<div>The Australian Government's Data Driven Discoveries program, in collaboration with the Geological Survey of Queensland, has collected 1715 km of deep crustal seismic data across the Adavale Basin in South-Central Queensland. The L215 Adavale Basin Deep Crustal Seismic Survey was conducted between April and July 2023. The survey acquired 7 regional seismic lines, including 23GA-A1 (550 km), 23GA-A2 (196 km), 23GA-A3 (262 km), 23GA-A4 (94 km), 23GA-A5 (239 km), 23GA-A6 (161 km), and 23GA-A7 (213 km) across the basin. The acquisition of these lines occurred both during the day and night near the towns of Adavale, Charleville, Augathella, Blackall, westward towards Windorah, and north beyond Jericho.</div><div><br></div><div>The Adavale Basin Deep Crustal Seismic Survey complements previous work completed under the Data Driven Discoveries Program, including the Adavale Basin 2D Reprocessed Seismic Data Package (eCat No. 149018) and the newly defined chemostratigraphic framework for the basin (Riley et al., 2023, eCat No. 147773). The survey will deliver a significant uplift in regional shallow and deep crustal seismic information for the Adavale Basin, providing a modern, high-fold dataset that will enhance understanding of the basin's stratigraphy, hydrogeology, resource potential, and underground salt storage opportunities.</div><div><br></div><div><strong>The raw shot gather data acquired during the survey are now available from Geoscience Australia. To request this data, please email clientservices@ga.gov.au and include the reference 'eCat#149289' in your message.</strong></div>

<div>As part of the Data Driven Discoveries program, Geoscience Australia and the Geological Survey of Queensland collaborated to re-examine legacy well cuttings for a chemostratigraphic study. The aim was to identify opportunities for resource discovery in the Devonian-aged Adavale Basin in south-central Queensland by conducting a chemostratigraphic study to define regional stratigraphic correlations in a structurally complex basin with limited well penetrations. A total of 1,489 cutting samples were analysed for whole-rock geochemistry, as well as subsets of samples for whole-rock mineralogy and/or carbonate carbon and oxygen isotopes, from a whole-rock sample. The purpose was to establish new chemostratigraphic correlations across the basin independently, using data from 10 wells that sampled the Adavale Basin.</div>

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.

Statements of existing knowledge are compiled for known mineral, coal, hydrocarbon and carbon capture and storage (CCS) resources and reserves in the Adavale Basin. This data guide illustrates the current understanding of the distribution of these key resource types within the Adavale Basin region based on trusted information sources. It provides important contextual information on the Adavale Basin and where additional details on discovered resources can be found. So far, mineral deposits have not been found in the Adavale Basin. There are no coal deposits found in the basin itself, but 6 large coal deposits exist in the overlying basins in the Adavale Basin region. Historically, some small conventional gas resources have been found in the basin. Currently, there are no commercial reserves or available resources identified in the Adavale Basin itself. There are no active or planned carbon capture and storage (CCS) projects in the Adavale basin.

Publicly available geological data in the Adavale Basin region are compiled to produce statements of existing knowledge for natural hydrogen, hydrogen storage, coal and mineral occurrences. This data guide also contains an assessment of the potential for carbon dioxide (CO2) geological storage and minerals in the basin region. Geochemical analysis of gas samples from petroleum boreholes in the basin shows various concentrations of natural hydrogen. However, the generation mechanism of the observed natural hydrogen concentration is still unknown. The Adavale Basin also has the potential for underground hydrogen storage in the Boree Salt. Given the depth of the Boree Salt (wells have intersected the salt at depths below 1800 m) and the high fluid pressure gradient in the basin, the construction of underground salt caverns should include consideration of stability and volume shrinkage. Mineral occurrences are all found in the basins overlying the Adavale region. However, they are small (thousands of tonnes range) and not currently of economic interest. The Adavale Basin has potential for base and precious metal deposits due to suitable formation conditions, but the depth of the basin makes exploration and mining difficult and expensive. There are no identified occurrences or resources of coal in the Adavale Basin. Given the depth of the basin, extraction of any identified coal would probably be uneconomic, with the potential exception of coal seam gas extraction. An assessment of CO2 geological storage also shows prospective storage areas in the Eromanga Basin within the Adavale Basin region in the Namur-Murta and Adori-Westbourne play intervals.

<div>The Australian Government's Trusted Environmental and Geological Information (TEGI) program is a collaboration between Geoscience Australia and the CSIRO that aims to provide access to baseline geological and environmental data and information for strategically important geological basins. The initial geological focus is on the north Bowen, Galilee, Cooper, Adavale, and their overlying basins. This paper presents seven stratigraphic frameworks from these basin regions that underpin groundwater, environmental and resource assessments, identify intervals of resource potential, and can assist in management of associated risks to groundwater resources and other environmental assets. The construction of stratigraphic frameworks for this program builds upon existing lithostratigraphic schemes to capture the current state of knowledge. The frameworks incorporate play divisions for resource and hydrogeological assessments. A total of 33 play intervals are defined for the north Bowen, Galilee, Cooper, Adavale, and their overlying basins, using chronostratigraphic principles. Where possible, unconformities and flooding surfaces are used to define the lower and upper limits of plays. Data availability and temporal resolution are considered in capturing significant changes in gross depositional environments. The results from this work enable the consistent assessment of shared play intervals between basins, and also highlight uncertainties in the age and correlation of lithostratigraphic units, notably in the Galilee and north Bowen Basins.</div> This presentation was given at the 2023 Australasian Exploration Geoscience Conference (AEGC) 13-18 March, Brisbane (https://2023.aegc.com.au/)

<div>Lateral variation in maturity of potential Devonian source rocks in the Adavale Basin have 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>&nbsp;</div><div>The models were constructed used geological information from well completion reports to assign formation tops and stratigraphic ages to then forward-model the evolution of geophysical parameters. The rock parameters, including facies, temperature, organic geochemistry/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>&nbsp;</div><div>The results correspond relatively well with published heat flow predictions, however a few wells show possible localised heat effects that differ from the overall basin average. The models indicate full maturation of the Devonian source rocks with generation occurring during the Carboniferous and again during the Late Cretaceous. Any potential accumulations may be trapped in Devonian sandstone, limestone and mudstone units, as well as overlying younger sediments of the Mesozoic Eromanga Basin. Accumulations could be trapped by localised deposits of the Cooladdi Dolomite and other marine, terrestrial clastic and evaporite units around the 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 the Adavale Basin with potential either for tight or shale gas in favourable areas from the Log Creek Formation and Bury Limestone.</div> This Abstract was submitted/presented to the 2023 Australian Exploration Geoscience Conference 13-18 Mar (https://2023.aegc.com.au/)

<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>

<div>The Trusted Environmental and Geological Information (TEGI) Program (2021-2023) was a multi-disciplinary program that brought together the geology, energy resources, groundwater, carbon and hydrogen storage, mineral occurrences, surface water and ecology for four Australian basin regions. This talk covers how the team leveraged their varied scientific expertise to deliver integrated scientific outcomes for the North Bowen, Galilee, Cooper and Adavale basin regions. This talk highlights the approach and importance of meaningful engagement with those that live in, work in, rely on and care for the regions. The story of the TEGI program outlines how a committed team, collaborating across Australia’s leading scientific organisations, delivered genuine impact during a time of political change.</div><div><br></div>

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.