Delineating groundwater flowpaths using 14C dating in the upper loddon catchment, central Victoria.

Abstract

Radiocarbon dating of groundwater has been used to delineate flowpaths and calculate hydraulic conductivity as part of a detailed hydrogeological/hydrogeochemical study of the Tullaroop catchment in the Upper Loddon, central Victoria. The dating confirms that both the basalt and deep lead aquifers in the study area are recharged through scoria cones at volcanic eruption points. The radiocarbon dating also shows that flow paths in the basalt aquifer are complex since ages do not always increase downflow; any hydraulic conductivity calculations must take this into account. One anomalously old 14C date supports other hydrogeological evidence that suggests groundwater in the deep lead is trapped upflow of horsts created by ENE Cainozoic faults.