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  • Preamble -- The 'National Geochemical Survey of Australia: The Geochemical Atlas of Australia' was published in July 2011 along with a digital copy of the NGSA geochemical dataset (doi: 10.11636/Record.2011.020). The NGSA project is described here: www.ga.gov.au/ngsa. The present dataset contains additional geochemical data obtained on NGSA samples: the Plutonium Isotopes Dataset. Abstract -- Seventy three fine-fraction (<75 um) Top Outlet Sediment (TOS, 0 – 10 cm depth) NGSA samples from Queensland were analysed for the plutonium (Pu) isotopes 238Pu and 239+240Pu (unresolved 239Pu and 240Pu) to determine: (1) if Pu is detectable in the Australian environment; and (2) what the levels and ranges of Pu retention in selected Queensland catchment soils are. Radiochemical analyses were performed by alpha spectrometry at the radioanalytical laboratories of Radiation and Nuclear Sciences, Department of Health, Queensland, and at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Victoria. The method yielded a 239+240Pu trace-level detection limit of 0.04 mBq/g (equivalent to 10.4 fg/kg or 0.0056 net counts per minute) with a relative standard deviation (RSD) of 15.1%. The average tracer recovery was 69% (RSD 25%) over a 3-day count. Total analytical uncertainty ranged from 19% to 90% at close to detection limits. Field duplicate repeatability for 239+240Pu activity concentration ranged from 18% to 45%, which in part at least reflects the inherent heterogeneity of soil/sediments containing refractory particles exhibiting variation in Pu activity concentrations. Analytical duplicate repeatability for 239+240Pu activity concentration ranged from 10% to 23%, with the mean activity concentration and error of the replicates reported with propagation of errors. The results show a wide range of 239+240Pu activity concentration in the fine TOS NGSA samples across Queensland (N = 73): 239+240Pu: Min = <0.04 mBq/g; Med ± MAD (median absolute deviation) = 0.09 ± 0.07 mBq/g; Mean ± SD = 0.29 ± 0.72 mBq/g; 95th percentile = 1.53 mBq/g; Max = 4.88 mBq/g. In comparison the world average background is estimated at 0.2 mBq/g. Analytical results for 39% of samples were below detection. Six samples with 239+240Pu > 0.18 mBq/g (70th percentile) were also analysed for 238Pu by the same alpha spectrometry method. Results ranged from 0.04 to 0.1 mBq/g (N = 6). The complete dataset is available to download as a comma separated values (CSV) file from Geoscience Australia's website (http://pid.geoscience.gov.au/dataset/ga/144101).

  • These shapefiles were prepared by the Geological Survey of NSW from the original 1993 Bureau of Mineral Resources ESRI coverages. The data is also available from the Geological Survey of NSW website.

  • Geoscience Australia (GA), the Australian Institute of Marine Science (AIMS) and the Department of Environment and Natural Resources within the Northern Territory Government (DENR) undertook collaborative seabed mapping surveys (GA0351/SOL6187, GA4452/SOL6432 and combined GA0361 & GA0362) in the Darwin-Bynoe Harbour region between 2015 and 2018. This seabed mapping project forms a core component of a four-year collaborative research program between DENR, GA and AIMS, which was funded by the INPEX-operated Ichthys LNG Project to DENR, with co-investment by GA and AIMS. The purpose of the program is to improve knowledge of the marine environments in the Darwin and Bynoe Harbour regions through the collation and acquisition of baseline data that enable the creation of habitat maps to better inform marine resource management decisions. Mapping and sampling in the survey area utilised multibeam echosounders, sub-bottom profilers, underwater cameras and grab samplers. In total, this data package extends over an area of 1978 km2, including 1754 km2 mapped using multibeam echosounders, during four marine surveys over 247 days. The baseline environmental data acquired in this program provides new insights into the marine environments of the Greater Darwin and Bynoe Harbour region, will inform future environmental assessments in the region and help build our knowledge of seabed features and processes in tropical northern Australia.

  • On behalf of Australia, the Australian Transport Safety Bureau (ATSB) is leading search operations for missing Malaysian airlines flight MH370 in the Southern Indian Ocean. Geoscience Australia provided advice, expertise and support to the ATSB to facilitate bathymetric surveys, which were undertaken to provide a detailed map of the sea floor topography to aid navigation during the underwater search. Bathymetric data was acquired by multibeam sonar mounted on the hull of multiple vessels (GA survey reference: GA-4421, GA-4422 & GA-4430). Bathymetric surveys were conducted from June 2014 to February 2017, collecting over 710,000 square kilometres of data in the search area and along transit lines (to and from the search area). This dataset allows exploration of the seafloor topography through an optimal resolution compilation of tiles across the search and transit areas of the Southern Indian Ocean. The dataset is overlain on a hillshade created from the Optimal resolution bathymetry data. The hillshade was created with the parameters of point illumination azimuth at 45 degrees and altitude of 45 degrees.

