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  • We collected 38 groundwater and two surface water samples in the semi-arid Lake Woods region of the Northern Territory to better understand the hydrogeochemistry of this system, which straddles the Wiso, Tennant Creek and Georgina geological regions. Lake Woods is presently a losing waterbody feeding the underlying groundwater system. The main aquifers comprise mainly carbonate (limestone and dolostone), siliciclastic (sandstone and siltstone) and evaporitic units. The water composition was determined in terms of bulk properties (pH, electrical conductivity, temperature, dissolved oxygen, redox potential), 40 major, minor and trace elements as well as six isotopes (δ18Owater, δ2Hwater, δ13CDIC, δ34SSO4=, δ18OSO4=, 87Sr/86Sr). The groundwater is recharged through infiltration in the catchment from monsoonal rainfall (annual average rainfall ~600 mm) and runoff. It evolves geochemically mainly through evapotranspiration and water–mineral interaction (dissolution of carbonates, silicates, and to a lesser extent sulfates). The two surface waters (one from the main creek feeding the lake, the other from the lake itself) are extraordinarily enriched in 18O and 2H isotopes (δ18O of +10.9 and +16.4 ‰ VSMOW, and δ2H of +41 and +93 ‰ VSMOW, respectively), which is interpreted to reflect evaporation during the dry season (annual average evaporation ~3000 mm) under low humidity conditions (annual average relative humidity ~40 %). This interpretation is supported by modelling results. The potassium (K) relative enrichment (K/Cl mass ratio over 50 times that of sea water) is similar to that observed in salt-lake systems worldwide that are prospective for potash resources. Potassium enrichment is believed to derive partly from dust during atmospheric transport/deposition, but mostly from weathering of K-silicates in the aquifer materials (and possibly underlying formations). Further studies of Australian salt-lake systems are required to reach evidence-based conclusions on their mineral potential for potash, lithium, boron and other low-temperature mineral system commodities such as uranium. <b>Citation:</b> P. de Caritat, E. N. Bastrakov, S. Jaireth, P. M. English, J. D. A. Clarke, T. P. Mernagh, A. S. Wygralak, H. E. Dulfer & J. Trafford (2019) Groundwater geochemistry, hydrogeology and potash mineral potential of the Lake Woods region, Northern Territory, Australia, <i>Australian Journal of Earth Sciences</i>, 66:3, 411-430, DOI: 10.1080/08120099.2018.1543208

  • Geochemical surveys deliver fundamental data, information and knowledge about the concentration and spatial distribution of chemical elements, isotopes and compounds in the natural environment. Typically near-surface sampling media, such as soil, sediment, outcropping rocks and stream or groundwater, are used. The application of such datasets to fields such as mineral exploration, environmental management, and geomedicine has been widely documented. In this presentation I reflect on a sabbatical experience with the Australian Federal Police (AFP) in 2017-2018 that allowed me to extend the interpretation of geochemical survey data beyond these established applications. In particular, with my collaborators we explore ways in which geochemical survey data and maps can be used to indicate the provenance of an evidentiary sample collected at a crime scene or obtained for instance from items belonging to a suspect intercepted at border entry. Because soils are extremely diverse mineralogically, geochemically and biologically, it should theoretically be possible to exclude very large swathes of territory (>90%) from further provenancing investigation using soil data. In a collaboration between Geoscience Australia (GA), the AFP and the University of Canberra (UC), a recent geochemical survey of the urban/suburban Canberra region in southeastern Australia is being used as a testbed for developing different approaches to forensic applications of geochemical surveys. A predictive soil provenancing method at the national scale was also developed and tested for application where no actual detailed, fit-for-purpose geochemical survey data exist. Over the next few years, GA, AFP and UC are collaborating with Flinders University to add biome data from soil and soil-derived dust to further improve the provenancing technique. This Abstract was presented at the 2021 Goldschmidt Conference (https://conf.goldschmidt.info/goldschmidt/2021/meetingapp.cgi)

  • GA publication: Flyer AEIP, ELVIS, EM-LINK 2021

  • AusAEM (WA) 2020-21, Earaheedy & Desert Strip Airborne Electromagnetic Survey The accompanying data package, titled “AusAEM (WA) 2020-21,Earaheedy & Desert Strip Airborne Electromagnetic Survey Blocks: TEMPEST® airborne electromagnetic data and GALEI conductivity estimates”, was released on 25 March 2021 by Geoscience Australia (GA) and the Geological Survey of Western Australia. The data represents the first phase of the AusAEM2020 (WA) survey flown with a fixed-wing aircraft by CGG Aviation (Australia) Pty. Ltd. under contract to Geoscience Australia, using the TEMPEST® airborne electromagnetic system. The survey was flown at a 20-kilometre nominal line spacing over the most eastern part of the state and down to the southern coast of Western Australia. The total area encompasses close to 32,680 line kilometres of newly acquired airborne electromagnetic geophysical data. CGG also processed the data. This package contains 14,279 line kilometres of the survey data, which have been quality-controlled, processed and inverted. The Earaheedy Block entailed approximately 6,407 line kilometres and the Desert Strip 7,870 line kilometres. The remaining data will be released as a separate package. Geoscience Australia and Western Australia (Department of Mines, Industry Regulation and Safety) commissioned the AusAEM 2020 survey as part of the national airborne electromagnetic acquisition program, to complete 20km line separation AEM coverage over WA. The program is designed to deliver freely available pre-competitive geophysical data to assist in the investigation and discovery of potential mineral, energy and groundwater resources within Australia. Funding for the survey came from the Western Australian government’s Exploration Incentive Scheme. GA managed the survey data acquisition, processing, contracts, quality control of the survey and generated the inversion products included in the data package. The data release package contains 1. A data release package summary PDF document. 2. The survey logistics and processing report and TEMPEST® system specification files 3. ESRI shapefiles for the regional and infill flight lines 4. Final processed point located line data in ASEG-GDF2 format 5. Conductivity estimates generated by CGG’s EMFlow conductivity-depth transform -point located line data output from the inversion in ASEG-GDF2 format -graphical (PDF) multiplot conductivity sections and profiles for each flight line -Grids generated from CGG's inversion conductivity-depth transform in ER Mapper® format (layer conductivities) 6. Conductivity estimates generated by Geoscience Australia's inversion -point located line data output from the inversion in ASEG-GDF2 format -graphical (PDF) multiplot conductivity sections and profiles for each flight line -georeferenced (PNG) conductivity sections (suitable for pseudo-3D display in a 2D GIS) -GoCAD™ S-Grid 3D objects (suitable for various 3D packages)

