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  • This resource includes bathymetry data acquired during the Southern Depths of the Great Barrier Reef survey using Kongsberg EM302 and EM710 multibeam sonar systems. The Southern Great Barrier Reef Shelf Bathymetry survey (FK201122/GA4867); also known as Ice Age Geology of the Great Barrier Reef survey; was led by Queensland University of Technology aboard the Schmidt Ocean Institute's research vessel Falkor from the 22nd of November to the 21st of December 2020. The primary objective of the expedition was to explore ancient undersea features that formed during the last Ice Age, when sea level was around 125 m lower than it is today. While once an exposed part of the Australian coast, these shelf areas were submerged as Earth’s glaciers and ice sheets melted and sea level rose, flooding Australia’s continental shelf. Another objective was to find the southern extent of an older limestone platform that may represent the approximately 20 million-year-old base upon which the present Great Barrier Reef has grown. This V1 dataset contains two 64m resolution 32-bit floating point geotiff files of the Southern Great Barrier Reef Shelf Bathymetry survey area, derived from the processed EM302 and EM710 bathymetry data, using CARIS HIPS and SIPS software. This dataset is not to be used for navigational purposes. This dataset is published with the permission of the CEO, Geoscience Australia.

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    Total magnetic intensity (TMI) data measures variations in the intensity of the Earth's magnetic field caused by the contrasting content of rock-forming minerals in the Earth crust. Magnetic anomalies can be either positive (field stronger than normal) or negative (field weaker) depending on the susceptibility of the rock. The data are processed via standard methods to ensure the response recorded is that due only to the rocks in the ground. The results produce datasets that can be interpreted to reveal the geological structure of the sub-surface. The processed data is checked for quality by GA geophysicists to ensure that the final data released by GA are fit-for-purpose. This Magnetic Anomaly Map of Australia, Seventh Edition, 2019 TMI Greyscale image is a greyscale image of the TMI grid of the Magnetic Anomaly Map of Australia, Seventh Edition, 2019. The 2019 Total magnetic Intensity (TMI) grid of Australia has a grid cell size of ~3 seconds of arc (approximately 80 m). This grid only includes airborne-derived TMI data for onshore and near-offshore continental areas. Since the sixth edition was released in 2015, data from 234 new surveys have been added to the database, acquired mainly by the State and Territory Geological Surveys. The new grid was derived from a re-levelling of the national magnetic grid database. The survey grids were levelled to each other, and to the Australia Wide Airborne Geophysical Survey (AWAGS), which serves as a baseline to constrain long wavelengths in the final grid. It is estimated that 33 500 000 line-kilometres of survey data were acquired to produce the 2019 grid data, about 2 000 000 line-kilometres more than for the previous edition. The grid used to produce this greyscale image has a cell size of 0.00083 degrees (approximately 80m). This greyscale image shows the magnetic response of subsurface features with contrasting magnetic susceptibilities. The image can also be used to locate structural features such as dykes.

  • <p>In this study, a total of 53 surface outcrop samples were analysed for both inorganic and organic whole-rock geochemistry as part of Exploring for the Future (EFTF) program, a government initiative undertaken by the Australian Government to boost investment in resource exploration and development in northern Australia. The samples were collected during two EFTF funded field seasons conducted in May 2017 (18 samples, GA job number 33004) and May 2018 (35 samples, GA job number 33228). <p>This data release contains the results of elemental analyses including X-Ray Fluorescence (XRF), Inductively Coupled Plasma- Mass Spectrometry (ICP-MS), iron titration (FeO), Loss-On-Ignition (LOI) and Rock-Eval pyrolysis on 53 outcrop samples collected across two seasons of fieldwork in the South Nicholson region. This data release are provided to facilitate establishment of important baseline assessments and whole rock characterisation of regional sedimentary rocks for insight into the resource prospectivity of northern Australian basins. These data was generated at the Geochemistry Laboratories at Geoscience Australia as part of the Exploring for the Future program

  • A framework is presented for the probabilistic modelling of non-stationary coastal storm event sequences, and is applied to a study site on the East Australian Coast. Storm waves at this site are found to exhibit non-stationarities related to ENSO and seasonality. The impact of ENSO is most prominent for storm wave direction, long term MSL and the rate of storms, while seasonal non-stationarity is more ubiquitous, affecting the latter variables as well as storm wave height, duration, period and surge. The probabilistic framework herein separates the modelling of ENSO and seasonal non-stationarity in the storm wave properties from the modelling of their marginal distributions, using copulas. This separation enables non-stationarities to be straightforwardly modelled in all storm wave variables, irrespective of whether parametric or non-parametric techniques are used to model their marginal distributions. Storm wave direction and steepness are modelled with non-parametric distributions whereas storm wave height, duration and surge are modelled parametrically using extreme-value mixture distributions. The advantage of the mixture distributions, compared with the standard extreme value distribution for peaks-over-threshold data (Generalized Pareto), is that the statistical threshold becomes a model parameter instead of being fixed, and so uncertainties in the threshold can be straightforwardly integrated into the analysis. Uncertainties in the model predictions are quantified using a mixture of parametric percentile bootstrap and Bayesian techniques. Percentile bootstrap confidence intervals are shown to non-conservatively underestimate uncertainties in the extremes (e.g. 1% annual exceedance probability wave heights), both in an idealized setting and in our application. The Bayesian approach is applied to the extreme value models to remedy this shortcoming. The modelling framework is applicable to any site where multivariate storm wave properties and timings are affected by seasonal, climatic and long-term non-stationarities. This paper is published in Coastal Engineering, see

