Two-Dimensional Resistivity Imaging of Migmatized Gneiss Basement Rock in Kaduna Polytechnic Main Campus, Kaduna Nigeria
An environmental assessment was carried out in Kaduna Polytechnic to delineate and map the water bearing formations underlying some subsurface basement rocks that protrude on the surface as outcrops. There was a particular need to ascertain the extent of deformations of the migmatized gneiss basement complex at depths and obtain detailed geological information mainly for addressing environmental and engineering problems. To obtain a proper imaging of these geologic features, a 2-D Electrical Resistivity Tomography was adopted for the investigation. Data acquisition was achieved via six profiles spanning 200 m each, traversing parallel and even diagonally to the azimuth of the featured outcrops. The intent was to ascertain the depth and extent of weathering of the basement majorly overlain by unconsolidated materials. The tomographic images from the processed resistance data displayed intermingling of patches of low resistivity zones indicating highly saturated sections that may likely be aquifers and high resistivity zones in the overburden revealing shallow bedrock respectively. However, the study revealed that the Northern Nigerian basement complex is highly deformed due to weathering at depth and widely overlain by consolidated and unconsolidated materials. It also confirmed the convenience of the study area for engineering constructions.
KeywordsAquifer Basement outcrops Downthrown faults Electrical resistivity tomography Migmatized gneiss
- 2.Ward, S.H.: Resistivity and induced polarization methods in Geotechnical and environmental geophysics. In: Ward, S.H. (ed.) Society of Exploration Geophysics, vol. 1 pp. 147–189, Tulsa, Okla, (1990)Google Scholar
- 6.Loke, M.H.: Tutorial: 2D and 3D Electrical Imaging Surveys (2004). www.geoelectrical.com