  • This resource includes seabed backscatter data for South-west Corner Marine Park collected by Geoscience Australia during the periods 9 – 12 March 2020 and 27 January – 16 February 2021 on the charter vessel Santosha. The survey was undertaken as a collaborative project with the University of Western Australia, the University of Tasmania and the Australian Centre for Field Robotics (University of Sydney) and funded through the National Environmental Science Program Marine Biodiversity Hub, with co-investment by all partners and the Director of National Parks. The purpose of the project was to build baseline information for benthic habitats on the continental shelf in the marine park that will support ongoing environmental monitoring within the South-west Marine Park Network as part of the 10-year management plan (2018-2028). Data acquisition for the project included multibeam bathymetry and backscatter for an area covering 330 km^2 offshore from Cape Naturaliste to Cape Leeuwin coast, with underwater imagery of benthic communities and demersal fish collected by University of Western Australia on separate field deployments. This backscatter dataset contains a 4 m resolution 32-bit geotiff file of the survey area produced from the processed Kongsberg EM2040C multibeam sonar system data using the CMST-GA MB Process v15.04.04.0 (.64) toolbox software co-developed by the Centre for Marine Science and Technology at Curtin University and Geoscience Australia. For further information see: Giraldo-Ospina, A. et al., 2021. South-west Corner Marine Park Post Survey Report. Report to the National Environmental Science Program, Marine Biodiversity Hub.

  • The annual offshore petroleum exploration acreage release is part of the government’s strategy to promote offshore oil and gas exploration. Each year, the government invites companies to bid for the opportunity to invest in oil and gas exploration in Australian waters. The 2020 acreage release consists of 42 areas offshore of the Northern Territory, Western Australia, Victoria and the Ashmore and Cartier Islands.

  • This dataset provides the locations and status, as at 30 June 2020, of Australian operating mines, mines under development, mines on care and maintenance and resource deposits associated with critical minerals. Developing mines are deposits where the project has a positive feasibility study, development has commenced or all approvals have been received. Mines under care and maintenance and resource deposits are based on known resource estimations and may produce critical minerals in the future.

  • These videos are recordings of online secondary teacher professional learning sessions, delivered by Geoscience Australia’s Education Team. “Can I Fall Down the Cracks?” Plate Tectonic Misconceptions Part 1 This session focused on common misconceptions that are encountered when teaching plate tectonics. The student misconceptions addressed are: 1. We can’t see the tectonic plates (starting at 5:35) 2. The mantle is made of liquid rock (starting at 11:25) 3. The plates move by convection in the mantle (starting at 17:35) 4. When plates collide one always goes under the other (starting at 22:15) 57 minutes total duration, with Q&A with an expert scientist starting at 34 minutes. “Can I Fall Down the Cracks?” Plate Tectonic Misconceptions Part 2 This session focused on common misconceptions that are encountered when teaching hazards associated with plate tectonics. The student misconceptions addressed are: 1. Earthquakes are measured using the Richter scale (starting at 3:15) 2. The magnitude of an earthquake depends on how far away it is (starting at 7:20) 3. Earthquakes can be predicted (starting at 10:52) This section includes a description of Raspberry Shake equipment: low cost earthquake monitoring for the classroom 4. There are no volcanoes in Australia (starting at 18:25) 5. You can surf a tsunami (starting at 24:17) 51 minutes total duration, with Q&A with an expert scientist starting at 37 minutes.

  • A two part Indigenous-led and produced Aboriginal cultural heritage awareness training video for Geoscience Australia staff. The video explores a number of topics from the perspective of Traditional Owners and Custodians. Topics covered include: What is Country, Lore and Kinship; the importance of listening, connecting to Country and the transference of knowledge; Aboriginal cultural heritage legislation and policy in Australia, native title and cultural heritage; the impact of past policies; and, working towards best practice. The video complements Geoscience Australia's Land Access and Cultural Heritage Policy, Procedures and Best Practice Standards.

  • National meteorological and hydrological services (NMHSs) provide severe weather warning information to inform decision-making by emergency management (EM) services and to allow communities to take defensive and mitigation action prior to and during severe weather events. Globally, warning information issued by NMHSs varies widely from solely hazard-based to impact-based forecasting encompassing the exposure and vulnerability of communities to severe weather. The most advanced of these systems explicitly and quantitatively model the impacts of hazards on sectors of interest. Incorporating impact information into severe weather warnings contextualises and personalises the warning information, increasing the likelihood that individuals and communities will take preparatory action. This paper reviews a selection of current efforts towards severe weather warnings and impact forecasting capabilities globally and highlights uncertainties that currently limit forecasts and modelling of multi-hazard events.