GAB | Flow system of the Hutton Sandstone in the northern Surat Basin, Australia

• Sue Vink
• Jim Underschultz
• Sam Guiton
• Juan Xu
• Vahab Honari

Newly acquired high-quality data are being used to reinterpret the Surat Basin flow systems of the Great Artesian Basin (GAB) in Australia. This paper revisits and updates previous interpretations of flow in the Hutton Sandstone with detailed analysis of the Dawson River area in the northern Surat Basin. Combining analysis of high-resolution permeability measurements with hydraulic head and hydrochemistry data supports the contention that there is significant flow towards the northeast, counter to the canonical regional flow conceptualisation of the GAB. The analysis in this work better identifies the likely discharge to be in the area that the Dawson River intersects the Hutton Sandstone. Heterogeneity in physical and hydrochemical properties suggests that local flowpaths are more complex than previously thought and, at least in this part of the Hutton aquifer, very little recharge contributes to flow deeper in the basin. These results provide a firm basis on which to refine and develop numerical hydrodynamic models of the basin, at least for the Hutton aquifer.