Isaac O. Agbane1*,
Ogbadu R. Omeje2, Dayo J. Olutokun3 and Esther A. Yahaya3
1Department of Geology, Federal University
Lokoja, Nigeria
2Department of Geology, Kogi State University,
Anyigba, Nigeria
3Department of Physics, Kogi State University,
Anyigba, Nigeria
*Email:agbaneisaac@gmail.com
ABSTRACT
Geophysical investigation involving the use of vertical electrical
sounding (VES) on grid-A part of Felele
campus, Federal University Lokoja, Nigeria with
objectives to delineating depth
to fresh basement, fractured zones in the study area for potential groundwater
exploration within the crystalline basement rocks. The area is underlain by the
Crystalline Basement rocks composed of granite gneiss, quartzite and intrusions. PASI Terrameter was used and the symmetrical
Schlumberger configuration adopted. A total of four (4) Vertical Electrical
Sounding (VES) stations were established. Preliminary input data from the field
were inputed into the WINRESIST software to generate real resistivities and
depths to geoelectric layers. Three (3) geoelectric layers were interpreted,
the first layer is the top soil made up of resistivity values ranging from 141
Ωm – 486.1 Ωm and depth to weathered basement of 1.2-2.5m. It is inferred that
this layer does not consist of the same material across the entire length of
the profile. The second layer is made up of resistivity values ranging from
37.9Ωm to 85.6Ωm and depth to fresh basement of 11.2 – 16.1m. Its inferred to
composed mostly of fractured and unconsolidated rocks, loose gravel, sandy soil
and clayey. The resistivity value within this layer indicates that is it good
for groundwater exploration and the third layer has the highest resistivity
values ranging from 821.2 Ωm – 2695Ωm with an infinite depth. It’s entirely
composed of fresh basement rock which is possibly of the gneissic suite.
Keywords: Basement rocks, Fractures, Geoelctric layers, ground water, lokoja, schlumberger