<div>This was the last of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop. Towards developing a 3D hydrogeological framework for Australia: A common chronostratigraphic framework for aquifers&nbsp;</div><div><br></div>

Australia is the driest inhabited continent on Earth, and groundwater is crucial to supporting many urban and rural communities, economic activities and environmental values. Geoscience Australia, the nation’s trusted advisor on Earth Science, is renewing a deliberate focus on national-scale hydrogeological challenges within the Exploring for the Future program. This will be accomplished by building upon Geoscience Australia’s historic legacy in groundwater studies, including the development of the 1987 national hydrogeological map. Updating the extents, data and scientific understanding of the regions depicted in this map, and bringing it into a version suitable for access and use in the 21st century, will address many limitations of the existing map and its accompanying knowledge base. This compilation of information on Australia’s major hydrogeological regions, including both geospatial analyses of national datasets and high-level summaries of scientific literature, provides for a clear and consistent synthesis of hydrogeological and related contextual information. Supporting the delivery of the National Water Initiative and National Groundwater Strategic Framework, the inventory will benefit multi-sector water users (agriculture, communities, industry and tourism) and the environment. This work will also directly assist prioritisation and decision-making for future investment, and focus groundwater research in the work programs of Geoscience Australia and potentially inform national hydrogeological research more broadly. <b>Citation: </b>Lewis S. J., Lai E. C. S., Flower C. & Lester J. E., 2022. Towards a national information inventory of Australia’s major hydrogeological regions. In: Czarnota, K (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/146974

A compilation of thematic summaries of 42 Australian Groundwater Provinces. These consistently compiled 42 summaries comprise the National Hydrogeological Inventory. The layer provides the polygons for each groundwater province in the inventory and thematic information for each province, including location and administration information, demographics, physical geography, surface water, geology, hydrogeology, groundwater, groundwater management and use, environment, land use and industry types and scientific stimulus.

<div>This report and associated data package provide a compilation of biostratigraphic summaries, borehole logs, and stratigraphic correlations for key boreholes across the Amadeus, Officer and Georgina basins in the Paleozoic‒Neoproterozoic Centralian Superbasin and in the underlying older Mesoproterozoic South Nicholson and southern McArthur basins, laying the groundwork for further studies. This study is part of Geoscience Australia’s National Groundwater Systems project in the Exploring for the Future (EFTF) program.</div><div>This work compiles publicly available borehole data to enhance regional stratigraphic understanding. Future studies should incorporate outcrop constraints, geophysical data, and additional geological dating, alongside collaboration with experts to validate sequence chronostratigraphic correlations. The stratigraphic framework aligns geological units with timeframes, enabling consistent interbasinal correlation to group aquifers and aquitards and sedimentary mapping across lithologies and time periods. This alignment supports the integration of hydrostratigraphic classifications, potentially revealing a more accurate model of water flow connectivity over geological time units. The compilation standardises borehole log interpretation and integrates geological and hydrogeological data, contributing to national databases, exploration guidance, improving groundwater understanding, and resource impact assessments for decision-making across various groundwater, energy and minerals disciplines.</div><div>The study builds on previous EFTF program work (e.g., Bradshaw et al., 2021; Khider et al., 2021; Carson et al., 2023; Anderson et al., 2023) and legacy studies across Australia, addressing challenges in understanding groundwater systems due to limited subsurface geology knowledge and fragmented data across jurisdictions. A nationally coordinated approach is essential, with well logs playing a key role in interpreting subsurface geology. The mapping process involves interpolating between surface outcrops and subsurface strata using borehole data, integrated with geophysical interpretations. The goal is to create a consistent 3D geological framework across time-equivalent basins and jurisdictions, enabling consistent groundwater system assessments and water flow path analysis at regional and national scales.</div><div>Although not intended to be a major re-interpretation of existing data, this stratigraphy review updates stratigraphic picks where necessary to ensure a consistent interpretation across the study area. This framework is based on the 13 Centralian Supersequences defined in Bradshaw et al. (2021). Using this framework, a revised stratigraphic chart is proposed in this study to align geological units across the Officer, Amadeus, and Georgina basins with the geological time scale (Gradstein et al., 2020), incorporating significant events, such as major glaciations, orogens and other tectonic movements. </div><div>This report aims to summarise the main biostratigraphic groups used, where they have been found, and provide a detailed list of the reports available. Existing biostratigraphic data from 142 boreholes in the Georgina, Amadeus, and Officer basins and underlying older southern McArthur and South Nicholson basins, were compiled to improve regional correlations, addressing data gaps identified in previous studies. Due to time constraints, only the five fossil groups found most in borehole data are included, such as trilobites, palynology, conodonts, stromatolites and small shelly fossils. However, outcrop data provides a much larger dataset and set of fossil groups and will need to be incorporated for future studies. Outcrop biostratigraphic data was excluded here, as the focus of this study was collating borehole data. Efforts were made to refine and update formation picks, ensuring consistency in correlations across larger areas. The correlation of geological units and their assignment to the corresponding 13 Centralian Supersequences in 272 key boreholes provide a foundational stratigraphic framework. Challenges include limited biostratigraphic data, diverse dating methods, and complex structural histories in the studied basins. Problems and inconsistencies in the input data or current interpretations are highlighted to suggest where further studies or investigations may be useful. Borehole correlation transects have been established across each of the basins (20 in total), displaying age data points along with formation picks and supersequence divisions. While these simple 2D transects may not capture the structural complexity of specific areas, they provide a broad overview of the interrelationships between different units across each basin.</div><div>The datasets compiled and used in this study are in Appendix A (Biostratigraphic data) and Appendix B (Borehole stratigraphic data).</div>

