers;
this includes the topsoil, laterites, sandy clay, weathered basement, and fresh basement. The resistivity range
of the fresh basement is 535 – 6176 Ωm. The weathered basement is generally thin and constitutes the main
aquifer unit within the area. The resistivity low of the weathered basement could indicate enhanced
permeability due to significantly fractured density and the tendency for moderate groundwater potential and
yield through the groundwater potential map. The area could therefore be said to portray a moderate
groundwater potential.
Description
Keywords
Hydro-geophysical, Resistivity, Delineation, Fracture and Aquifer