Interpretation of the Thomson Orogen and its context within the Tasmanides of eastern Australia is hampered by vast areas of deep sedimentary cover which also mask potential relationships between central and eastern Australia. Within covered areas, basement drill cores offer the only direct geological information. This study presents new detrital zircon isotopic data for these drill cores and poorly understood outcropping units to provide new age and provenance information on the Thomson Orogen. Two distinct detrital zircon signatures are revealed. One is dominated by Grenvillian-aged (1300900 Ma) zircons with a significant peak at ~1180 Ma and lesser peak at ~1070 Ma. These age peaks, along with Lu-Hf isotopic compositions (median Hf(t) = +1.5), dominantly mantle-like 18O values (median = 5.53) and model ages of ~1.89 Ga, support a Musgrave Province (central Australia) source. The dominance of Grenvillian-aged material additionally points to deposition during the Petermann Orogney (570530 Ma) when the Musgrave Province was uplifted shedding abundant material to the Centralian Superbasin. Comparable age spectra suggest that parts of the Thomson Orogen were connected to the Centralian Superbasin during this period. We use the term `Syn-Petermann to describe this signature which is observed in two drill cores adjacent to the North Australian Craton and scattered units in the outcropping Thomson Orogen. The second signature marks a significant provenance shift and is remarkably consistent throughout the Thomson Orogen. Age spectra exhibit dominant peaks at 600560 Ma, lesser 1300900 Ma populations and maximum depositional ages of ~496 Ma. This pattern is termed the `Pacific Gondwana detrital zircon signature and is recognised throughout eastern Australia, Antarctica and central Australia. LuHf isotope data for Thomson Orogen rocks with this signature is highly variable with Hf(t) values between -49 and +10 and dominantly supracrustal 18O values suggesting input from different and more diverse source regions.

<p>The outcrop extent of the McBride Basalt Province, selected from the Queensland Detailed Surface Geology vector polygon mapping, March 2017. <p>© State of Queensland (Department of Natural Resources and Mines) 2017 Creative Commons Attribution

Building on newly acquired airborne electromagnetic and seismic reflection data during the Exploring for the Future (EFTF) program, Geoscience Australia (GA) generated a cover model across the Northern Territory and Queensland, in the Tennant Creek – Mount Isa (TISA) area (Figure 1; between 13.5 and 24.5⁰ S of latitude and 131.5 and 145⁰ E of longitude) (Bonnardot et al., 2020). The cover model provides depth estimates to chronostratigraphic layers, including: Base Cenozoic, Base Mesozoic, Base Paleozoic and Base Neoproterozoic. The depth estimates are based on the interpretation, compilation and integration of borehole, solid geology, reflection seismic, and airborne electromagnetic data, as well as depth to magnetic source estimates. These depth estimates in metres below the surface (relative to the Australian Height Datum) are consistently stored as points in the Estimates of Geophysical and Geological Surfaces (EGGS) database (Matthews et al., 2020). The data points compiled in this data package were extracted from the EGGS database. Preferred depth estimates were selected to ensure regional data consistency and aid the gridding. Two sets of cover depth surfaces (Bonnardot et al., 2020) were generated using different approaches to map megasequence boundaries associated with the Era unconformities: 1) Standard interpolation using a minimum-curvature gridding algorithm that provides minimum misfit where data points exist, and 2) Machine learning approach (Uncover-ML, Wilford et al., 2020) that allows to learn about relationships between datasets and therefore can provide better depth estimates in areas of sparse data points distribution and assess uncertainties. This data package includes the depth estimates data points compiled and used for gridding each surface, for the Base Cenozoic, Base Mesozoic, Base Paleozoic and Base Neoproterozoic (Figure 1). To provide indicative trends between the depth data points, regional interpolated depth surface grids are also provided for the Base Cenozoic, Base Mesozoic, Base Paleozoic and Base Neoproterozoic. The grids were generated with a standard interpolation algorithm, i.e. minimum-curvature interpolation method. Refined gridding method will be necessary to take into account uncertainties between the various datasets and variable distances between the points. These surfaces provide a framework to assess the depth and possible spatial extent of resources, including basin-hosted mineral resources, basement-hosted mineral resources, hydrocarbons and groundwater, as well as an input to economic models of the viability of potential resource development.

<div>This study investigates the feasibility of mapping potential groundwater dependent vegetation (GDV) at a regional scale using remote sensing data. Specifically, the Digital Earth Australia (DEA) Tasseled Cap Percentiles products, integrated with the coefficient of greenness and/or wetness, are applied in three case study regions in Australia to identify and characterise potential terrestrial and aquatic groundwater dependent ecosystems (GDE). The identified high potential GDE are consistent with existing GDE mapping, providing confidence in the methodology developed. The approach provides a consistent and rapid first-pass approach for identifying and assessing GDEs, especially in remote areas of Australia lacking detailed GDE and vegetation information.</div>

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).