<div>The Lake Eyre surface water catchment covers around 1,200,000 km2 of central Australia, about one-sixth of the entire continent. It is one of the largest endorheic river basins in the world and contains iconic arid streams such as the Diamantina, Finke and Georgina rivers, and Cooper Creek. The Lake Eyre region supports diverse native fauna and flora, including nationally significant groundwater-dependent ecosystems such as springs and wetlands which are important cultural sites for Aboriginal Australians.</div><div><br></div><div>Much of the Lake Eyre catchment is underlain by the geological Lake Eyre Basin (LEB). The LEB includes major sedimentary depocentres such as the Tirari and Callabonna sub-basins which have been active sites of deposition throughout the Cenozoic. The stratigraphy of the LEB is dominated by the Eyre, Namba and Etadunna formations, as well as overlying Pliocene to Quaternary sediments.</div><div><br></div><div>The National Groundwater Systems Project, part of Geoscience Australia's Exploring for the Future Program (https://www.eftf.ga.gov.au/), is transforming our understanding of the nation's major aquifer systems. With an initial focus on the Lake Eyre Basin, we have applied an integrated geoscience systems approach to model the basin's regional stratigraphy and geological architecture. This analysis has significantly improved understanding of the extent and thickness of the main stratigraphic units, leading to new insights into the conceptualisation of aquifer systems in the LEB.</div><div><br></div><div>Developing the new understanding of the LEB involved compilation and standardisation of data acquired from thousands of petroleum, minerals and groundwater bores. This enabled consistent stratigraphic analysis of the major geological surfaces across all state and territory boundaries. In places, the new borehole dataset was integrated with biostratigraphic and petrophysical data, as well as airborne electromagnetic (AEM) data acquired through AusAEM (https://www.eftf.ga.gov.au/ausaem). The analysis and integration of diverse geoscience datasets helped to better constrain the key stratigraphic horizons and improved our overall confidence in the geological interpretations.</div><div><br></div><div>The new geological modelling of the LEB has highlighted the diverse sedimentary history of the basin and provided insights into the influence of geological structures on modern groundwater flow systems. Our work has refined the margins of the key depocentres of the Callabonna and Tirari sub-basins, and shown that their sediment sequences are up to 400 m thick. We have also revised maximum thickness estimates for the main units of the Eyre Formation (185 m), Namba Formation (265 m) and Etadunna Formation (180 m).</div><div><br></div><div>The geometry, distribution and thickness of sediments in the LEB is influenced by geological structures. Many structural features at or near surface are related to deeper structures that can be traced into the underlying Eromanga and Cooper basins. The occurrence of neotectonic features, coupled with insights from geomorphological studies, implies that structural deformation continues to influence the evolution of the basin. Structures also affect the hydrogeology of the LEB, particularly by compartmentalising groundwater flow systems in some areas. For example, the shallow groundwater system of the Cooper Creek floodplain is likely segregated from groundwater in the nearby Callabonna Sub-basin due to structural highs in the underlying Eromanga Basin.</div><div> Abstract submitted and presented at the 2023 Australian Earth Science Convention (AESC), Perth WA (https://2023.aegc.com.au/)

