A `weighted geometric median’ approach has been used to estimate the median surface reflectance of the barest state (i.e., least vegetation) observed through Landsat-8 OLI observations from 2013 to September 2018 to generate a six-band Landsat-8 Barest Earth pixel composite mosaic over the Australian continent. The bands include BLUE (0.452 - 0.512), GREEN (0.533 - 0.590), RED, (0.636 - 0.673) NIR (0.851 - 0.879), SWIR1 (1.566 - 1.651) and SWIR2 (2.107 - 2.294) wavelength regions. The weighted median approach is robust to outliers (such as cloud, shadows, saturation, corrupted pixels) and also maintains the relationship between all the spectral wavelengths in the spectra observed through time. The product reduces the influence of vegetation and allows for more direct mapping of soil and rock mineralogy. Reference: Dale Roberts, John Wilford, and Omar Ghattas (2018). Revealing the Australian Continent at its Barest, submitted.

An estimate of the spectra of the barest state (i.e., least vegetation) observed from imagery of the Australian continent collected by the Landsat 5, 7, and 8 satellites over a period of more than 30 years (1983 – 2018). The bands include BLUE (0.452 - 0.512), GREEN (0.533 - 0.590), RED, (0.636 - 0.673) NIR (0.851 - 0.879), SWIR1 (1.566 - 1.651) and SWIR2 (2.107 - 2.294) wavelength regions. The approach is robust to outliers (such as cloud, shadows, saturation, corrupted pixels) and also maintains the relationship between all the spectral wavelengths in the spectra observed through time. The product reduces the influence of vegetation and allows for more direct mapping of soil and rock mineralogy. This product complements the Landsat-8 Barest Earth which is based on the same algorithm but just uses Landsat8 satellite imagery from 2013-2108. Landsat-8’s OLI sensor provides improved signal-to-noise radiometric (SNR) performance quantised over a 12-bit dynamic range compared to the 8-bit dynamic range of Landsat-5 and Landsat-7 data. However the Landsat 30+ Barest Earth has a greater capacity to find the barest ground due to the greater temporal depth. Reference: Exposed Soil and Mineral Map of the Australian Continent Revealing the Land at its Barest - Dale Roberts, John Wilford and Omar Ghattas Ghattas (2019). Nature Communications, DOI: 10.1038/s41467-019-13276-1. https://www.nature.com/articles/s41467-019-13276-1

NDI Carrara 1 is a deep stratigraphic drill hole 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. A comprehensive geochemical program designed to provide information about the region’s resource potential was carried out on samples collected at up to 4 meter intervals. This report presents part 1 of the data from Rock-Eval pyrolysis analyses undertaken by Geoscience Australia on selected rock samples to establish their total organic carbon content, hydrocarbon-generating potential and thermal maturity.

The Officer Basin in South Australia and Western Australia is the focus of a regional stratigraphic study being undertaken by the Exploring for the Future (EFTF) program, an Australian Government initiative dedicated to increasing investment in resource exploration in Australia. This data release provides data from new digital photography, X-ray Computerised Tomography (XCT) scanning, unconfined compressive strength (UCS) and tensile strength, laboratory ultrasonic testing, and gas porosity and permeability experiments for 41 samples from five legacy stratigraphic and petroleum exploration boreholes drilled within the Officer Basin. Additional low permeability tests were undertaken on select samples that were identified as being ultra-tight (permeability <1 µD). These samples were analysed at CSIRO Geomechanics and Geophysics Laboratory in Perth during April to June 2021.

