Publicly available geology data are compiled to provide a common information base for resource development, environmental and regulatory decisions in the Adavale Basin region. This data guide gives examples of how these data can be used and supports the data package that provides the existing knowledge of the key geological intervals of the Adavale Basin and the overlying Galilee, Eromanga and Lake Eyre basins. The key geological intervals identified by the Trusted Environmental and Geological Information (TEGI) Program for resource assessment and groundwater system characterisation are termed play intervals and hydrostratigraphic intervals respectively. The Adavale Basin includes 8 plays, which are consolidated into 1 hydrostratigraphic interval. Overlying the Adavale Basin are 5 play intervals of the Galilee Basin, which are consolidated into 3 hydrostratigraphic intervals; 9 play intervals of the Eromanga Basin, which are consolidated into 7 hydrostratigraphic intervals; and 1 Cenozoic play interval and 1 hydrostratigraphic interval for the Lake Eyre and other Cenozoic basins. The geological groups and formations included in the plays and hydrostratigraphic intervals are summarised in the stratigraphic charts of Wainman et al. (2023a). Gross depositional, depth structure and thickness maps are provided with 3D model and cross-sections summarising the geology of the Adavale Basin and the overlying basins. The mapped depths and thicknesses of the key intervals are used to inform resource assessments and provide the framework for assigning groundwater data to hydrostratigraphic intervals.

A large proportion of Australia’s onshore sedimentary basins remain exploration frontiers. Industry interest in these basins has recently increased due to the global and domestic energy demand, and the growth in unconventional hydrocarbon exploration. In 2016 and 2018, Geoscience Australia released an assessment of several central Australian basins that summarised the current status of geoscientific knowledge and petroleum exploration, and the key questions, for each basin. This publication provides a comprehensive assessment of the geology, petroleum systems, exploration status and data coverage for the Adavale Basin.

<div>A prerequisite to understanding the evolution and resource potential of a basin is to establish a reliable stratigraphic framework that enables the correlation of rock units across multiple depocentres. Establishing a stratigraphic model for the Adavale Basin is challenging due to its structurally complexity, lack of well penetration and its lateral changes in facies. Biostratigraphy appears broad-scale, and despite providing chronostratigraphic control for the Lower Devonian Gumbardo Formation when combined with U/Pb zircon geochronology, the rest of the Devonian succession is hampered by a lack of microfossil assemblages and their poor preservation. The aim of this study is to establish an independent chemostratigraphic correlation across the Adavale Basin using whole rock inorganic geochemistry. Within this study, a total of 1489 cuttings samples from 10 study wells were analysed by Inductively Coupled Plasma – Optical Emission Spectrometry and Inductively Coupled Plasma – Mass Spectrometry for whole rock geochemistry, in order to establish an independent chemostratigraphic zonation scheme. Based on key elemental ratios selected to reflect changes in feldspars, clay minerals and provenance, the Devonian-aged stratigraphy is characterised into four chemostratigraphic mega-sequences that encompass the Gumbardo Formation (Mega-sequence 1); the Eastwood Formation, the Log Creek Formation and the Lissoy Sandstone (Mega-sequence 2); the Bury Limestone and the Boree Salt formations (Mega-sequence 3); and the Etonvale and the Buckabie formations (Mega-sequence 4). These mega-sequences have been further subdivided into a series of chemostratigraphic sequences that can be correlated across the study wells, establishing a regional correlation framework.&nbsp;&nbsp;&nbsp;</div> This Paper was submitted/presented to the 2023 Australian Petroleum Production & Exploration Association (APPEA) Conference 15-18 May, (https://www.appea.com.au/appea-event/appea-conference-and-exhibition-2023/). <b>Journal Citation:</b> Riley David, Pearce Tim, Davidson Morven, Sirantoine Eva, Lewis Chris, Wainman Carmine (2023) Application of elemental chemostratigraphy to refine the stratigraphy of the Adavale Basin, Queensland. <i>The APPEA Journal</i><b> 63</b>, 207-219. https://doi.org/10.1071/AJ22108

