The petroleum systems summary report provides a compilation of the current understanding of petroleum systems for the McArthur Basin, including the prospective Beetaloo Sub-basin. The contents of this report are also available via the Geoscience Australia Portal at https://portal.ga.gov.au/, called The Petroleum Systems Summary Assessment Tool (Edwards et al., 2020). Three summaries have been developed as part of the Exploring for the Future (EFTF) program (Czarnota et al., 2020); the McArthur Basin, the Canning Basin, and a combined summary of the South Nicholson Basin and Isa Superbasin region. The petroleum systems summary reports aim to facilitate exploration by summarising key datasets related to conventional and unconventional hydrocarbon exploration, enabling a quick, high-level assessment the hydrocarbon prospectivity of the region.

This report provides an initial summary of the hydrogeochemistry of the McBride Basalt Province (MBP) and Nulla Basalt Province (NBP) of the Upper Burdekin Region of North Queensland, completed as part of Exploring for the Future (EFTF)—an eight year, $225 million Australian Government funded geoscience data and information acquisition program focused on better understanding the potential mineral, energy and groundwater resources across Australia. Groundwater hydrogeochemistry studies can improve system understanding by reflecting host formation compositions and groundwater processes. These studies also provide regional baseline groundwater datasets that can inform environmental monitoring, resource use and decision making. During 2017 and 2018 Geoscience Australia collected 38 groundwater samples and 80 surface water samples (including quality control samples) to evaluate groundwater system processes including potential flow paths, recharge and groundwater-surface water-interactions. These surveys were conducted across three months of fieldwork, sampling water for a comprehensive suite of hydrogeochemical parameters. The present report includes surface water and groundwater data and information on: 1) sampling sites; 2) field physicochemical parameters (EC, pH, Eh, DO and T); 3) field measurements of total alkalinity (HCO3-); 4) laboratory results of major anion and cation results; 5) laboratory results for isotopes of water (δ18O and δD), DIC (δ13C), and dissolved strontium (87Sr/86Sr); and 6) hydrogeochemical maps representing the spatial distribution of these parameters. Pending analyses include: CFCs, SF6 and radiogenic isotopes δ14C and δ36Cl. Analysis that were largely below detection limit include: trace element concentrations, dissolved sulfide (S2-), ferrous iron (Fe2+), and dissolved sulfate (affecting sampling of δ34S and δ18O). This study demonstrates that hydrogeochemistry surveys, with full suites of chemical parameters including isotopes, can reveal fundamental groundwater system processes such as groundwater flow paths, groundwater recharge and groundwater-surface water interactions. The chemical ‘fingerprints’ identified here indicate groundwater flow paths are largely restricted to within the MBP and NBP aquifers, which have little interaction with adjacent and underlying non-basaltic rocks. The results also indicate groundwater is largely recharged from rainfall in higher elevations of the basalt provinces, with variable rainfall inputs to groundwater from lower elevation and rivers along flow paths. Groundwater-surface water interactions show several chemical signatures linking groundwater to springs, tributary rivers and the Burdekin River. Results from the Upper Burdekin Hydrogeochemistry Survey for the MBP and NBP have been plotted and mapped with initial interpretations presented below. Further detailed interpretation of this hydrogeochemistry data will be the focus of future publications. This data release is part in a series of staged outputs from the EFTF program. Relevant data, information and images are available through the Geoscience Australia website.

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.

Long-period magnetotelluric (MT) data allow geoscientists to investigate the link between mineralisation and lithospheric-scale features and processes. In particular, the highly conductive structures imaged by MT data appear to map the pathways of large-scale palaeo-fluid migration, the identification of which is an important element of several mineral system models. Given the importance of these data, governments and academia have united under the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) to collect long-period MT data across the continent on a ~55 km-spaced grid. Here, we use AusLAMP data to demonstrate the MT method as a regional-scale tool to identify and select prospective areas for mineral exploration undercover. We focus on the region between Tennant Creek in the Northern Territory and east of Mount Isa in Queensland. Our results image major conductive structures up to 150 km deep in the lithosphere, such as the Carpentaria Conductivity Anomaly east of Mount Isa. This anomaly is a significant lithospheric-scale conductivity structure that shows spatial correlations with a major suture zone and known iron oxide–copper–gold deposits. Our results also identify similar features in several under-explored areas that are now considered to be prospective for mineral discovery. These observations provide a powerful means of selecting frontier regions for mineral exploration undercover.. <b>Citation:</b> Duan, J., Kyi, D., Jiang, W. and Costelloe, M., 2020. AusLAMP: imaging the Australian lithosphere for resource potential, an example from northern Australia. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