<p>The Exploring for the Future program is an initiative by the Australian Government dedicated to boosting investment in resource exploration in Australia. The four-year program led by Geoscience Australia focusses on northern Australia and parts of South Australia to gather new data and information about the potential mineral, energy and groundwater resources concealed beneath the surface. As part of the Exploring for the Future program, this study aims to improve our understanding of the petroleum resource potential of northern Australia. As a component of this project, collaboration between the Onshore Energy Systems Branch, Geoscience Australia and the Northern Territory Geological Survey (NTGS) is designed to produce pre-competitive information to assist with the evaluation of the petroleum prospectivity of onshore Northern Territory basins. <p>Proterozoic basins of northern Australia including the McArthur Basin, the Isa Superbasin and the Isa Superbasin have the potential to host conventional oil and gas, in addition to unconventional shale gas and oil plays (Muir et al., 1980; Munson, 2014; Revie, 2016; Revie, 2017; Gorton & Troup, 2018). To date, work on the prospective petroleum systems in the McArthur Basin has focused principally on source rocks within the McArthur and Roper groups in the southern parts of the basin. However due to limited data availability, the spatial variability in source rock quality, type and thermal maturity remains poorly constrained across the region. In the South Nicholson region of Queensland and the Northern Territory, data from the Paleoproterozoic Isa Superbasin and the Mesoproterozoic South Nicholson Basin is extremely limited and a large proportion of the available data is old and of poor quality. To more comprehensively characterise these organic rich source rocks, higher resolution coverages of pre-competitive geochemical data is required (Gorton & Troup, 2018; Jarrett et al. 2018). <p>This data release contains the total organic carbon (TOC) content and Rock-Eval pyrolysis data of 314 samples selected from nine drill cores from the McArthur Basin, South Nicholson Basin and Isa Superbasin that are housed in the Northern Territory Geological Survey’s Darwin core repository. The wells include Glyde 1, Lamont Pass 3 (McArthur Basin), Brunette Downs 1, CRDD001, NTGS 00/1, NTGS 01/1, NTGS 02/1 (South Nicholson Basin), in addition to ND1 and ND2 (Isa Superbasin). This data was generated at the Isotope and Organic Geochemistry Laboratory at Geoscience Australia as part of the Exploring for the Future program. The results show that the McArthur Basin samples analysed contain source rocks with poor to fair oil and gas generative potential with variable thermal maturity from immature to early oil mature. The Isa Superbasin samples analysed have poor to good gas generative potential and the South Nicholson samples analysed have poor to excellent gas generative potential. Samples from the Walford Dolostone and the Mullera Formation are overmature and petroleum potential cannot be assessed from the results of this study. This data release provides additional information that can be used to characterise the organic richness, kerogen type and thermal maturity of source rocks in the Teena Dolostone, Barney Creek Formation and Lynott Formation of the McArthur Basin, the Walford Dolostone and Mount Les Siltstone of the Isa Superbasin, in addition to the Constance Sandstone and Mullera Formation of the South Nicholson Basin. This data is provided in preparation for future work to generate statistics quantifying the spatial distribution, quantity and quality of source rocks, providing important insights into the hydrocarbon prospectivity of northern Australian basins

As part of the Exploring for the Future Programme this study aims to improve our understanding of the petroleum resource potential of Northern Australia. As a component or this project, collaboration between the Onshore Energy Branch, Geoscience Australia and the Northern Territory Geological Survey (NTGS) is designed to produce pre-competitive information to assist with the evaluation of the petroleum prospectivity of onshore Northern Territory basins. This report characterises the organic richness, kerogen type and thermal maturity of source rocks in the Velkerri, Barney Creek, Wollogorang and McDermott formations of the McArthur Basin based on Rock-Eval pyrolysis data analysed at Geoscience Australia in the 2017 to 2018 financial year. This data is provided in preparation for future work to generate statistics quantifying the spatial distribution, quantity and quality of McArthur Basin source rocks, providing important insights into the hydrocarbon prospectivity of the basin.

