The Australian Government, through the National Water Infrastructure Development Fund, commissioned Geoscience Australia to undertake a 3-year project ‘Assessing the Status of Groundwater in the Great Artesian Basin’. The overall aim of the project was to analyse existing and new geoscientific data acquired by the project to improve understanding of the hydrogeological system and water balance in the GAB. In conjunction, the project assessed satellite based technologies for monitoring groundwater storage and level change. This talk will discuss some of the key results of the project. These include: an updated hydrogeological framework for the GAB, mapping aquifer and aquitard properties, geometry and extent; revised groundwater recharge rate estimates in the eastern GAB groundwater intake beds; new groundwater system conceptual models of groundwater recharge processes and groundwater flow; an assessment of the Gravity Recovery and Climate Experiment (GRACE) satellite derived groundwater storage change estimates for the GAB; and Interferometric Synthetic Aperture Radar (InSAR) satellite data, for detecting changes in groundwater levels.

This web service provides access to geological, hydrogeological and hydrochemical digital datasets that have been published by Geoscience Australia for the Great Artesian Basin (GAB).

This web service provides access to geological, hydrogeological and hydrochemical digital datasets that have been published by Geoscience Australia for the Great Artesian Basin (GAB).

This report presents palynological data compiled and analysed as part of Geoscience Australia’s ‘Assessing the Status of Groundwater in the Great Artesian Basin’ project, commissioned by the Australian Government through the National Water Infrastructure Fund – Expansion. Diverse historic nomenclature within the Great Artesian Basin (GAB) Jurassic‒Cretaceous succession in different parts of the GAB makes it difficult to map consistently GAB resources across borders, at a basin-wide scale, in order to provide a geological and hydrogeological framework to underpin effective long-term management of GAB water resources. The study undertaken by MGPalaeo, in collaboration with Geoscience Australia, examined 706 wells across the GAB and compiled 407 wells, having Jurassic‒Cretaceous succession, with reviewed palynology data (down to total depth). This initial palynology data review allowed identification of new data samples from 20 wells (within the 407 wells) in Queensland and South Australia to fill data and knowledge gaps within the Jurassic‒Cretaceous GAB succession. This study resulted in: 1) a summary compilation of existing palynology data on 407 wells selected to create a regional framework between the Surat, eastern Eromanga and western Eromanga basins, to help regional correlations across the GAB, 2) a review of several different palynology zonation schemes and adaptation to a single consistent scheme, applying the scheme of Price (1997) for the spore pollen zonation and Partridge (2006) for the marine zonation, 3) updated stratigraphic charts across the Surat, Eromanga and Carpentaria basins, 4) identification of data and knowledge gaps, and 5) sampling of new palynology data to help fill some data and knowledge gaps identified in 13 key wells in the Surat Basin and 10 key wells in the Eromanga Basin. In the Surat Basin the new sampling program has targeted units within: the Evergreen Formation, Hutton Sandstone, Springbok Sandstone, Gubberamunda Sandstone, Orallo Formation, Mooga Sandstone, Bungil Formation. In the Eromanga Basin the sampling program targeted units within: the Poolowanna Formation, Hutton Sandstone, Adori Sandstone, Algebuckina Sandstone, Namur Sandstone and Hooray Sandstone. The study undertaken by MGPalaeo, in collaboration with Geoscience Australia, provides updated biostratigraphic information compiled in a standardised chronostratigraphic framework across the Surat, Eromanga and Carpentaria basins that mostly comprise the GAB. This work allows comparison of various geological, lithological, hydrogeological schemes. It provides links between various lithostratigraphic units, with different nomenclature, across jurisdictions. It also links these units to some key regional chronostratigraphic markers that can be used to generate consistent surfaces that correlate to aquifer and aquitard boundaries. The compilation of legacy and newly sampled and analysed palynology data allows refinement of a regional chronostratigraphic framework that can be used to map a common Mesozoic play interval scheme across all the resource types, for basin-scale assessments of groundwater, hydrocarbons, carbon capture and storage, and mineral potential. From this correlation of time equivalent geological units deposited in different environments, it is then possible to map internal lithological variations in stratigraphic facies within sequences that influence hydraulic properties and connectivity within and between aquifers across the GAB. The updated geometry and variability mapping within and between aquifers will help refine the conceptual hydrogeological model, to assess how aquifers and aquitards are connected within the GAB. The revised conceptual hydrogeological model can facilitate an improved understanding of potential impacts from exploitation of sub-surface resources in the basin, providing a basis for more robust water balance estimates.

