Obiadi I.I, Onwuemesi A.G, Ani
Abstract
One of the common features of most rock bodies is the presence of discontinuities which are generally called fractures. Fractures result when applied stress overcomes the strength of the host rock. Their presences must be carefully studied as they significantly affect the engineering and strength properties of the rocks. Their presences also influence the hydraulic properties of rocks. Several tools and methods have been employed in the study of fractures both at the surface and subsurface. The Electrical Resistivity Tomography ERT method, a geophysical tool was used in this research to study and characterize fractures in the crystalline rocks at Igarra, SW Nigeria. The survey which spans a survey line of 100m and average subsurface depth of 18m imaged the presences of vertical to steepdipping discontinuities which are interpreted as fracture planes. These fracture planes extends beyond the 18m depth of investigation suggesting that the fractures are potential conduits for leachate transport and surface water run-off infiltration in the area. This has implication for waste management disposal design and siting, as the chances of bedrock and groundwater contamination is potentially high. Hence the fracture characteristics must be taken into consideration when waste disposal management policies are being formulated and implemented.