Large-scale storage of commercially produced hydrogen worldwide is presently stored in salt caverns. Through the Exploring for the Future program, Geoscience Australia is identifying and mapping salt deposits in Australia that may be suitable for hydrogen storage. The Adavale Basin in central Queensland is home to the Boree Salt, which is the only known thick salt deposit in eastern Australia and has the potential to become a strategic resource for underground hydrogen storage. The Boree Salt primarily consists of halite and can be as much as 555 meters thick in certain wells. Geoscience Australia contracted CSIRO to conduct a geochemistry test on four salt core samples from the Boree 1 and Bury 1 wells to analyse potential organic matter. Seven sub-samples of dark and clean salt from each core were sent to CSIRO's organic geochemistry laboratory in Lindfield, NSW. The results indicated that no organic matter was found in the Boree Salt samples. Disclaimer Geoscience Australia has tried to make the information in this product as accurate as possible. However, it does not guarantee that the information is totally accurate or complete. Therefore, you should not solely rely on this information when making a commercial decision. This dataset is published with the permission of the CEO, Geoscience Australia.

Large-scale storage of commercially produced hydrogen worldwide is presently stored in salt caverns. Through the Exploring for the Future program, Geoscience Australia is identifying and mapping salt deposits in Australia that may be suitable for hydrogen storage. The Boree Salt in the Adavale Basin of central Queensland is the only known thick salt accumulation in eastern Australia, and represent potentially strategic assets for underground hydrogen storage. The Boree Salt consists predominantly of halite and can be up to 555 m thick in some wells. Geoscience Australia contracted CSIRO to conduct rock mechanics and petrophysical laboratory analyses on four Boree Salt whole cores from Boree 1 and Bury 1 wells. Four plugs extracted from the cores were tested to determine dry bulk density, grain density, gas porosity, permeability, Poisson's ratio and Young's Modulus, while two plugs underwent ultra-low permeability tests. Triaxial tests were carried out on the four samples at confining pressures of 10, 20, 30 and 40 MPa. The average dry bulk density and grain density were found to be 2.15 g/cm3 and 2.17 g/cm3, respectively. The average gas and total porosity were determined to be 0.98% and 1.0%, respectively, while the average permeability of the two samples from Boree 1 is 0.85 µD. The triaxial test results showed that the average Poisson's ratio was 0.188, and Young's modulus was 16.1 GPa. Further tests, such as the creep test, in-situ seal capacity test, and leaching tests, are required to determine the suitability of the Boree Salt for underground hydrogen storage. Disclaimer: Geoscience Australia has tried to make the information in this product as accurate as possible. However, it does not guarantee that the information is totally accurate or complete. Therefore, you should not solely rely on this information when making a commercial decision. This dataset is published with the permission of the CEO, Geoscience Australia.

Large-scale storage of commercially produced hydrogen worldwide is presently stored in salt caverns. Through the Exploring for the Future program, Geoscience Australia is identifying and mapping salt deposits in Australia that may be suitable for hydrogen storage. The Boree Salt in the Adavale Basin of central Queensland is the only known thick salt accumulation in eastern Australia, and represent potentially strategic assets for underground hydrogen storage. The Boree Salt consists predominantly of halite and can be up to 555 m thick in some wells. Geoscience Australia contracted CSIRO to conduct analyses four Boree Salt whole cores extracted from Boree 1 and Bury 1 wells. The tests were carried out to determine the seal capacity (mercury injection capillary pressure - MICP), mineralogy (X-ray diffraction - XRD), and inorganic geochemistry of the cores. The entire core sections were scanned using X-ray CT images. In addition, four plugs were taken from the cores and tested for dry bulk density, grain density, gas porosity, and permeability. Two plugs underwent ultra-low permeability tests. The MICP test suggests that the Boree Salt is a competent seal for hydrogen storage. Mineralogy testing (XRD) revealed that the Boree Salt samples primarily comprise halite (96.5%), minor anhydrite (1.32%) and dolomite (1.65%) with traces of quartz, calcite, sylvite and cristobalite. Inorganic geochemistry results show sodium (Na; 55.4% average) is the most abundant element. Further tests, such as the creep test, in-situ seal capacity test, and leaching tests, are required to determine the suitability of the Boree Salt for underground hydrogen storage. Disclaimer: Geoscience Australia has tried to make the information in this product as accurate as possible. However, it does not guarantee that the information is totally accurate or complete. Therefore, you should not solely rely on this information when making a commercial decision. This dataset is published with the permission of the CEO, Geoscience Australia.