This data package, completed as part of Geoscience Australia’s National Groundwater Systems (NGS) Project, presents results of the second iteration of the 3D Great Artesian Basin (GAB) and Lake Eyre Basin (LEB) (Figure 1) geological and hydrogeological models (Vizy & Rollet, 2023) populated with volume of shale (Vshale) values calculated on 2,310 wells in the Surat, Eromanga, Carpentaria and Lake Eyre basins (Norton & Rollet, 2023). This provides a refined architecture of aquifer and aquitard geometry that can be used as a proxy for internal, lateral, and vertical, variability of rock properties within each of the 18 GAB-LEB hydrogeological units (Figure 2). These data compilations and information are brought to a common national standard to help improve hydrogeological conceptualisation of groundwater systems across multiple jurisdictions. This information will assist water managers to support responsible groundwater management and secure groundwater into the future. This 3D Vshale model of the GAB provides a common framework for further data integration with other disciplines, industry, academics and the public and helps assess the impact of water use and climate change. It aids in mapping current groundwater knowledge at a GAB-wide scale and identifying critical groundwater areas for long-term monitoring. The NGS project is part of the Exploring for the Future (EFTF) program—an eight-year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program. The program seeks to inform decision-making by government, community, and industry on the sustainable development of Australia's mineral, energy, and groundwater resources, including those to support the effective long-term management of GAB water resources. This work builds on the first iteration completed as part of the Great Artesian Basin Groundwater project (Vizy & Rollet, 2022; Rollet et al., 2022), and infills previous data and knowledge gaps in the GAB and LEB with additional borehole, airborne electromagnetic and seismic interpretation. The Vshale values calculated on additional wells in the southern Surat and southern Eromanga basins and in the whole of Carpentaria and Lake Eyre basins provide higher resolution facies variability estimates from the distribution of generalised sand-shale ratio across the 18 GAB-LEB hydrogeological units. The data reveals a complex mixture of sedimentary environments in the GAB, and highlights sand body development and hydraulic characteristics within aquifers and aquitards. Understanding the regional extents of these sand-rich areas provides insights into potential preferential flow paths, within and between the GAB and LEB, and aquifer compartmentalisation. However, there are limitations that require further study, including data gaps and the need to integrate petrophysics and hydrogeological data. Incorporating major faults and other structures would also enhance our understanding of fluid flow pathways. The revised Vshale model, incorporating additional boreholes to a total of 2,310 boreholes, contributes to our understanding of groundwater flow and connectivity in the region, from the recharge beds to discharge at springs, and Groundwater Dependant Ecosystems (GDEs). It also facilitates interbasinal connectivity analysis. This 3D Vshale model offers a consistent framework for integrating data from various sources, allowing for the assessment of water use impacts and climate change at different scales. It can be used to map groundwater knowledge across the GAB and identify areas that require long-term monitoring. Additionally, the distribution of boreholes with gamma ray logs used for the Vshale work in each GAB and LEB units (Norton & Rollet, 2022; 2023) is used to highlight areas where additional data acquisition or interpretation is needed in data-poor areas within the GAB and LEB units. The second iteration of surfaces with additional Vshale calculation data points provides more confidence in the distribution of sand bodies at the whole GAB scale. The current model highlights that the main Precipice, Hutton, Adori-Springbok and Cadna-owie‒Hooray aquifers are relatively well connected within their respective extents, particularly the Precipice and Hutton Sandstone aquifers and equivalents. The Bungil Formation, the Mooga Sandstone and the Gubberamunda Sandstone are partial and regional aquifers, which are restricted to the Surat Basin. These are time equivalents to the Cadna-owie–Hooray major aquifer system that extends across the Eromanga Basin, as well as the Gilbert River Formation and Eulo Queen Group which are important aquifers onshore in the Carpentaria Basin. The current iteration of the Vshale model confirms that the Cadna-owie–Hooray and time equivalent units form a major aquifer system that spreads across the whole GAB. It consists of sand bodies within multiple channel belts that have varying degrees of connectivity' i.e. being a channelised system some of the sands will be encased within overbank deposits and isolated, while others will be stacked, cross-cutting systems that provide vertical connectivity. The channelised systemtransitions vertically and laterally into a shallow marine environment (Rollet et al., 2022). Sand-rich areas are also mapped within the main Poolowanna, Brikhead-Walloon and Westbourne interbasinal aquitards, as well as the regional Rolling Downs aquitard that may provide some potential pathways for upward leakage of groundwater to the shallow Winton-Mackunda aquifer and overlying Lake Eyre Basin. Further integration with hydrochemical data may help groundtruth some of these observations. This metadata document is associated with a data package including: • Seventeen surfaces with Vshale property (Table 1), • Seventeen surfaces with less than 40% Vshale property (Table 2), • Twenty isochore with average Vshale property (Table 3), • Twenty isochore with less than 40% Vshale property (Table 4), • Sixteen Average Vshale intersections of less than 40% Vshale property delineating potential connectivity between isochore (Table 5), • Sixteen Average Vshale intersections of less than 40% Vshale property delineating potential connectivity with isochore above and below (Table 6), • Seventeen upscaled Vshale log intersection locations (Table 7), • Six regional sections showing geology and Vshale property (Table 8), • Three datasets with location of boreholes, sections, and area of interest (Table 9).