<div>This dataset presents results of a first iteration of a 3D geological model across the Georgina Basin, Beetaloo Sub-basin of the greater McArthur Basin and South Nicholson Basin (Figure 1), completed as part of Geoscience Australia’s Exploring for the Future Program National Groundwater Systems (NGS) Project. These basins are located in a poorly exposed area between the prospective Mt Isa Province in western Queensland, the Warramunga Province in the Northern Territory, and the southern McArthur Basin to the north. These surrounding regions host major base metal or gold deposits, contain units prospective for energy resources, and hold significant groundwater resources. The Georgina Basin has the greatest potential for groundwater.</div><div>&nbsp;</div><div>Geoscience Australia’s Exploring for the Future program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to net zero emissions, strong, sustainable resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government. More information is available at http://www.ga.gov.au/eftf and https://www.eftf.ga.gov.au/national-groundwater-systems.</div><div>&nbsp;</div><div>This model builds on the work undertaken in regional projects across energy, minerals and groundwater aspects in a collection of data and interpretation completed from the first and second phases of the EFTF program. The geological and geophysical knowledge gathered for energy and minerals projects is used to refine understanding of groundwater systems in the region.</div><div>&nbsp;</div><div>In this study, we integrated interpretation of a subset of new regional-scale data, which include ~1,900 km of deep seismic reflection data and 60,000 line kilometres of AusAEM1 airborne electromagnetic survey, supplemented with stratigraphic interpretation from new drill holes undertaken as part of the National Drilling Initiative and review of legacy borehole information (Figure 2). A consistent chronostratigraphic framework (Figure 3) is used to collate the information in a 3D model allowing visualisation of stacked Cenozoic Karumba Basin, Mesozoic Carpentaria Basin, Neoproterozoic to Paleozoic Georgina Basin, Mesoproterozoic Roper Superbasin (including South Nicholson Basin and Beetaloo Sub-basin of the southern McArthur Basin), Paleoproterozoic Isa, Calvert and Leichhardt superbasins (including the pre-Mesoproterozoic stratigraphy of the southern McArthur Basin) and their potential connectivity. The 3D geological model (Figure 4) is used to inform the basin architecture that underpins groundwater conceptual models in the region, constrain aquifer attribution and groundwater flow divides. This interpretation refines a semi-continental geological framework, as input to national coverage databases and informs decision-making for exploration, groundwater resource management and resource impact assessments.</div><div><br></div><div>This metadata document is associated with a data package including:</div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Nine surfaces (Table 1): 1-Digital elevation Model (Whiteway, 2009), 2-Base Cenozoic, 3-Base Mesozoic, 4-Base Neoproterozoic, 5-Base Roper Superbasin, 6-Base Isa Superbasin, 7-Base Calvert Superbasin, 8-Base Leichhardt Superbasin and 9-Basement.</div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Eight isochores (Table 4): 1-Cenozoic sediments (Karumba Basin), 2-Mesozoic sediments (Carpentaria and Eromanga basins), 3-Paleozoic and Neoproterozoic sediments (Georgina Basin), 4-Mesoproterozoic sediments (Roper Superbasin including South Nicholson Basin and Beetaloo Sub-basin), 5-Paleoproterozoic Isa Superbasin, 6-Paleoproterozoic Calvert Superbasin, 7-Paleoproterozoic Leichhardt Superbasin and 8-Undifferentiated Paleoproterozoic above basement.</div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Five confidence maps (Table 5) on the following stratigraphic surfaces: 1-Base Cenozoic sediments, 2-Base Mesozoic, 3-Base Neoproterozoic, 4-Base Roper Superbasin and 5-Combination of Base Isa Superbasin/Base Calvert Superbasin/Base Leichhardt Superbasin/Basement.</div><div>·&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Three section examples (Figure 4) with associated locations.</div><div>Two videos showing section profiles through the model in E-W and N-S orientation.</div>

