Groundwater is critical to Australia’s future economic development and is the only reliable water source for many regional and rural communities. It also sustains environmental and cultural assets including springs and groundwater-dependent ecosystems. The demand for groundwater in Australia is expected to increase with population growth, economic development and climate change. Geoscience Australia, in partnership with Commonwealth, State and Territory governments is delivering national and regional groundwater investigations through the Exploring for the Future (EFTF) Program to support water management decisions. Geoscience Australia’s groundwater studies apply innovative geoscience tools and robust geoscientific workflows to increase knowledge and understanding of groundwater systems and assessment of groundwater resource potential for economies, communities and the environment. Through integrating geological and hydrogeological data, airborne electromagnetic and ground-based geophysical, hydrogeochemical and remote sensing data, we have developed new geological and hydrogeological conceptual models and identified potential managed aquifer recharge sites in a number of areas across Northern Australia. The EFTF program is focussed on improving our understanding of Australia's groundwater through a National Groundwater Systems project as well as two regional-scale groundwater investigations in Southern Australia. We are commencing an inventory of Australia’s groundwater systems in onshore basins that includes a compilation and broad interpretation of hydrogeological information. This is the basis for the collation and curation of nationally seamless groundwater information to support informed decision making and water resource coordination across jurisdictions. All data and value-added products are freely available for public use via the Exploring for the Future Data Discovery portal (https://portal.ga.gov.au/). This Abstract was submitted to the 2022 Australasian Groundwater Conference 21-23 November (https://agc2022.com.au/)

<div>This is a conference abstract discussing the compilation of information for our consistent national understanding across the major hydrogeological regions of Australia. This work is a component of the National Groundwater Systems project within the Exploring for the Future program.</div>

<div>The ‘Major crustal boundaries of Australia’ data set synthesises more than 40 years of acquisition of deep seismic reflection data across Australia, where major crustal-scale breaks, often inferred to be relict sutures between different crustal blocks, have been interpreted in the seismic reflection profiles. The widespread coverage of the seismic profiles now provides the opportunity to construct a map of major crustal boundaries across Australia. Starting with the locations of the crustal breaks identified in the seismic profiles, geological (e.g. outcrop mapping, drill hole, geochronology, isotope) and geophysical (e.g. gravity, aeromagnetic, magnetotelluric, passive seismic) data are used to map the crustal boundaries, in map view, away from the seismic profiles. For some of these boundaries, a high level of confidence can be placed on the location, whereas the location of other boundaries can only be considered to have medium or low confidence. In other areas, especially in regions covered by thick sedimentary successions, the locations of some crustal boundaries are essentially unconstrained. </div><div>The ‘Major crustal boundaries of Australia’ map shows the locations of inferred ancient plate boundaries, and will provide constraints on the three dimensional architecture of Australia. It allows a better understanding of how the Australian continent was constructed from the Mesoarchean through to the Phanerozoic, and how this evolution and these boundaries have controlled metallogenesis. It is best viewed as a dynamic dataset, which will need to be refined and updated as new information, such as new seismic reflection data, becomes available.</div><div><br></div>