This web service provides access to geological, hydrogeological and hydrochemical digital datasets that have been published by Geoscience Australia for the Great Artesian Basin (GAB).

This report presents the results of an assessment of geoscience data and tools applied in the eastern Eromanga Basin to improve the hydrogeological conceptualisations. The assessment is one component of the Australian Government funded project ‘Assessing the Status of Groundwater in the Great Artesian Basin’. The results demonstrate that the application of existing and new geoscientific data and technologies has the potential to further improve our understanding of the Great Artesian Basin (GAB) hydrogeological system thus supporting the responsible management of basin water resources. Hydrogeological synthesis using airborne electromagnetic data, in conjunction with hydro- and chrono-stratigraphic data and well geological information, are effective at mapping the three dimensional distribution of the aquifers and aquitards. The results lead to an improved understanding of groundwater intake bed geometry, potential connectivity between aquifers, possible structural controls on groundwater flow paths, and plausible source of groundwater discharging as springs. In the southern part of the study area, the dominantly shale-rich Evergreen Formation is electrically conductive, but is locally resistive in places due to sand-rich facies. These areas allow hydraulic connectivity between the overlying and underlying Hutton and Precipice sandstone aquifers. Anticlinal folds and juxtaposed strata are observed on AEM traverses along the strike of the aquifer units, and includes the Hutton, Adori and Cadna-owie – Hooray sandstones. Abrupt folding and juxtaposed strata were interpreted as fault zones. Both structural features have the potential of controlling groundwater flow directions or groundwater storage compartmentalisation. The northern limits of Precipice Sandstone and Evergreen Formation are at Blackall and south of Barcaldine towns respectively. This zone also coincides with the southern edge of the east-west trending sub-surface Barcaldine Ridge where the basal Jurassic sequence abut against. On and north of the Barcaldine Ridge, the Cadna-owie – Hooray, Adori and Hutton sandstones are present. Mapping using AEM conductivity sections affirm that the Hutton Sandstone is the major aquifer in the northern part of the study area. The Poolowanna Formation, an age equivalent to the Evergreen Formation and Precipice Sandstone, is laterally extensive towards the northern part of the study area. This formation crops-out west of Lake Buchanan in the Great Dividing Range, but forms sub-crops elsewhere along the groundwater recharge areas. Numerous groundwater springs and spring clusters are present along the east and west of the outcropping sandstone hills in the Great Dividing Range. In the northern parts of the study area, source of groundwater for the springs are mainly derived from the Hutton Sandstone aquifers through either gravity-feed or lateral groundwater flow process. Polygonal faults mainly occur on conductive and fined-grained sedimentary units of the Rolling Downs Group. There is lack of observable evidence from AEM conductivity sections on the presence of polygonal faults to suggest preferential groundwater flows along these potential hydraulic conduits. Further investigation using ground based methods are needed to establish the presence of the faults and their hydraulic properties.

The Great Artesian Basin Research Priorities Workshop, organised by Geoscience Australia (GA), was held in Canberra on 27 and 28 April 2016. Workshop attendees represented a spectrum of stakeholders including government, policy, management, scientific and technical representatives interested in GAB-related water management. This workshop was aimed at identifying and documenting key science issues and strategies to fill hydrogeological knowledge gaps that will assist federal and state/territory governments in addressing groundwater management issues within the GAB, such as influencing the development of the next Strategic Management Plan for the GAB. This report summarises the findings out of the workshop.