<div>Geoscience Australia’s Onshore Basin Inventories project delivers a single point of reference and creates a standardised national basin inventory that provides a whole-of-basin catalogue of geology, petroleum systems, exploration status and data coverage of hydrocarbon-prone onshore Australian sedimentary basins. In addition to summarising the current state of knowledge within each basin, the onshore basin inventory reports identify critical science questions and key exploration uncertainties that may help inform future work program planning and decision making for both government and industry. Volume 1 of the inventory covers the McArthur, South Nicholson, Georgina, Wiso, Amadeus, Warburton, Cooper and Galilee basins and Volume 2 expands this list to include the Officer, Perth and onshore Canning basins. Under Geoscience Australia’s Exploring for the Future (EFTF) program, several new onshore basin inventory reports are being delivered. Upcoming releases include the Adavale Basin of southern Queensland, and a compilation report addressing Australia’s poorly understood Mesoproterozoic basins. These are supported by value-add products that address identified data gaps and evolve regional understanding of basin evolution and prospectivity, including petroleum systems modelling, seismic reprocessing and regional geochemical studies. The Onshore Basin Inventories project continues to provide scientific and strategic direction for pre-competitive data acquisition under the EFTF work program, guiding program planning and shaping post-acquisition analysis programs.</div>

<div>The Adavale Basin is located approximately 850 km west-northwest of Brisbane and southwest of Longreach in south-central Queensland. The basin system covers approximately 100,000 km2 and represents an Early to Late Devonian (Pragian to Famennian) depositional episode, which was terminated in the Famennian by widespread contractional deformation, regional uplift and erosion. </div><div>Burial and thermal history models were constructed for nine wells using existing open file data to assess the lateral variation in maturity and temperature for potential source rocks in the Adavale Basin, and to provide an estimate of the hydrocarbon generation potential in the region.</div>

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>Lateral variation in maturity of potential Devonian source rocks in the Adavale Basin has been investigated using nine 1D burial, thermal and petroleum generation history models, constructed using existing open file data. These models provide an estimate of the hydrocarbon generation potential of the basin. Total organic carbon (TOC) content and pyrolysis data indicate that the Log Creek Formation, Bury Limestone and shale units of the Buckabie Formation have the most potential as source rocks. The Log Creek Formation and the Bury Limestone are the most likely targets for unconventional gas exploration.</div><div>The models were constructed using geological information from well completion reports to assign formation tops and stratigraphic ages, and then forward model the evolution of geophysical parameters. The rock parameters, including facies, temperature, organic geochemistry and petrology, were used to investigate source rock quality, maturity and kerogen type. Suitable boundary conditions were assigned for paleo-heat flow, paleo-surface temperature and paleo-water depth. The resulting models were calibrated using bottom hole temperature and measured vitrinite reflectance data.</div><div>The results correspond well with published heat flow predictions, although a few wells show possible localised heat effects that differ from the basin average. The models indicate that three major burial events contribute to the maturation of the Devonian source rocks, the first occurring from the Late Devonian to early Carboniferous during maximum deposition of the Adavale Basin, the second in the Late Triassic during maximum deposition of the Galilee Basin, and the third in the Late Cretaceous during maximum deposition of the Eromanga Basin. Generation in the southeastern area appears to have not been effected by the second and third burial events, with hydrocarbon generation only modelled during the Late Devonian to early Carboniferous event. This suggests that Galilee Basin deposition was not significant or was absent in this area. Any potential hydrocarbon accumulations could be trapped in Devonian sandstone, limestone and mudstone units, as well as overlying younger sediments of the Mesozoic Eromanga Basin. Migration of the expelled hydrocarbons may be restricted by overlying regional seals, such as the Wallumbilla Formation of the Eromanga Basin. Unconventional hydrocarbons are a likely target for exploration in the Adavale Basin, with potential for tight or shale gas from the Log Creek Formation and Bury Limestone in favourable areas.</div>