This Geoscience Australia Record reports the findings of the Canning Basin Petroleum Systems Modelling Project. The southern, frontier portions of the Canning Basin have numerous potential hydrocarbon play opportunities, in particular unconventional gas plays, which remain untested. Of particular interest are Ordovician-aged petroleum systems. Geoscience Australia in collaboration with the Geological Survey of Western Australia acquired an 872 km long 2D seismic line across the south and south-west Canning Basin in 2018, and drilled the 2680 m stratigraphic hole Barnicarndy 1 in the Barnicarndy Graben to further develop the understanding of hydrocarbon prospectivity in these frontier regions. As part of the Exploring for the Future program Geoscience Australia contracted GNS Science to construct ten 1D petroleum systems models and one 2D model across the frontier southern parts of the basin. The aim was to combine interpretation of the newly acquired seismic data with interpretation of legacy and new well data, in particular organic geochemical data, to improve the understanding of the burial and thermal history, trap formation, generation and migration of hydrocarbons in the southern, frontier parts of the Canning Basin. This Record is a compilation of the work completed by GNS Science International Limited and the reports containing new data collected and analyzed relevant to the petroleum systems modelling.

Collection of mineral, gem, meteorite, fossil (including the Commonwealth Palaeontological Collection) and petrographic thin section specimens dating back to the early 1900s. The collection is of scientific, historic, aesthetic, and social significance. Geoscience Australia is responsible for the management and preservation of the collection, as well as facilitating access to the collection for research, and geoscience education and outreach. Over 700 specimens from the collection are displayed in our public gallery . The collection contains: • 15,000 gem, mineral and meteorite specimens from localities in Australia and across the globe. • 45,000 published palaeontological specimens contained in the Commonwealth Palaeontological Collection (CPC) mainly from Australia. • 1,000,000 unpublished fossils in a ‘Bulk Fossil’ collection. • 250,000 petrographic thin section slides. • 200 historical geoscience instruments including: cartography, geophysical, and laboratory equipment." <b>Value: </b>Specimens in the collection are derived from Geoscience Australia (GA) surveys, submissions by researchers, donations, purchases and bequests. A number of mineral specimens are held on behalf of the National Museum of Australia. <b>Scope: </b>This is a national collection that began in the early 1900s with early Commonwealth surveys collecting material across the country and British territories. The mineral specimens are mainly from across Australia, with a strong representation from major mineral deposits such as Broken Hill, and almost 40% from the rest of the world. The majority of fossils are from Australia, with a small proportion from lands historically or currently under Australian control, such as Papua New Guinea and the Australian Antarctic Territory.

The Geoscience Australia Rock Properties database stores the result measurements of scalar and vector petrophysical properties of rock and regolith specimens and hydrogeological data. Oracle database and Open Geospatial Consortium (OGC) web services. Links to Samples, Field Sites, Boreholes. <b>Value:</b> Essential for relating geophysical measurements to geology and hydrogeology and thereby constraining geological, geophysical and groundwater models of the Earth <b>Scope:</b> Data are sourced from all states and territories of Australia

Remotely sensed datasets provide fundamental information for understanding the chemical, physical and temporal dynamics of the atmosphere, lithosphere, biosphere and hydrosphere. Satellite remote sensing has been used extensively in mapping the nature and characteristics of the terrestrial land surface, including vegetation, rock, soil and landforms, across global to local-district scales. With the exception of hyper-arid regions, mapping rock and soil from space has been problematic because of vegetation that either masks the underlying substrate or confuses the spectral signatures of geological materials (i.e. diagnostic mineral spectral features), making them difficult to resolve. As part of the Exploring for the Future program, a new barest earth Landsat mosaic of the Australian continent using time-series analysis significantly reduces the influence of vegetation and enhances mapping of soil and exposed rock from space. Here, we provide a brief background on geological remote sensing and describe a suite of enhanced images using the barest earth Landsat mosaic for mapping surface mineralogy and geochemistry. These geological enhanced images provide improved inputs for predictive modelling of soil and rock properties over the Australian continent. In one case study, use of these products instead of existing Landsat TM band data to model chromium and sodium distribution using a random forest machine learning algorithm improved model performance by 28–46%. <b>Citation:</b> Wilford, J. and Roberts, D., 2020. Enhanced barest earth Landsat imagery for soil and lithological modelling. 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.