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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

  • Geoscience Australia’s Exploring for the Future program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to a low emissions economy, strong resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The Exploring for the Future program, which commenced in 2016, is an eight-year, $225m investment by the Australian Government. The Darling-Curnamona-Delamerian (DCD) 2D reflection seismic survey was acquired during May to August 2022 in the Delamerian Orogen, the Murray-Darling basin, the Curnamona Province, and the upper Darling River floodplain regions in South Australia, Victoria and New South Wales. This project is a collaboration between Geoscience Australia (GA), the Geological Survey of South Australia (GSSA), the Geological Survey of Victoria (GSV) and the Geological Survey of New South Wales (GSNSW) and was funded by the Australian Government’s Exploring for the Future (EFTF) program. The overall objective of the EFTF Darling-Curnamona-Delamerian project is to improve the understanding of mineral and groundwater resources of the Curnamona Province and Delamerian Orogen and overlying basin systems through acquisition and interpretation of new pre-competitive geoscience data sets. The total length of acquisition was 1256 km distributed over five deep crustal 2D reflection seismic lines 22GA-DL1 (446 km), 22GA-DL2 (249 km), 22GA-CD1 (287 km), 22GA-CD2 (178 km), 22GA-CD3 (39.5 km) to image deep crustal structures, and a high-resolution 2D reflection seismic line 22GA-UDF (56 km) to explore groundwater resources. The DL lines provide coverage of fundamental geophysical data over the Flinders Range, the Delamerian Province and the Murray-Darling basin region in eastern South Australia and Victoria. The CD lines extend through the Curnamona Province and into the Darling Basin. The UDF line will assist with refining the hydrogeological model, understanding groundwater dynamics, and locating areas better suited to groundwater bores for better quality groundwater in the upper Darling River floodplain area. The data processing was performed by a contractor under the supervision of Geoscience Australia. The five deep crustal lines (22GA-DL1,DL2,CD1,CD2,CD3) were processed with record lengths of 20 and 8 seconds, while the shallow high-resolution line (22GA-UDF) was processed at a 4 second length. This processing yielded DMO Stack, Post-Stack Time Migration, and Pre-Stack Time Migration products. <strong>Raw shot gathers and processed gathers for this survey are available on request from clientservices@ga.gov.au - Quote eCat# 147423</strong>

  • The Historical Bushfire Boundaries service represents the aggregation of jurisdictional supplied burnt areas polygons stemming from the early 1900's through to 2022 (excluding the Northern Territory). The burnt area data represents curated jurisdictional owned polygons of both bushfires and prescribed (planned) burns. To ensure the dataset adhered to the nationally approved and agreed data dictionary for fire history Geoscience Australia had to modify some of the attributes presented. The information provided within this service is reflective only of data supplied by participating authoritative agencies and may or may not represent all fire history within a state.

  • 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)

  • Older unreinforced masonry (URM) buildings have been found to perform poorly in historical Australian earthquakes. Where these building are present in pedestrian precincts, they represent a significant risk to people and communities. Some towns and cities have a significant proportion of this type of building within business districts and Perth CBD is an example having 48% by number of URM construction ranging from pre-Federation to early-to-mid twentieth century in age. Further, these buildings are often of significant heritage value providing a sense of place to residents and contribute to visitor related business revenue. These factors all come to play in the town of York which is also in an area of elevated earthquake hazard. There is a need for information inform strategies and decision making around reducing the risk they represent. This project has had a focus on York and was designed as a three-year collaboration between researchers, industry and local stakeholders to improve the understanding of the vulnerability of older unreinforced masonry (URM) buildings. The building types considered are of the types found in York and other larger communities and the project has included methods of retrofit that can enhance the resilience of these buildings to earthquake hazard. It has further included the promotion of expertise with building design professionals and in the construction industry to undertake this work through a demonstration projects. Specifically, the project has been a collaboration between the Shire of York, the Department of Fire and Emergency Services, the University of Adelaide and Geoscience Australia. While not a direct project partner, the Department of Planning Lands and Heritage (DPLH) has also been a key stakeholder that has sought to facilitate the application for grant funding for the mitigation activity to be studied as part of this project.

