Some observations on the sedimentary framework of the Loxton-Bookpurnong region, South Australia as defined by borehole, ground and airborne geophysical data - implications for informing the development of groundwater interception schemes

Abstract

The construction of salt interception schemes (SIS) in the Riverland region of South Australia forms an integral part of a broader strategy to manage saline groundwater intrusion into the River Murray. Results from the inversion of airborne electromagnetic data provided some insight into the distribution and variability of the Loxton sands aquifer. These data indicated regional facies variations associated with the main barrier systems of this prograded strandline sedimentary sequence. The relevance of this information is being followed up in an examination of options for the Bookpurnong highland borefield. A program involving the acquisition and interpretation of neutron, gamma and inductive conductivity borehole logs, NanoTEM ground TEM traverses, and the analysis of HEM data was undertaken to better define the sedimentary and hydrogeological model of the area. This approach has been critical in explaining local scale changes in the sedimentary environment and elucidating reasons for the variable aquifer yield in the Loxton sands aquifer.