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  • The GILMORE project is a pilot study designed to test holistic systems approaches to mapping mineral systems and dryland salinity in areas of complex regolith cover. The project is coordinated by the Australian Geological Survey Organisation, and involves over 50 scientists from 14 research organisations. Research partners include: Cooperative Research Centres for Advanced Mineral Exploration Technologies (CRC AMET), Landscape Evolution and Mineral Exploration (CRC LEME), the CRC for Sensor Signal and Information Processing, and the Australian Geodynamics Cooperative Research Centre (AGCRC) Land and Water Sciences Division of Bureau of Rural Sciences (BRS) NSW Department of Land & Water Conservation and the NSW Department of Mineral Resources. Various universities including the Australian National University, University of Canberra, Macquarie University, Monash University, University of Melbourne, and Curtin University of Technology, and Australian National Seismic Imaging Resource (ANSIR). The project area lies on the eastern margin of the Murray-Darling Basin in central-west NSW. The project area was chosen for its overlapping mineral exploration (Au-Cu) and salinity management issues, and the availability of high-resolution geophysical datasets and drillhole materials and datasets made available by the minerals exploration industry. The project has research agreements with the minerals exploration industry, and is collaborating with rural land-management groups, and the Grains Research and Development Corporation. The study area (100 x 150 km), straddles the Gilmore Fault Zone, a major NNW-trending crustal structure that separates the Wagga-Omeo and the Junee-Narromine Volcanic Belts in the Lachlan Fold Belt. The project area includes tributaries of the Lachlan and the Murrumbidgee Rivers, considered to be two of the systems most at risk from rising salinities. This project area was chosen to compare and contrast salt stores and delivery systems in floodplain (in the Lachlan catchment) and incised undulating hill landscapes (Murrumbidgee catchment). The study area is characteristic of other undulating hill landscapes on the basin margins, areas within the main and tributary river valleys, and the footslopes and floodplains of the Murray-Darling Basin itself. Studies of the bedrock geology in the study area reveal a complex architecture. The Gilmore Fault Zone consist of a series of subparallel, west-dipping thrust faults, that juxtapose, from west to east, Cambro-Ordovician meta-sediments and granites of the Wagga Metamorphics, and further to the east, a series of fault-bounded packages comprising volcanics and intrusions, and siliciclastic meta-sediments. Two airborne electromagnetic (AEM) surveys were flown in smaller areas within the two catchments. Large-scale hydrothermal alteration and structural overprinting, particularly in the volcanics, has added to the complexity within the bedrock architecture. The data were originally published on 6 CDs. For ease of download the data have been zipped into the original structure. The contents are as follows: CD1 - An overview of the GILMORE Project with geophysical images, regolith map, drillhole locations, geophysical survey information and maghemite geochemistry. CD2 - Airborne Electromagnetic (AEM) images from the TEMPEST survey with vertical cross-sections linked to the flight lines CD3 - Integrated images of the Airborne Electromagnetic (AEM) data draped over the First Vertical Derivative of the Total Magnetic Intensity CD4 - Integrated images of the Airborne Electromagnetic (AEM) data draped over the First Vertical Derivative of the Total Magnetic Intensity CD5 - High resolution geophysical images from three detailed surveys and data from the Airborne Electromagnetic (AEM) QUESTEM survey CD6 - Geology, geochemistry, downhole data, 3 dimensional models, seismic data, and images linked to downhole point data.

  • A new Geoscience Australia Magnetic Anomaly Grid Database of Australia (MAGDA) has been developed. This database contains publicly available airborne magnetic grid data for on- and near-offshore Australia. Flight-line magnetic data for each survey have been optimally gridded and the grids matched in one inverse process. New composite grids at 250 m and 400 m grid spacing form the basis of the new fourth edition of the Magnetic Anomaly Map of Australia. Aeromagnetic traverses flown around Australia during 1990 and 1994 are used in both quality control of the grids they intersect, and also to constrain grid merging by forcing grid data, where intersected, to the level of the traverse data. Although matching and merging of many grids into a seamless compilation produces a pleasing result, without obvious short-wavelength artefacts, accurate long wavelength components of crustal origin are more difficult to obtain. Errors in the ?tilt? of individual surveys, due either to older instrumentation, errors in processing, or incomplete core-field removal, can lead to large long wavelength errors when hundreds of surveys are combined across thousands of kilometres. Quantification of the accuracy of long-wavelength components is only possible by comparison with independent datasets. A low-pass filtered composite grid of the Australian region has been compared with CHAMP satellite magnetic data, and shows a considerable improvement in the correlation of long wavelength components compared with the previous edition

  • The Broken Hill Managed Aquifer Recharge (BHMAR) project is part of a larger strategic effort aimed at securing Broken Hill's water supply and identifying significant water-saving measures for the Darling River system. The project builds on an earlier scoping study (the Broken Hill Groundwater Assessment (BHGA) Project), which investigated the potential for Broken Hill to source most of its water requirements from groundwater (Lewis et al., 2008). The project is funded by the Australian Government and managed through the Australian Government Department of the Environment, Water, Heritage and the Arts (DEWHA). The project builds on an earlier scoping study (the Broken Hill Groundwater Assessment (BHGA) Project), which investigated the potential for Broken Hill to source most of its water requirements from groundwater (Lewis et al., 2008). The BHGA Project identified a work plan for the BHMAR Project that involves 5 phases: - Phase 1: A risk assessment / AEM technology selection exercise. - Phase 2: Acquire and interpret baseline hydrological and geological data. - Phase 3: Assess feasibility of extraction and storage options for groundwater. - Phase 4: Implement and test preferred groundwater extraction and storage option at a small operational scale. - Phase 5: Construct and operate groundwater extraction/storage option. This interim report summarises the findings of Phase 2 of the BHMAR Project.

