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  • This report presents a summary of the groundwater and surface water hydrochemistry data release from the Howard East project conducted 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. This data release records the groundwater and surface water sample collection methods and hydrochemistry and isotope data from monitoring bores in the Howard East project area, Northern Territory (NT). The Howard East project is a collaborative study between Geoscience Australia and the NT Government. Hydrochemistry and isotope data were collected from existing bores in the Howard East area. The sampling methods, quality assurance/quality control procedures, analytical methods and results are included in this report and all hydrochemistry data are available for download from the link at right.

  • 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.

  • Waukarlycarly 1 is a stratigraphic well drilled in the southern part of the Canning Basin’s Waukarlycarly Embayment under Geoscience Australia’s Exploring for the Future program in collaboration with the Geological Survey of Western Australia to provide stratigraphic data for this poorly understood tectonic component. The well intersects a thin Cenozoic section, overlying Permian–Carboniferous fluvial clastics and glacial diamictites, with a thick pre-Carboniferous succession (855–2585 mRT) unconformably overlying the Neoproterozoic metasediments. Three informal siliciclastic intervals were defined based on the data from core lithology, well logs, fluid inclusions, chemical and mineral compositions; an Upper Sandstone (855–1348.1 mRT), a Middle Interval (1348.1–2443.4 mRT) and a Lower Sandstone (2443.4 –2585 mRT). The Middle Interval was further divided into six internal zones. Conventional methods were applied to interpret effective porosity, water saturation and elastic properties (Poisson’s ratio and Young’s modulus). Artificial neural network technology was employed on well logs to interpret the total organic carbon (TOC) content, pyrolysis products from the cracking of organic matter (S2), permeability, and mineral compositions. In the Upper Sandstone, average sandstone porosity and permeability are 17.9% and 464.5 mD and, 6.75 % and 10 mD in the Lower Sandstone. The Middle Interval claystone has an average porosity and permeability of 4.17 % and 0.006 mD, and average TOC content and S2 of 0.17 wt% and 0.047 mg HC/g rock with maximum values of 0.66 wt% and 0.46 mg HC/g rock. Average Poisson’s ratio and Young’s modulus of the claystone are 0.154 and 9.81 GPa. Correlations of mineral compositions, petrophysical, geomechanical and geochemical properties of the Middle Interval have been conducted. Young’s modulus and Poisson’s ratio are well correlated with the contents of key minerals, including Quartz, carbonates and TotalClay. Although TOC content is low at Waukarlycarly 1, hydrocarbon generation and migration have occurred elsewhere in the Waukarlycarly Embayment. The helium response just above the Neoproterozoic basement in the FIS profile is not associated with the hydrocarbon responses implying that these fluids have different sources.

  • 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.

  • Improvements in discovery and management of minerals, energy and groundwater resources are spurred along by advancements in surface and subsurface imaging of the Earth. Over the last half decade Australia has led the world in the collection of regionally extensive airborne electromagnetic (AEM) data coverage, which provides new constraints on subsurface conductivity structure. Inferring geology and hydrology from conductivity is non-trivial as the conductivity response of earth materials is non-unique, but careful calibration and interpretation does provide significant insights into the subsurface. To date utility of this new data is limited by its spatial extent. The AusAEM survey provides conductivity constraints every 12.5 m along flight lines with no constraints across vast areas between flight lines spaced 20 km apart. Here we provide a means to infer the conductivity between flight lines as an interim measure before infill surveys can be undertaken. We use a gradient boosted tree machine learning algorithm to discover relationships between AEM conductivity models across northern Australia and other national data coverages for three depth ranges: 0–0.5 m, 9–11 m and 22–27 m. The predictive power of our models decreases with depth but they are nevertheless consistent with our knowledge of geological, landscape evolution and climatic processes and an improvement on standard interpolation methods such as kriging. Our models provide a novel complementary methodology to gridding/interpolating from AEM conductivity alone for use by the mining, energy and natural resource management sectors. <b>Citation: </b>Wilford J., Ley-Cooper Y., Basak S., & Czarnota K., 2022. High resolution conductivity mapping using regional AEM survey and machine learning. In: Czarnota, K. (ed.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, https://dx.doi.org/10.26186/146380.

  • 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 study was commissioned by Geoscience Australia (GA) to produce a report on source rock maturity and maceral/organoclast assemblages for a suite of rock samples from from the MinEx CRC National Drilling Initiative (NDI) Carrara 1 drill hole in the Northern Territory, Australia. 25 samples consisting of 24 drill core samples and 1 drill cutting sample were studied using organic petrological methods to evaluate the organic matter type, content, thermal maturity and hydrocarbon potential. Vitrinite was absent in all the samples and variable amounts of bitumen was present throughout the stratigraphic section studied. Fluorescing lamalginite was present in the upper part of the section and no bioclasts were detected in the samples from the lower section. Vitrinite reflectance equivalents calculated from bitumen reflectance indicated that upper part of the section containing lamalginite is early to mid-mature and the lower part of the section is over-mature. Good potential for liquid hydrocarbons may exist in the upper part of the section and the overmature lower part of the stratigraphic section could be gas prone.

  • 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.

  • The Officer Basin spanning South Australia and Western Australia is the focus of a regional stratigraphic study being undertaken as part of the Exploring for the Future (EFTF) program, an Australian Government initiative dedicated to increasing investment in resource exploration in Australia. Despite numerous demonstrated oil and gas shows, the Officer Basin remains a frontier basin for energy exploration with significant uncertainties due to data availability. Under the EFTF Officer-Musgrave Project, Geoscience Australia acquired new geomechanical rock property data from forty core samples in five legacy stratigraphic and petroleum exploration wells that intersected Paleozoic and Neoproterozoic aged intervals. These samples were subjected to unconfined compressive rock strength tests, Brazilian tensile strength tests and laboratory ultrasonic measurements. Petrophysical properties were also characterised via X-ray computerised tomography scanning, grain density and porosity-permeability analysis. Accurate characterisation of static geomechanical rock properties through laboratory testing is essential. In the modern exploration environment, these datasets are a precompetitive resource that can simplify investment decisions in prospective frontier regions such as the Officer Basin. Appeared in The APPEA Journal 62 S385-S391, 13 May 2022

  • Geoscience Australia, in collaboration with state governments, will be carrying out airborne electromagnetic (AEM) surveys in western South Australia, southern NT and eastern WA during 2022. This scientific research is being carried out to obtain data that will enhance understanding of geology and natural resources of the region. This information will support future resource management decision-making. This survey has been expanded into Western Australia with funding from the Geological Survey of Western Australia, combined with valuable in-kind support from the South Australian and Northern Territory geological surveys. <p>