Geoscience Australia is leading a regional evaluation of potential mineral, energy and groundwater resources through the Exploring for the Future (EFTF) program. This stratigraphic assessment is part of the Onshore Basin Inventories project, and was undertaken to understand Devonian-aged depositional systems and stratigraphy in Queensland’s Adavale Basin. Such data are fundamental for any exploration activities. Maximising the use of existing well data can lead to valuable insights into the regional prospectivity of sedimentary basins. Data from 53 Adavale Basin wells have been used to evaluate subsurface stratigraphy, depositional environments and hydrocarbon shows across the basin. Stratigraphic data from 26 representative wells, where the well intersected at least three Devonian stratigraphic units, are used to generate chronostratigraphic time-space charts and two-dimensional well correlations within, and between, different (northern, north central, central, west central, east central and southern) parts of the basin. The primary objectives of the study are: • stratigraphic gap analysis to identify geological uncertainties and data deficiencies in the areas of interest, • integrate the well data with Geoscience Australia’s databases (i.e., Australian Stratigraphic Units, Time Scale, Geochronology, STRATDAT, RESFACS),the Geological Survey of Queensland’s Datasets and publicly available (published and unpublished) research data and information, • determine the lithostratigraphic unit tops, log and lithology characterisations, depositional facies, boundary criteria, spatial and temporal distribution and regional correlations, • integrate key biostratigraphic zones and markers with geochronological absolute age dates to generate a chronostratigraphic Time-Space Diagram of the basin. This work improves the understanding of the chronostratigraphic relationships across the Adavale Basin. The age of the sedimentary successions of the basin have been refined using geochronology, biostratigraphy and lithostratigraphic correlation. The chronostratigraphic and biozonation chart of the Adavale Basin has been updated and the stratigraphic, biostratigraphic and hydrocarbon shows datasets will be available for viewing and download via the Geoscience Australia Portal (https://portal.ga.gov.au/restore/15808dee-efcd-428e-ba5b-59b0106a83e3).

<div>This Queensland Geological Record presents ten new Sensitive High Resolution Ion MicroProbe (SHRIMP) U–Pb zircon and monazite results obtained under the auspices of the Geological Survey of Queensland–Geoscience Australia (GSQ–GA) National Collaborative Framework (NCF) geochronology project between July 2017 and June 2018. These data were collected in support of ongoing regional mapping and geoscientific programs led by the GSQ in the Mount Isa region.&nbsp;</div><div><br></div><div><br></div><div><br></div><div><br></div><div><strong>Bibliographic reference:</strong></div><div>Kositcin, N., Lewis, C. J. Withnall, I. W., Slade, A. P., Sargent, S. and Hutton, L. J. 2023. Summary of results. Joint GSQ–GA Geochronology Project: Mount Isa region, 2017–2018. GSQ Record 2023/03. Geoscience Australia, Canberra. Record 2023/32, Geological Survey of Queensland. http://dx.doi.org/10.26186/147793</div>

<div>New Sensitive High Resolution Ion Microprobe (SHRIMP) U–Pb geochronological results for fifteen Proterozoic and late Paleozoic samples, thirteen from the Georgetown Region and two from the adjacent Cairns Region, are presented in this Record. Eleven of the samples are from cores of basement units intersected in drillholes that penetrated overlying rocks of the Karumba (Cenozoic) and Carpentaria (Mesozoic) basins. Three of these are gneisses from the undercover extension of the Yambo Subprovince (Etheridge Province) in the northeastern part of the Georgetown Region, four are of Mesoproterozoic granites from the Forsayth Subprovince (Etheridge Province) and Croydon Province farther south, and the remaining eight are from units forming part of the Carboniferous–Permian Kennedy Igneous Association, including two from surface outcrops in the Georgetown Region and two from surface outcrops in the adjacent Cairns Region.</div><div><br></div>

The Upper Burdekin Chloride Mass Balance Recharge web service depicts the recharge rates have been estimated at borehole locations in the Nulla and McBride basalt provinces. Using rainfall rates, rainfall chemistry and groundwater chemistry, the recharge rates have been estimated through the Chloride Mass Balance approach.

From June 23rd to November 4th 2016 Geotech Ltd. carried out a helicopter-borne geophysical survey over part of East Isa in Queensland (figure 1). Operations were based at Cloncurry, Queensland. The traverse lines were flown in an east to west (N 90° E azimuth) direction with 2km and 2.5km traverse line spacings, with three Tie lines flown perpendicular to the traverse lines. During the survey the helicopter was maintained at a mean altitude of 76 metres above the ground with an average survey speed of 90 km/hour. This allowed for an actual average EM Transmitter-receiver loop terrain clearance of 38 metres and a magnetic sensor clearance of 68 metres. The principal geophysical sensors included a versatile time domain electromagnetic (VTEMTMPlus) full receiver-waveform system, and a caesium magnetometer. Ancillary equipment included a GPS navigation system, laser and radar altimeters, and inclinometer. A total of 15697 line-kilometres of geophysical data were acquired during the survey. The electromagnetic system is a Geotech Time Domain EM (VTEMplus) with full receiver-waveform streamed data recording at 192 kHz. The "full waveform VTEM system" uses the streamed half-cycle recording of transmitter current and receiver voltage waveforms to obtain a complete system response calibration throughout the entire survey flight. The VTEM transmitter loop and Z-component receiver coils are in a concentric-coplanar configuration and their axes are nominally vertical. An X-component receiver coil is also installed in the centre of the transmitter loop, with its axis nominally horizontal and in the flight line direction. The receiver coils measure the dB/dt response, and a B-Field response is calculated during the data processing. In-field data quality assurance and preliminary processing were carried out on a daily basis during the acquisition phase. Preliminary and final data processing, including generation of final digital data products were undertaken from the office of Geotech Ltd. in Aurora, Ontario. A set of Conductivity Depth Images (CDI) were generated using EM Flow version 3.3, developed by Encom Technologies Pty Ltd. A total of forty-five (45) dB/dt Z component channels, starting from channel 4 (21 µsec) to channel 48 (10667 µsec), were used for the CDI calculation. An averaged waveform at the receiver was used for the calculation since it was consistent for the majority of the flights with minor deviation from the average. Digital data includes all electromagnetic and magnetic data, conductivity imaging products, mulitplots plus ancillary data including the waveform.