- © 2016 Geological Society of South Africa
An aquifer in the semi-arid environment of Sutherland, South Africa is examined. The characterization of the saturated geological unit was completed by mapping associated dolerite dykes and fractured outcrops of Beaufort Group sedimentary rocks. This was complimented by pumping tests in order to better understand the fracture connectivity that was found to decrease with distance from a prominent dyke. Groundwater samples and precipitation samples in the study area were analysed for stable isotopes. Drill chips of selected boreholes were examined in order to also better understand the nature of the subsurface at the contact of the dolerite and a suspected subsurface feature identified through satellite imagery. The results are combined into a conceptual geohydrological model to gain insight into the groundwater flow dynamics of the area. Findings suggest preferential recharge occurs in the study area with higher hydraulic infiltration related to the river beds and fracture sets in the study area.