  • <div>This report contains information about the operation of Geoscience Australia’s ten permanent geomagnetic observatories, repeat stations and other relevant information covering the period from 2017 to 2021.</div><div>Information regarding the activities and services of Geoscience Australia’s Geomagnetism program, distribution of geomagnetic data, geomagnetic instrumentation and data processing procedures is also provided.</div><div><br></div>

  • <div>This report presents the results from detailed palynological analyses of both newly processed samples and re-analysis of existing slides across the upper Permian to Lower Triassic section from the following wells across the southern Bonaparte Basin: Tern 3, Tern 5, Ascalon 1A, Blacktip P1, Blacktip 2, Petrel 1A, Petrel 4, Petrel 5, Prometheus 1, Rubicon 1, Torrens 1. This palynological zonal work is supplemented with palynofacies analyses in a subset of wells. In addition to these new analyses, a review of the existing palynological data from open file palynological reports (in company well completion reports) was undertaken for both the immediately under- and overlying late Permian and earliest Triassic intervals in the newly sampled wells and offset wells of the Tern and Petrel gas fields,&nbsp;including the following wells: Petrel 2, Petrel 3, Petrel 6, Tern 1, Tern 2, Tern 4.</div>

  • Geoscience Australia’s Exploring for the Future program (EFTF) provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. The Australian Passive Seismic Array Project (AusArray) program developed from a long history of passive seismic imaging in Australia involving many contributors. Building on this history, the Australian Government (EFTF), academia and state governments have united around AusArray. The objective is a standardised and quality controlled national passive seismic data coverage and an updatable national seismic velocity model framework that can be used as a background for higher-resolution studies. The AusArray passive seismic data are supplemented with active seismic data that can provide P-wave and S-wave velocity information for the near surface down to about 50 m depth. This near-surface velocity data will provide constraints for some AusArray passive seismic data modelling to obtain more reliable depth models. This document details the active seismic data acquisition using TROMINO® three-axis broadband seismometers using a wireless trigger and hammer source. Equipment packing, field operations, data extraction and preparation, and Multichannel Analysis of Surface Waves (MASW) modelling are described.

  • <div>The South Nicholson National Drilling Initiative (NDI) Carrara 1 stratigraphic drill hole was completed in late 2020, as a collaboration between Geoscience Australia, the Northern Territory Geological Survey (NTGS), and the MinEx CRC. The drilling aimed to gather new subsurface data on the potential mineral and energy resources in the newly identified Carrara Sub-basin. NDI Carrara 1 is located in the eastern Northern Territory, on the western flanks of the Carrara Sub-basin on the South Nicholson Seismic line, reaching a total depth of 1751 m, intersecting ca. 630 m of Cambrian Georgina Basin overlying ca. 1100 m of Proterozoic carbonates, black shales and minor siliciclastics (https://portal.ga.gov.au/bhcr/minerals/648482).</div><div>&nbsp;</div><div>Following a public data release of the borehole completion report, CSIRO was contracted by Geoscience Australia (GA) under the Exploring for the Future program to analyse samples from NDI Carrara 1 for quantitative bulk and clay fraction analysis. This report presents results for quantitative bulk and clay (<2 µm) fraction analysis by X-ray powder diffraction (XRD) on 32 bulk core samples from the NDI Carrara 1. Samples were prepared and analysed at the CSIRO’s Waite Laboratories in South Australia.</div><div><br></div>

  • <div>Levelling of geochemical data between surveys is a vital step in using datasets together. This code can apply a number of approaches to eliminate inter-laboratory differences from multi-generational and spatially isolated geochemical surveys. This codes allow the use of a variety of levelling methods: re-analysis, single standards, and multiple standards. The methodology and effectiveness of each of these methods are outlined in Main, P.T. and Champion, D.C., 2022. Levelling of multi-generational and spatially isolated geochemical surveys. Journal of Geochemical Exploration.</div>