Katerigi town is of geologic importance because it host the contact between the older crystalline basement complex rocks (hardrocks) and the younger sedimentary formations (softrocks). There exists a clear transition from the basement complex terrain to the sedimentary rocks belonging to the Bida Basin. Detailed hydrogeological mapping as well as Schlumberger Vertical Electrical Sounding (VES) and Horizontal Resistivity Profiling (HRP) techniques were employed in the exploration for groundwater in the area. Results of the hydrogeological mapping indicate the basement portion of the study area is dominated by granite and gneiss while sedimentary terrain consists of sandstone belonging to the Bida Basin. The rosette diagram plot of outcrops joint shows a NNESSW fracturing and it is recommended that groundwater exploration within the basement portion in the area should concentrate on the NNESSW direction. The pseudovertical resistivity sections also confirm a NNESSW fracturing. The investigation of the subsurface lithology via VES and HRP also shows deep weathering and basement fracturing. These zones of deep weathering and basement fractures are high groundwater potential area. The NNESSW principal joint direction controls the weathering and groundwater flow in the basement portion, making it hydrogeologically important as sandstone aquifers from the sedimentary portion.