  • The Buddycurrawa Volcanics (BV, Benmara Group) are a sequence of trachyte lavas and interleaved shallow-marine siliciclastic rocks, exposed in the Benmara region, northwestern Mount Drummond 1:250 000 map sheet, Northern Territory. Previous information, including resource potential, on the BV was limited, and stratigraphic correlation with other regional volcanic units was speculative. Our new geochronology data establish the extrusion age of the BV as late Paleoproterozoic, constrained by a maximum age of ca. 1662 Ma (SHRIMP U-Pb zircon) and a minimum age of ca 1631 Ma (in situ laser Rb-Sr on glauconite within vesicles). The BV are, therefore, temporally equivalent to numerous ash fall tuffs reported throughout regional highly prospective late Paleoproterozoic successions. The BV also host vertical siliceous pipes, representing ‘white smokers’—peripheral low-temperature equivalents of black smokers—suggestive of a regional shallow-marine hydrothermal circulatory system and potential for associated base metal mineral systems. The BV are pervasively potassically altered. Laser Rb-Sr dating on matrix secondary microcline returns ages ca. 1612–1323 Ma, reflecting timing of fluid flow responsible for at least some of the potassic alteration. These are broadly consistent with similar estimates of episodes of regional fluid flow and base metal mineralisation and/or remobilisation in the Mount Isa Province. <b>Citation:</b> Carson, C.J., Kositcin, N., Farkas, J., Champion, D.C., Whelan, J., Redaa, A., Gilbert. S., Henson, P.A., Maas, R., Williams, B. and Doublier, M.P., 2020. The late Paleoproterozoic Buddycurrawa Volcanics, South Nicholson region. 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.

  • Geoscience Australia is the nation’s trusted provider of independent groundwater science and advice. We support the fair sharing of Australia’s water resources for a strong economy, resilient communities and cultures, and to protect environmental assets. We aspire to identify the location, quantity and quality of Australia’s groundwater resources to support responsible water management.

  • <p>A geochemical study was conducted to establish oil-oil correlations and evaluate potential source rocks within the latest Devonian–earliest Carboniferous succession of the onshore Canning Basin, Western Australia. Aromatic hydrocarbons, together with the routinely used saturated biomarker ratios and stable carbon isotopes, demonstrate that the recently discovered Ungani oilfield located on the southern margin of the Fitzroy Trough are similar, but not identical, to the early Carboniferous Larapintine 4 (L4) oil family present to the north of the Fitzroy Trough on the Lennard Shelf. The L4 oil family has been correlated to a lower Carboniferous (Tournaisian) source rock core sample from the Laurel Formation at Blackstone-1 although its bulk geochemical properties signify that it could generate substantially more gas than liquid hydrocarbons. <p>The Ungani oils can be distinguished from the L4 oils by their higher concentrations of paleorenieratane and isorenieratane, coupled with more depleted δ13C values for n-alkanes, pristane and phytane compared with other components. Hopane isomerisation ratios show distinct grouping of the two oil families that reflect both source and maturity variations. The oil from Wattle-1 ST1 on the Lennard Shelf also has an unusual composition, exhibiting some molecular and isotopic features similar to both the L4 and Ungani oils. Source rocks for the Ungani and Wattle-1 ST1 oils are unknown since their geochemical signature does not match that of the Tournaisian Laurel Formation or the Middle−Upper (Givetian–Frasnian) Devonian Gogo Formation which sourced the Devonian-reservoired Larapintine 3 oils at Blina and Janpam North-1. It is postulated that such potential oil-prone source rocks could occur within the Famennian–Tournaisian succession.

  • <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

  • <b>BACKGROUND</b> <p> <p>The United States Geological Survey's (USGS) Landsat satellite program has been capturing images of the Australian continent for more than 30 years. This data is highly useful for land and coastal mapping studies. <p>In particular, the light reflected from the Earth’s surface (surface reflectance) is important for monitoring environmental resources – such as agricultural production and mining activities – over time. <p>We need to make accurate comparisons of imagery acquired at different times, seasons and geographic locations. However, inconsistencies can arise due to variations in atmospheric conditions, sun position, sensor view angle, surface slope and surface aspect. These need to be reduced or removed to ensure the data is consistent and can be compared over time. <p>&nbsp</p> <b>WHAT THIS PRODUCT OFFERS</b> <p> <p>GA Landsat 7 ETM+ Analysis Ready Data Collection 3 takes Landsat 7 Enhanced Thematic Mapper (ETM+) imagery captured over the Australian continent and corrects for inconsistencies across land and coastal fringes. The result is accurate and standardised surface reflectance data, which is instrumental in identifying and quantifying environmental change. <p> <p>The ETM+ instrument is a fixed ‘whisk broom’, eight-band, multispectral scanning radiometer capable of providing high-resolution imaging information of the Earth’s surface. It is an enhanced version of the Thematic Mapper (TM) sensor. <p> <p>This product is a single, cohesive Analysis Ready Data (ARD) package, which allows you to analyse surface reflectance data as is, without the need to apply additional corrections. <p> <p>It contains three sub-products that provide corrections or attribution information: <p> <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;1) GA Landsat 7 ETM+ NBAR Collection 3 <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;2) GA Landsat 7 ETM+ NBART Collection 3 <p>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;3) GA Landsat 7 ETM+ OA Collection 3 <p> <p>The resolution is a 30 m grid based on the USGS Landsat Collection 1 archive.