An assessment of the groundwater potentials of the farm with preliminary geophysical method and grain size analysis prior to the drilling of boreholes

Abstract

The study of groundwater potentials of the Owutu-Ogbu area, Southeastern Nigeria, has been carried out to delineate its availability of water. A geological study revealed that two main rock types, sandstone and shale, characterize the study area. The shale does not yield enough water, while the sandy area is the water-bearing zone. The sandstone outcrop trends N 55°E, dipping 160°SE with a dip of 60°, which facilitates the downward water motion by gravity. The presence of highly fractured and jointed sandstone is another attribute of the porous Afikpo sandstone in the Owutu-Amaigbo area. All the sample sizes are moderately sorted and moderately well sorted, with the exception of the sample at 120 ft. that is poorly sorted. At 90 ft., the sample is strongly positively skewed at 30 ft., 120 ft., 180 ft., and at the surface. At 60 ft., 150 ft., and 210 ft., they are nearly symmetrical. The samples are very coarse sand, except at 30 ft. and 210 ft. From the VES data, the aquifers were delineated between layers 3 and 4, ranging in depth from 50 to 60 m. Proper grain size analysis and VES interpretation show that a feasible borehole can be drilled at the southern end of the N 55°E trending sandy ridge.