Which aquifers feed the iconic spring systems of the Great Artesian Basin and what can these springs reveal about the history and resilience of Australia's groundwater resources?
The springs of the Great Artesian Basin (GAB) are important groundwater-dependent ecosystems. They support unique plant and animal communities, hold cultural significance for Aboriginal peoples, and provide insights into the condition and movement of groundwater across the GAB.
This project aims to improve confidence in spring source aquifer attribution and better understand the vulnerability of spring systems to climate change, groundwater extraction and other human activities. Thee work forms part of a broader collaborative research initiative led by CSIRO, Geoscience Australia, the Queensland Department of Local Government, Water and Volunteers, ANSTO and The University of Queensland.
The UQ component of the project focuses on the application of environmental tracers and hydrogeochemical 'fingerprinting' techniques to identify the groundwater sources feeding spring complexes across Queensland's section of the Great Artesian Basin. By analysing the unique chemical and isotopic signatures preserved within groundwater, researchers are effectively using water to reveal its own history.
Field campaigns conducted across the Surat and Eromanga sub-basins sampled springs and groundwater bores from multiple spring complexes. Water samples were collected for major ion chemistry, stable isotopes, strontium isotopes and cosmogenic isotope analysis, with additional sampling undertaken for dissolved gases, noble gases and supporting geological investigations. A major focus of the research is the use of strontium isotopes (⁸⁷Sr/⁸⁶Sr) as a fingerprinting tool for aquifer attribution. When combined with groundwater chemistry, stable isotopes and geological data, these tracers allow researchers to distinguish between water sourced from key Great Artesian Basin aquifers including the Hutton Sandstone, Hooray Sandstone and Precipice Sandstone.
Importantly, the project highlights the value of integrating tracer data with three-dimensional geological models, hydrogeological mapping and geophysical information. This combined approach enables a more robust understanding of groundwater flow pathways and strengthens confidence in conceptual models used to manage groundwater resources.
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