  • In 2008, the Ord Irrigation Cooperative commissioned an airborne electromagnetics (AEM) survey of the ORIA Stage 1 and 2 areas to identify, quantify and understand any potential salinity risks in the current Ord irrigation area and the parts of the catchment that have been identified as potential future irrigation sites or potentially impacted by future irrigation. The project has been funded by the Australian and Western Australian governments through the National Action Plan for Salinity and Water Quality. Geoscience Australia and CSIRO were contracted to carry out the analysis and interpretation of the AEM dataset, and produce customised interpretation products. Some of the more specific questions it was hoped to address included: - Are we at risk of salinity in the Ord Catchment? - If so what areas are at the greatest risk? - Where can we target management to reduce this risk? - How can we plan future development to minimise salinity risk and maximise longevity of projects? The areas surveyed include the current Stage 1 Ord Irrigation Area, Stage 2 Irrigation Area (including Weaber and Knox Plains and Carlton Hill - Parry's Lagoon Conservation Area. The inclusion of undeveloped land in this survey is because the technology provides the opportunity to ensure any future irrigation development is guided by the best available information on soil type, aquifer quality and location and salinity risk. The information generated by this project will be publicly available and can be used for such things as: - Identifying leaky areas in the landscape that may require more concentrated management or can be designated for more suitable land use; - Where salt is stored in the landscape and at what depth, and where in the landscape it may influence plant growth; - Provide new constraints on the connectivity of aquifer systems in 3D across the ORIA and enable the construction of more realistic hydrogeological models to improve surface and groundwater management.

  • Airborne Electromagnetic data are being acquired by Geoscience Australia in areas considered to have potential for uranium or thorium mineralisation under the Australian Government's Onshore Energy Security Program (OESP). The surveys have been managed and interpreted by Geoscience Australia's Airborne Electromagnetic Acquisition and Interpretation project. In contrast to industry style deposit scale investigations, these surveys are designed to reveal new geological information at regional scale. The Frome Embayment AEM survey was acquired using the TEMPEST<sup>TM</sup> AEM system by Fugro Airborne Surveys under contract to Geoscience Australia. The survey covers a total of 32 300 line km and an area of 95 450 km<sup>2</sup>, the largest AEM survey by area ever flown in Australia. Phase-1 data, that is, contractor quality-controlled and quality-assessed data for the Frome survey, were released during March 2011. Phase-2 data, that is Geoscience Australia layered earth inversion (GA-LEI) data and derived products to 400m were released in July 2011. This data package contains GA-LEI data and derived products to 200m. Data and products described in this report are available from the GA AEM website.

  • Airborne Electromagnetic data are being acquired by Geoscience Australia in areas considered to have potential for uranium or thorium mineralisation under the Australian Government's Onshore Energy Security Program (OESP). The surveys have been managed and interpreted by Geoscience Australia's Airborne Electromagnetic Acquisition and Interpretation project. In contrast to industry style deposit scale investigations, these surveys are designed to reveal new geological information at regional scale. The Pine Creek airborne electromagnetic survey comprised of three survey areas Woolner Granite, Rum Jungle and Kombolgie. Tempest data were acquired for Woolner Granite and Rum Jungle survey areas and are included in this report. Woolner Granite and Rum Jungle survey areas cover a total of 21 100 line km and an area of 43 200 km2. Phase-1 data, that is, contractor quality-controlled and quality-assessed data for Woolner Granite, Rum Jungle and Kombolgie, were released during 2009. Phase-2 data, that is Geoscience Australia layered earth inversion (GA-LEI) data and derived products for Woolner Granite and Rum Jungle, are included in this data release. The data and products described in this report are contained on the accompanying DVD. The Kombolgie survey data were acquired with VTEM. The VTEM Kombolgie inversion data and report will be included in a separate data release. The main products from the AEM surveys are conductivity depth slices and sections, conductance grids and an AEM Depth of Investigation grid. The data is provided in formats which can be viewed on most computers systems. They include, JPEG (.jpg) with associated world files for easy use in geographic information system (GIS) packages, ER Mapper grids (.ers), ESRI shape files (.shp) of the flight path, and point-located ASCII data with relevant metadata for derived products.

  • These data are one of a set of 13 that captures a consistent horizon and fault interpretation of approximately 35 000 km of regional, mostly deep, seismic reflection data recorded by AGSO along the north and northwestern continental margins of Australia between 1990 and 1994.

  • These data are one of a set of 13 that captures a consistent horizon and fault interpretation of approximately 35 000 km of regional, mostly deep, seismic reflection data recorded by AGSO along the north and northwestern continental margins of Australia between 1990 and 1994.

  • These data are one of a set of 13 that captures a consistent horizon and fault interpretation of approximately 35 000 km of regional, mostly deep, seismic reflection data recorded by AGSO along the north and northwestern continental margins of Australia between 1990 and 1994.