This report, completed as part of Geoscience Australia’s Exploring for the Future Program National Groundwater Systems (NGS) Project, presents results of the second iteration of 3D geological and hydrogeological surfaces across eastern Australian basins. 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. The datasets incorporate infills of data and knowledge gaps in the Great Artesian Basin (GAB), Lake Eyre Basin (LEB), Upper Darling Floodplain (UDF) and existing data in additional basins in eastern Australia. The study area extends from the offshore Gulf of Carpentaria in the north to the offshore Bight, Otway, and Gippsland basins in the South and from the western edge of the GAB in the west to the eastern Australian coastline to the east. The revisions are an update to the surface extents and thicknesses for 18 region-wide hydrogeological units produced by Vizy & Rollet, 2022. The second iteration of the 3D model surfaces further unifies geology across borders and provides the basis for a consistent hydrogeological framework at a basin-wide, and towards a national-wide, scale. The stratigraphic nomenclature used follows geological unit subdivisions applied: (1) in the Surat Cumulative Management Area (OGIA - Office of Groundwater Impact Assessment, 2019) to correlate time equivalent regional hydrogeological units in the GAB and other Jurassic and Cretaceous time equivalent basins in the study area and (2) in the LEB to correlate Cenozoic time equivalents in the study area. Triassic to Permian and older basins distribution and thicknesses are provided without any geological and hydrogeological unit sub-division. Such work helps to (1) reconcile legacy and contemporary regional studies under a common stratigraphic framework, (2) support the effective management of groundwater resources, and (3) provide a regional geological context for integrated resource assessments. The 18 hydrogeological units were constructed using legacy borehole data, 2D seismic and airborne electromagnetic (AEM) data that were compiled for the first iteration of the geological and hydrogeological surfaces under the GAB groundwater project (Vizy & Rollet, 2022a) with the addition of: • New data collected and QC’d from boreholes (including petroleum, CSG [Coal Seam Gas], stratigraphic, mineral and water boreholes) across Australia (Vizy & Rollet, 2023a) since the first iteration, including revised stratigraphic correlations filling data and knowledge gaps in the GAB, LEB, UDF region (Norton & Rollet, 2023) with revised palynological constraints (Hannaford & Rollet 2023), • Additional AEM interpretation since the first iteration in the GAB, particularly in the northern Surat (McPherson et al., 2022b), as well as in the LEB (Evans et al., in prep), in the southern Eromanga Basin (Wong et al., 2023) and in the UDF region (McPherson et al., 2022c), and • Additional 2D seismic interpretation in the Gulf of Carpentaria (Vizy & Rollet, 2023b) and in the western and central Eromanga Basin (Szczepaniak et al., 2023). These datasets were then analysed and interpreted in a common 3D domain using a consistent chronostratigraphic framework tied to the geological timescale of 2020, as defined by Hannaford et al. (2022). Confidence maps were also produced to highlight areas that need further investigation due to data gaps, in areas where better seismic depth conversion or improved well formation picks are required. New interpretations from the second iteration of the 18 surfaces include (1) new consistent and regionally continuous surfaces of Cenozoic down to Permian and older sediments beyond the extent of the GAB across eastern Australia, (2) revised extents and thicknesses of Jurassic and Cretaceous units in the GAB, including those based on distributed thickness, (3) revised extents and thicknesses of Cenozoic LEB units constrained by the underlying GAB 3D model surfaces geometry. These data constraints were not used in the model surfaces generated for the LEB detailed inventory (Evans et al., 2023), and (4) refinements of surfaces due to additional seismic and AEM interpretation used to infill data and knowledge gaps. Significant revisions include: • The use of additional seismic data to better constrain the base of the Poolowanna-Evergreen formations and equivalents and the top of Cadna-owie Formation and equivalents in the western and central Eromanga Basin, and the extent and thicknesses of the GAB units and Cenozoic Karumba Basin in the Gulf of Carpentaria, • The use of AEM interpretations to refine the geometry of outcropping units in the northern Surat Basin and the basement surface underneath the UDF region, and • A continuous 3D geological surface of base Cenozoic sediments across eastern Australia including additional constraints for the Lake Eyre Basin (borehole stratigraphy review), Murray Basin (AEM interpretation) and Karumba Basin (seismic interpretation). These revisions to the 18 geological and hydrogeological surfaces will help improve our understanding on the 3D spatial distribution of aquifers and aquitards across eastern Australia, from the groundwater recharge areas to the deep confined aquifers. These data compilations and information brought to a common national standard help improve hydrogeological conceptualisation of groundwater systems across multiple jurisdictions to assist water managers to support responsible groundwater management and secure groundwater into the future. These 3D geological and hydrogeological modelled surfaces also provide a tool for consistent data integration from multiple datasets. These modelled surfaces bring together variable data quality and coverage from different databases across state and territory jurisdictions. Data integration at various scale is important to assess potential impact of different water users and climate change. The 3D modelled surfaces can be used as a consistent framework to map current groundwater knowledge at a national scale and help highlight critical groundwater areas for long-term monitoring of potential impacts on local communities and Groundwater Dependant Ecosystems. The distribution and confidence on data points used in the current iteration of the modelled surfaces highlight where data poor areas may need further data acquisition or additional interpretation to increase confidence in the aquifers and aquitards geometry. The second iteration of surfaces highlights where further improvements can be made, notably for areas in the offshore Gulf of Carpentaria with further seismic interpretation to better constrain the base of the Aptian marine incursion (to better constrain the shape and offshore extent of the main aquifers). Inclusion of more recent studies in the offshore southern and eastern margins of Australia will improve the resolution and confidence of the surfaces, up to the edge of the Australian continental shelf. Revision of the borehole stratigraphy will need to continue where more recent data and understanding exist to improve confidence in the aquifer and aquitard geometry and provide better constraints for AEM and seismic interpretation, such as in the onshore Carpentaria, Clarence-Moreton, Sydney, Murray-Darling basins. Similarly adding new seismic and AEM interpretation recently acquired and reprocessed, such as in the eastern Eromanga Basin over the Galilee Basin, would improve confidence in the surfaces in this area. Also, additional age constraints in formations that span large periods of time would help provide greater confidence to formation sub-divisions that are time equivalent to known geological units that correlate to major aquifers and aquitards in adjacent basins, such as within the Late Jurassic‒Early Cretaceous in the Eromanga and Carpentaria basins. Finally, incorporating major faults and structures would provide greater definition of the geological and hydrogeological surfaces to inform with greater confidence fluid flow pathways in the study area. 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 1.1), • Twenty-one geological and hydrogeological unit thickness maps from the top crystalline basement to the surface (Figure 3.1 to Figure 3.21), • The formation picks and constraining data points (i.e., from boreholes, seismic, AEM and outcrops) compiled and used for gridding each surface (Table 2.7). Detailed explanation of methodology and processing is described in the associated report (Vizy & Rollet, 2023).

