The @hydrogeology of the Barossa Basin, South Australia

Abstract

The Barossa Basin is a complex hydrogeological environment containing a sedimentary aquifer system surrounded and underlain by a dual porosity fractured rock aquifer. The hydraulic relationship between the fractured rock aquifer and the sedimentary aquifers is poorly understood. The difficulties in describing the movement of groundwater through dual porosity media such as a fractured rock aquifer are well documented. While groundwater flow in the sedimentary aquifers can be adequately described using porous media flow techniques in the Barossa Basin, our understanding of interconnectivity between individual sedimentary aquifers is again poor. The Basin itself is narrow and, immediately adjacent to the Stockwell Fault on the eastern side of the valley, relatively deep (~200 m). Sediments deposited into the trough consisted of mainly discontinuous sequences of overlapping sands and carbonaceous clays. This was followed by the deposition of gravels, sands and clays that form the Barossa Valley as it is today. Various authors have sub-divided the geology into individual hydrostratigraphical units. However, a review of the literature highlighted inconsistencies in the number of aquifers recognised, their exact spatial distribution within the Basin, and that there have been changes in nomenclature that are not satisfactorily described. This has resulted in some confusion that requires clarification ...