<b>This data package is superseded by a second iteration presenting updates on 3D geological and hydrogeological surfaces across eastern Australia that can be accessed through </b><a href="https://dx.doi.org/10.26186/148552">https://dx.doi.org/10.26186/148552</a> The Australian Government, through the National Water Infrastructure Fund – Expansion, commissioned Geoscience Australia to undertake the project ‘Assessing the Status of Groundwater in the Great Artesian Basin’ (GAB). The project commenced in July 2019 and will finish in June 2022, with an aim to develop and evaluate new tools and techniques to assess the status of GAB groundwater systems in support of responsible management of basin water resources. While our hydrogeological conceptual understanding of the GAB continues to grow, in many places we are still reliant on legacy data and knowledge from the 1970s. Additional information provided by recent studies in various parts of the GAB highlights the level of complexity and spatial variability in hydrostratigraphic units across the basin. We now recognise the need to link these regional studies to map such geological complexity in a consistent, basin-wide hydrostratigraphic framework that can support effective long-term management of GAB water resources. Geological unit markers have been compiled and geological surfaces associated with lithostratigraphic units have been correlated across the GAB to update and refine the associated hydrogeological surfaces. Recent studies in the Surat Basin in Queensland and the Eromanga Basin in South Australia are integrated with investigations from other regions within the GAB. These bodies of work present an opportunity to link regional studies and develop a revised, internally consistent geological framework to map geological complexity across the GAB. Legacy borehole data from various sources, seismic and airborne electromagnetic (AEM) data were compiled, then combined and analysed in a common 3D domain. Correlation of interpreted geological units and stratigraphic markers from these various data sets are classified using a consistent nomenclature. This nomenclature uses geological unit subdivisions applied in the Surat Cumulative Management Area (OGIA (Office of Groundwater Impact Assessment), 2019) to correlate time equivalent regional hydrogeological units. Herein we provide an update of the surface extents and thicknesses for key hydrogeological units, reconciling geology across borders and providing the basis for a consistent hydrogeological framework at a basin-wide scale. The new surfaces can be used for facilitating an integrated basin systems assessment to improve our understanding of potential impacts from exploitation of sub-surface resources (e.g., extractive industries, agriculture and injection of large volumes of CO2 into the sub-surface) in the GAB and providing a basis for more robust water balance estimates. This report is associated with a data package including (Appendix A – Supplementary material): • Nineteen geological and hydrogeological surfaces from the Base Permo-Carboniferous, Top Permian, Base Jurassic, Base Cenozoic to the surface (Table 2.1), • Twenty-one geological and hydrogeological unit thickness maps from the top crystalline basement to the surface (Figure 3.7 to Figure 3.27), • The formation picks and constraining data points (i.e., from boreholes, seismic, AEM and outcrops) compiled and used for gridding each surface (Table 3.8).

<div>This document provides metadata for the gross depositional environment (GDE) interpretations that have been generated in support of the energy resource assessments under the Australia’s Future Energy Resources (AFER) project.&nbsp;&nbsp;</div><div>The AFER projects is part of Geoscience Australia’s Exploring for the Future (EFTF) Program—an eight year, $225 million Australian Government funded geoscience data and precompetitive information acquisition program 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 will help support a strong economy, resilient society and sustainable environment for the benefit of all Australians. The EFTF program is supporting Australia’s transition to a low emissions economy, industry and agriculture sectors, as well as economic opportunities and social benefits for Australia’s regional and remote communities. Further details are available at http://www.ga.gov.au/eftf.&nbsp;</div><div>The GDE data sets provide high level classifications of interpreted environments where sediments were deposited within each defined play interval in the Pedirka, Simpson and Western Eromanga basins. Twelve gross depositional environments have been interpreted and mapped in the study (Table 1). A total of 14 play intervals have been defined for the Pedirka, Simpson and Western Eromanga basins by Bradshaw et al. (2022, in press), which represent the main chronostratigraphic units separated by unconformities or flooding surfaces generated during major tectonic or global sea level events (Figure 1). These play intervals define regionally significant reservoirs for hydrocarbon accumulations or CO2 geological storage intervals, and often also include an associated intraformational or regional seal.&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</div><div>GDE interpretations are a key data set for play-based resources assessments in helping to constrain reservoir presence. The GDE maps also provide zero edges showing the interpreted maximum extent of each play interval, which is essential information for play-based resource assessments, and for constructing accurate depth and thickness grids.&nbsp;&nbsp;</div><div>GDE interpretations for the AFER Project are based on integrated interpretations of well log and seismic data, together with any supporting palynological data. Some play intervals also have surface exposures within the study area which can provide additional published paleo-environmental data. The Pedirka, Simpson and Western Eromanga basins are underexplored and contain a relatively sparse interpreted data set of 42 wells and 233 seismic lines (Figure 2). Well and outcrop data provide the primary controls on paleo-environment interpretations, while seismic interpretations constrain the interpreted zero edges for each play interval. The sparse nature of seismic and well data in the study area means there is some uncertainty in the extents of the mapped GDE’s.&nbsp;&nbsp;</div><div>The data package includes the following datasets:&nbsp;&nbsp;</div><div>Play interval tops for each of the 42 wells interpreted – provided as an ‘xlsx’ file.&nbsp;</div><div>A point file (AFER_Wells_GDE) capturing the GDE interpretation for each of the 14 play intervals in each of the 42 wells – provided as both a shapefile and within the AFER_GDE_Maps geodatabase.&nbsp;</div><div>Gross depositional environment maps for each of the 14 play intervals (note that separate GDE maps have been generated for the Namur Sandstone and Murta Formation within the Namur-Murta play interval, and for the Adori Sandstone and Westbourne Formation within the Adori-Westbourne play interval) – provided as both shapefiles and within the AFER_GDE_Maps geodatabase.&nbsp;</div><div>&nbsp;</div><div>These GDE data sets are being used to support the AFER Project’s play-based energy resource assessments in the Western Eromanga, Pedirka and Simpson basins.&nbsp;</div><div><br></div>