<div>This Geoscience Australia Record summarises the collection, analysis and results of three Global Positioning System (GPS) campaign surveys conducted in 2015, 2016 and 2019 in the northern Surat Basin, Queensland, Australia. During each campaign, we collected at least seven continuous days of GPS observations at each of the 65 sites of a geodetic network established by Geoscience Australia in 2014. Our analysis of the collected GPS data reveals statistically significant downward vertical ground surface movement between 2015 and 2016, 2015 and 2019, or both, at 18 of the 65 geodetic sites. Two of the 18 sites have recorded downward vertical ground surface movement of more than 100 millimetres: SB36 near Miles (125 mm) and SB49 near Wandoan (218 mm). Further work is required to help better resolve the temporal and spatial pattern of ground surface movement in the northern Surat Basin. This could include further GPS campaign surveys, analysis of GPS data from continuously operating reference sites in south-east Queensland, and a detailed comparison of surface deformation observed with GPS and interferometric synthetic aperture radar (InSAR) data; extending on the work described in McCubbine et al. (2022).</div><div><br></div>

Publicly available groundwater data have been compiled to inform environmental, resource development and regulatory decisions in the Adavale Basin region. This web service summarises salinity, water levels, resource size, potential aquifer yield and surface water–groundwater interactions for the Eromanga Basin located within the Adavale Basin region.

Publicly available data was compiled to provide a common information base for resource development, environmental and regulatory decisions in the Eromanga Basin region. This data guide gives an example of how these data can be used to create the components of a workflow to identify unconventional hydrocarbon resource opportunities. The data guide is designed to support the data package that provide insights on unconventional hydrocarbon resources in the Eromanga Basin. The unconventional hydrocarbon assessment for the Eromanga Basin includes shale resources (shale oil and gas) and coal seam gas for 6 of the 9 geological intervals, termed plays – these intervals have been defined by Wainman et al. (2023a, 2023b). Tight gas was not assessed due to play intervals lying above the zone of significant overpressure zone (2,800 m below ground level) in the Cooper-Eromanga region. The assessment captures data from well completion reports and government data sources to inform the components required for unconventional hydrocarbons to be present in the Eromanga Basin. The assessment captures data from the Great Artesian Basin geological and hydrogeological surfaces update (Vizy and Rollet, 2022), the Queensland Petroleum Exploration Database (QPED) from the Geological Survey of Queensland (GSQ) Open Data Portal (2020a), the Petroleum Exploration and Production System of South Australia (PEPS, 2021) and Draper 2002. These datasets were used to map out gross depositional environments and their geological properties relevant for unconventional hydrocarbon assessments. The data are compiled at a point in time to inform decisions on resource development activities. The data guide will outline the play-based workflow for assessing unconventional hydrocarbon prospectivity. Each of the elements required for a prospective unconventional hydrocarbon system is explained and mapped. These data are integrated and merged to show the relative assessment of unconventional prospectivity across the basin, at both play interval and basin scale. As an example of assessments contained within the dataset, this data guide showcases the prospectivity of shale resources in the Birkhead Play interval.

