Groundwater Prospecting and Lithology Description in Kreigani Town, Southern Nigeria, Using Vertical Electrical Sounding

Abstract

Electrical resistivity survey was carried out to determine the groundwater potentials and subsurface lithology in Kreigani town, Ogba/Egbema/Ndoni L.G.A of Rivers State. Vertical electrical sounding method with Schlumberger array using ABEM SAS 1000 Terrameter was employed to delineate the variation in the lithologic distribution and depths to aquiferous formations in the area. Five (5) vertical electrical sounding were carried out with a maximum spread of 300m. The VES raw data obtained from the field was improved with the use of WINRESIST computer software by converting the apparent resistivity values obtained from electrode spacing to apparent resistivity values as a function of the depth of each layer delineated. The geo-electrical data obtained from VES 1 revealed five (5) nd lithologic layers of curve type AAA with topsoil to a depth of 1.8m, 2 layer; fine sand with strata thickness of 3.2m, rd th 3 layer; medium sand with thickness of 11.4m, 4 layer; coarse sand with thickness of 29.5m, 5 layer, coarse sand to th th an infinity depth. The 4 layer is observed to be aquiferous with resistivity of 568.3Wm and depth of 45.6m. VES 2 nd revealed five (5) lithologies of curve type AAA with topsoil to a depth of 1.8m, 2 layer; fine sand with thickness of rd th 3m, 3 layer; medium sand with thickness of 12.0m, 4 layer; coarse sand with thickness of 28.0m, 5 layer coarse th th sand to infinity depth. The 4 layer is observed to be aquiferous with resistivity of 9871Wm at the depth of 45.2m. nd VES 3 revealed five (5) lithologies of curve type AAA with topsoil to a depth of 2.6m, 2 layer; fine sand with rd th thickness of 3.3m, 3 layer; medium sand with thickness of 9.5m, 4 layer; coarse sand with thickness of 31.3m, 5 th th layer coarse sand to infinity depth. The 4 layer is observed to be aquiferous with resistivity of 1541Wm at the depth of 46.7m. VES 4 revealed six (6) lithologies of curve type QQHA with topsoil to a depth of 1.7m, 2 layer; medium sand nd rd th with thickness of 2.2m, 3 layer; medium sand with thickness of 4.5m, 4 layer; fine sand with thickness of 11.7m, 5 th th th layer coarse sand with thickness of 25.9m, 6 layer; coarse sand to infinity depth. The 5 layer is observed to be aquiferous with resistivity of 1026Wm at the depth of 46.3m. VES 5 revealed six (6) lithologies of curve type AAKH nd rd with topsoil to a depth of 1.7m, 2 layer; fine sand with thickness of 2.2m, 3 layer; medium sand with thickness of th th 3.9m, 4 layer; medium sand with thickness of 8.0m, 5 layer coarse sand with thickness of 30.5m, 6 layer; coarse th th sand to infinity depth. The 5 layer is observed to be aquiferous with resistivity of 1081Wm at the depth of 46.3m. A recommendation of an average depth of 46m is to be drilled for all boreholes in the study area to yield potable and less vulnerable groundwater.

Publication Info:

Author: Dickenson, D.H. and Kekwaru, M.M.

Volume: 57

Issue: March

Published By: Journal of Mining and Geology, 2024-03-01