<div><strong>Output Type:</strong> Exploring for the Future Extended Abstract</div><div><br></div><div><strong>Short abstract: </strong>Australia is the driest inhabited continent on Earth and relies heavily on groundwater to support communities, industries, ecosystems and cultural values. Despite groundwater resources transcending state and territory boundaries, each jurisdiction operates under different legislative frameworks, policies and water management approaches, and accordingly coordination between jurisdictions is crucial to achieving the common goal of water security. Improving the alignment of water strategies between states and territories requires a national coordination of data collation with common standards and integration of subsurface geology, using a consistent and up-to-date 3D hydrogeological framework for better understanding of groundwater systems and flow pathways at regional to national scales. Despite ever increasing data availability in each jurisdiction there is a lack of comprehensive knowledge regarding cross-jurisdictional sedimentary architecture, aquifer extents and hydraulic connections. Geoscience Australia, through the Exploring for the Future program, is developing a consistent national chronostratigraphic framework to underpin the development of 3D (hydro)geological models which can be used to standardise hydrogeological classifications, update borehole stratigraphy and provide a basis for integrating diverse geoscientific datasets. By collaborating with jurisdictions to harmonise 3D geology nationally through correlation with the geological time scale, aquifer boundaries can be updated and shared with other collaborators such as the Bureau of Meteorology to ensure that national groundwater datasets are updated with the latest geological knowledge. This chronostratigraphic method is suitable for sedimentary basins and provides a consistent platform to support effective resource assessment and management, infrastructure planning, and environmental impact assessment at regional and national scales.</div><div><br></div><div><strong>Citation: </strong>Rollet, N., Vizy, J., Norton, C.J., Hannaford, C., McPherson, A., Symington, N., Evans, T., Nation, E., Peljo, M., Bishop, C., Boronkay, A., Ahmad, Z., Szczepaniak, M., Bradshaw, B., Wilford, J., Wong, S., Bonnardot, M.A. &amp; Hope, J., 2024. Developing a 3D hydrogeological framework for Australia. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://doi.org/10.26186/149418 </div>

This was the third of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop - WaMSTeC: Water Monitoring and Standardisation Technical Committee National Industry Guidelines for hydrometric monitoring WaMSTeC GUIDELINE REVISIONS UPDATE FOR GROUNDWATER COMPONENTS: GROUNDWATER SUBCOMMITTEE

This was the first of five presentations held on 31 July 2023 as part of the National Groundwater Systems Workshop - A clear and consistent inventory of knowledge about Australia’s major hydrogeological provinces.

<div>The Exploring for the Future program is a world leading program, delivering public geoscientific data and information required to empower decision-makers and attract future investment in resource exploration and development. Geoscience Australia engaged Alluvium Consulting Australia to quantify the impact and value of groundwater activities and outputs to the quadruple bottom line through an evaluation of 2 case studies, namely: • National Hydrogeological Mapping • The Southern Stuart Corridor project. This involved understanding the impact pathways for these case studies and the collection of data to be used in a cost benefit analysis. The work sought to provide feedback to Geoscience Australia, stakeholder groups and the broader community on the value of Geoscience Australia’s groundwater activities. The case study evaluations were facilitated by a series of specific questions, which were developed to guide data collection and the building of a knowledge base around the impact and value of the work in each case study and associated outputs. The questions broadly fell under the following categories: 1. Uptake and Usage 2. Impact 3. Benefit These evaluations were framed around the program impact pathway developed for each case study. This is a description of how inputs are used to deliver activities, which in turn result in outcomes and impacts (changes) for stakeholders, including the environment. The primary means of data collection to help answer the key evaluation questions was through online workshops and interviews with key stakeholders for each case study. These were undertaken between March 10 and March 24, 2023. In these workshops and interviews, representatives from industry, community and government agencies were asked if they could identify instances where case study program outputs were used for particular purposes, such as prioritising research or investment, advising Members of Parliament, or education and training. These examples were then explored further to understand what outcomes and benefits were derived from the use of the case study outputs, and how critical were the case study outputs to achieving those outcomes and benefits</div>