The Ordovician to Cretaceous Canning Basin of Western Australia is an underexplored prospective onshore petroleum basin with proven petroleum systems currently producing on a small-scale. The Canning Basin has recently become a site of interest for unconventional hydrocarbon exploration, with several formations within deeper basin depocentres being investigated for resources and estimates that suggest it may have the largest shale gas potential in Australia. Modern petroleum resource evaluation generally depends on an understanding of both local and regional stresses, which are a primary control over the formation and propagation of induced fractures. Presently, there are significant gaps in our understanding of these factors within the Canning Basin. This study characterises the regional stress regime of the onshore Canning Basin and presents detailed models of present-day stress within the subsurface. These allow for the identification of significant stress heterogeneities and natural barriers to fracture propagation. Wireline data interpretation reveals a variable present-day state of stress in the Canning Basin. An approximately NE-SW regional present-day maximum horizontal stress orientation is interpreted from observed wellbore failure in image logs, in broad agreement with both the Australian Stress Map and previously published earthquake focal mechanism data. One-dimensional mechanical earth models constructed for intervals from 15 Canning Basin petroleum wells highlight the relationship between lithology and stress. This study describes significant changes in stress within and between lithological units due to the existence of discrete mechanical units, forming numerous inter- and intra- formational stress boundaries likely to act as natural barriers to fracture propagation, particularly within units currently targeted for their unconventional resource potential. Broadly, a strike-slip faulting stress regime is interpreted through the basin, however, when analysed in detail there are three distinct stress zones identified.: 1) a transitional reverse- to strike-slip faulting stress regime in the top ~1 km of the basin, 2) a strike-slip faulting stress regime from ~1 km to ~3.0 km depth, and 3) a transitional strike-slip to normal faulting regime at depths greater than ~3.0 km. This study is a component of the Australian Government’s Exploring for the Future (EFTF) initiative, which is focused on gathering new data and information about the resource potential concealed beneath the surface across northern Australia. Appeared online in the Australian Journal of Earth Sciences 17 Feb 2021

NDI Carrara 1 is a deep stratigraphic drill hole (~1751m) completed in 2020 as part of the MinEx CRC National Drilling Initiative (NDI) in collaboration with Geoscience Australia and the Northern Territory Geological Survey. It is the first test of the Carrara Sub-basin, a depocentre newly discovered in the South Nicholson region based on interpretation from seismic surveys (L210 in 2017 and L212 in 2019) recently acquired as part of the Exploring for the Future program. The drill hole intersected approximately 1100 m of Proterozoic sedimentary rocks uncomformably overlain by 630 m of Cambrian Georgina Basin carbonates. This report presents quantitative X-ray diffraction data undertaken by Geoscience Australia on selected rock samples, collected at roughly 4 m intervals.

Geoscience Australia, in collaboration with state government agencies, has been collecting magnetotelluric (MT) data as part of the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) for several years. This program aims to map the electrical resistivity of the rock layers, at depths from ten kilometres to hundreds of kilometres, across the entire continent. AusLAMP sites are each about 55 km apart from each other. Locations are chosen in consultation with landholders and other stakeholders to minimise impacts and avoid disturbance.MT data is collected using sensors that record naturally occurring variations of the Earth’s magnetic and electric fields. The equipment does not produce or transmit and signals. After four to six weeks the equipment is retrieved and the site restored to its original condition.

The AusArray program aims to install small temporary passive seismic stations every 200 km across Australia. The seismic stations will passively measure small natural vibrations that travel through the Earth to help scientists understand the distribution and composition of rocks beneath the ground. Seismometers are sensitive instruments used to measure small natural vibrations that travel through the Earth caused by earthquakes, waves breaking on the shore and even wind. The data collected are analysed to create a three-dimensional model of the Earth’s subsurface. Passive seismic data can be used to model the Earth‘s structure, which is used to infer the geological history and assess the resource potential and natural hazards of the region.

This Record documents the efforts of the Geological Survey of Victoria (GSV) and Geoscience Australia (GA) in compiling a geochronology (age) compilation for Victoria, describing both the dataset itself and the process by which it is incorporated into the continental-scale Isotopic Atlas of Australia. The Isotopic Atlas draws together age and isotopic data from across the country and provides visualisations and tools to enable non-experts to extract maximum value from these datasets. Data is added to the Isotopic Atlas in a staged approach with priorities determined by GA- and partner-driven focus regions and research questions. This dataset, which was primarily compiled by GSV and has been supplemented with data compiled by GA during the 2013–2017 Stavely Project, is a foundation for the second phase of the Exploring for the Future initiative over 2020–2024, particularly the Darling-Curnamona-Delamerian Project.

This Record presents new Sensitive High Resolution Ion Micro Probe (SHRIMP) in situ monazite U–Pb geochronological results from the East Tennant area that were obtained in March 2022 as part of Geoscience Australia’s (GA) Exploring for the Future (EFTF) program. Three samples were targeted for monazite geochronology in order to constrain the timing of metamorphism and ductile deformation in the East Tennant area. Monazites in cordierite schist from the Alroy Formation in drill hole NDIBK01 (NDIBK01.300) yielded a weighted mean 207Pb/206Pb age of 1843.6 ± 6.1 Ma (95% confidence). Paragneiss from the Alroy Formation in drill hole NDIBK10 (NDIBK10.009) yielded monazites that returned a weighted mean 207Pb/206Pb crystallisation age of 1843.5 ± 5.1 Ma. Sparse monazites in sample NDIBK04.300, a garnet phyllite from drill hole NDIBK04, yielded a weighted mean 207Pb/206Pb crystallisation age of 1831 ± 28 Ma. These ages, from samples distributed throughout the East Tennant area, are interpreted to constrain the timing of an episode of low pressure, medium-grade metamorphism and coeval deformation.