Publicly available groundwater data have been compiled to provide a common information base to inform environmental, resource development and regulatory decisions in the Cooper Basin region. This data guide gives examples of how these data can be used. The data package included with this data guide captures existing knowledge of Eromanga Basin aquifers and their properties, including salinity, water levels, resource size, potential aquifer yield and surface water interactions. The methods used to derive these data for all Eromanga Basin aquifers in the Cooper Basin region are outlined in the associated metadata files. These are described in groundwater conceptualisation models (Gouramanis et al., 2023). The Eromanga Basin overlying the Cooper Basin includes 5 broadly defined aquifer intervals: from deepest to shallowest, these are the Poolowanna, Hutton, Adori, Cadna-owie-Hooray and Winton-Mackunda aquifers. Compiled data are assigned to these intervals and used to characterise groundwater systems at the basin scale. The data were compiled for a point-in-time to inform decisions on potential resource developments in the Basin. The available historical groundwater data can be used to assess the potential effects on groundwater. The data can also be used for other purposes, such as exploring unallocated groundwater resource potential. Data to January 2022 are used for this compilation.

Publicly available groundwater data have been compiled to inform environmental, resource development and regulatory decisions in the Adavale Basin region. This web service summarises salinity, water levels, resource size, potential aquifer yield and surface water–groundwater interactions for the Eromanga Basin located within the Adavale Basin region.

Publicly available data was compiled to provide a common information base for resource development, and environmental and regulatory decisions in the Eromanga Basin. This data guide gives examples of how these data can be used to create the components of a workflow to identify geological storage of carbon dioxide (CO2) opportunities. The data guide is designed to support the data package that provide insights on the geological storage of CO2 in the Eromanga Basin. The geological storage of CO2 assessment for the Eromanga Basin overlying the Cooper, Adavale and Galilee basins encompasses 6 of the 9 geological intervals, termed plays – these intervals have been defined by Wainman et al. (2023a, b). The assessment captures data from the Great Artesian Basin geological and hydrogeological surfaces update (Vizy and Rollet, 2022), Queensland Petroleum Exploration Database (QPED) from the Geological Survey of Queensland (GSQ) Open Data Portal (2020a), the Petroleum Exploration and Production System of South Australia (PEPS, 2021); Bradshaw et al. (2009) and Draper (2002) along with the scientific literature to inform the 4 components required for a prospective geological storage of CO2 system. These datasets are used to map out gross depositional environments and their geological properties relevant for geological storage of CO2 assessments. From these datasets, the following properties were evaluated and mapped across the basin: injectivity, storage efficiency, containment and structural complexity. The data are compiled at a point in time to inform decisions on resource development opportunities. The data guide outlines the play-based workflow for assessing geological storage of CO2 prospectivity. Each of the elements required for a prospective geological storage of CO2 system are explained and mapped. These data were merged and spatially multiplied to show the relative assessment of geological storage of CO2 prospectivity across the basin, both at a play interval and basin scale. As an example of assessments contained within the data package, this data guide showcases the geological storage of CO2 prospectivity of the Namur-Murta Play interval.

Publicly available data was compiled to provide a common information base for resource development, environmental and regulatory decisions in the Eromanga Basin region. This web service summarises shale resources and coal seam gas prospectivity of the Eromanga Basin.

Publicly available groundwater data have been compiled to provide a common information base to inform environmental, resource development and regulatory decisions in the Galilee Basin region. This web service summarises salinity, water levels, resource size, potential aquifer yield and surface water–groundwater interactions for the Eromanga Basin located within the Galilee Basin region.

Publicly available data was compiled to provide a common information base for resource development, environmental and regulatory decisions in the Eromanga Basin region. This web service summarises shale resources and coal seam gas prospectivity of the Eromanga Basin.