  • Data acquired as part of the Kombolgie VTEMTM Airborne Electromagnetic Survey have been inverted using a layered earth inversion algorithm. Interpretation products have been derived from the inversion results. The inversion results and derived products have been released by Geoscience Australia as a digital data package. The survey was funded under the Australian Government's Onshore Energy Security Program, and was managed and interpreted by Geoscience Australia's Airborne Electromagnetic Acquisition and Interpretation Project. The Kombolgie survey area, in the Pine Creek Orogen of the Northern Territory, covered sections of the Cobourg Peninsula, Junction Bay, Alligator River, Milingimbi, Mount Evelyn, Katherine, and Urapunga 1:250 000 map sheets. It covered a total of 8 800 line km and an area of 32 000 km2. The data were acquired under contract by Geotech Airborne Pty. Ltd. using its VTEMTM helicopter-borne electromagnetic system. The inversions were carried out using the GA-LEI layered-earth inversion software developed at Geoscience Australia. Products include the layer conductivities, depth and elevation slices, and sections. The products are in digital form in both point-located and gridded formats. They are available for download from the Geoscience Australia website.

  • The Ord Valley Airborne Electromagnetic (AEM) Interpretation Project (OVAEIP) was a collaborative project between the Ord Irrigation Cooperative (OIC), the Cooperative Research Centre for Landscape, Environments and Mineral Exploration (CRC LEME), Geoscience Australia (GA) and CSIRO, co-funded by both the Australian and Western Australian Governments. The aim was to provide comprehensive spatial information to address specific questions on salinity and groundwater management in the existing Ord Irrigation Area (ORIA) and those earmarked for irrigation expansion. The project included the acquisition of 5936 line km of AEM data using the SKYTEM time domain system, and a Light Ranging and Detection (LiDAR) DEM. This data was used in conjunction with geomorphic mapping, ground and downhole geophysics, drilling information and pre-existing hydrogeological data to produce a suite of derived spatial products including maps of salinity hazard, salt stores, groundwater salinity and lithology. The spatial analysis and interpretation of constrained AEM data and geological mapping have delineated the lithostratigraphy in 3D, including sand and gravel filled palaeochannels, clay and silt distribution, as well as salt stores and groundwater quality. Surface salinity hazard maps were derived using the spatial analysis of LANDSAT-5 TM, AEM, hydrogeological and geomorphic data. The study demonstrated the effectiveness of GIS and geospatial analysis within an integrated approach with products providing a framework for future irrigation development. Outputs include a comprehensive GIS for spatial interrogation and hard-copy atlases for use by stakeholders and local landholders.

  • Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Barr Creek - Gunbower study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Groups assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.

  • Short article describing detection of interpreted unconformity between Coolbro Sandstone and Rudall Complex rocks near the Kintyre uranium deposit, Western Australia

  • The floodplain of the lower Balonne River is in the upper reaches of the Murray Darling Basin. The region has been extensively developed for agriculture, in particular irrigated cotton, and is highly productive. Multidisciplinary investigations to inform land management generated extensive sets of remotely sensed data including Landsat TM, airborne gamma-ray radiometrics, aerial photography, ASTER imagery, and digital elevation models. These datasets provided the basis for regolith and geomorphic mapping. The wealth of data has allowed characterisation of the lower Balonne River system which is typical of many of the dryland rivers of southern Queensland. The geomorphic map of the lower Balonne floodplain has 8 major units based on landform and geomorphic processes. Bedrock consists of the slightly deformed and extensively weathered marine Cretaceous Griman Creek Formation. Coincident with erosion and weathering, Paleogene quartz gravels were deposited and are now extensively cemented and preserved as remnants forming zones of inverted relief. Much of the present landscape consists of a series of juxtaposed depositional units that have infilled an incised valley system. The different depositional units show the palaeo-Balonne River migrating to the west. This is interpreted to be a result of tectonic depression and tilting to the west, causing avulsion and anastomosing of the palaeo-channels. The modern Balonne River system consists of a number of easily recognised segments. In the north, the modern channel is incised as a single channel. To the south the channel opens out onto an anastomosing plain with branching and reconnecting small-scale channels. Source bordering dunes, currently inactive, have also formed along the western and eastern sides of the modern river and are prominent in large dunes in the south along the present Moonie River. Their absence in older landscape elements points to increasing aridity over time in the river system.

  • Presently, groundwater, through direct extraction (>30%), and indirectly through replenishing our river systems (>20%), contributes over 50% of Australia's water supplies. Groundwater (and surface water) management in Australia faces intensifying pressures, from population expansion and increasing surface water scarcity in southern Australia posed by extreme drought and future climate change. Recently, and significantly, new additional pressures on groundwater systems have emerged through the rapid expansion of new energy sources (coal seam gas, uranium, geothermal and carbon geo-sequestration) and a rapid expansion of the minerals resource sector (including iron ore). The complexity and conflicts in the nexus between water, new energy, minerals and food and fibre security require innovative approaches in science, management and policy. This is particularly the case in the context of Australia's inherent vulnerability to climate change and the likely emergence of a carbon economy. Quantification of the hydrological cycle and catchment water balances in Australia is limited by a lack of spatial and temporal data. While substantial effort has been put into developing approaches for the mapping and quantification of surface hydrology, resources and processes, significant uncertainty remains in the knowledge of the size of Australian groundwater resources, their locations, rates of recharge, connectivity with surface waters and rates of use or depletion. Recently completed groundwater audits and regional groundwater investigations have made valuable assessments of resources based on limited available data, but have not adequately quantified the large uncertainties in groundwater model predictions and resource assessments, or identified where and what data and knowledge is required to improve these assessments.