A brief summary fo the highlights of the Paterson AEM survey and planned future work of Geoscience Australia's Airborne EM Project.

Airborne electromagnetic (AEM) data are being acquired by Geoscience Australia (GA) under the Australian Government's Onshore Energy Security Program (OESP) in areas considered to have potential for uranium or thorium mineralisation. In contrast to deposit-scale investigations carried out by industry these surveys are designed to reveal new geological information at a regional scale. The Frome AEM survey shown in Figure 1 was flown by Fugro Airborne Surveys for GA, using the TEMPESTTM time-domain system. The survey was conducted with the aims of reducing exploration risk, stimulating exploration investment and enhancing prospectivity within the region primarily for uranium, but also for other commodities including copper, gold, silver, lead, zinc, iron ore and potable groundwater. The Frome AEM survey was primarily designed to be a regional mapping program for mapping surface and subsurface geological features that may be associated with sandstone-hosted uranium systems. The data are also capable of being interpreted for landscape evolution studies within the flanks of the tectonically active Curnamona Province and Flinders Ranges of South Australia. In this article we present an enhanced set of conductivity estimates which are now available from the GA website free of charge. These conductivity estimates reveal new geological information

Extended abstract regarding the Frome AEM data set and Murray Basin geology and landscape evolution

<p>This data package contains three airborne geophysical datasets that have been acquired and processed from the Lower Macquarie River TEMPEST AEM survey flown in 2007, located to the north-west of Dubbo in the Central West region of New South Wales. The datasets are: a new Geoscience Australia layered earth inversion (GA-LEI) of the 2007 Lower Macquarie River TEMPEST Airborne Electromagnetic (AEM) survey; an airborne magnetic survey; and a digital elevation model (DEM). These data include enhancements of previously available datasets using more recent geophysical processing software advances. <p>This metadata briefly describes the contents of the data package. The user guide included in the package contains more detailed information about the individual datasets and available technical reports. <p>The AEM dataset comprises the final Geoscience Australia layered earth inversion (GA-LEI) of the Lower Macquarie River TEMPEST AEM survey data, produced in 2008. The main data products from the GA-LEI inversion are: point located inversion output data; horizontal layer conductivity grids below ground surface; horizontal conductivity-depth slice grids of various regular depth intervals below ground surface; vertical conductivity-depth sections along each flight line; AEM survey outline and flight line vector GIS data; and borehole comparison logs. The GA-LEI AEM data are derived from the 'Lower Macquarie River TEMPEST AEM Survey, NSW, 2007 Final Data (P1140)', available as Geoscience Australia product number 67211 (GeoCat #67211). The GA-LEI has been demonstrated to generate more accurate conductivity predictions than other algorithms for similar TEMPEST surveys. <p>The airborne magnetics and DEM data in this data package includes the corresponding data from GeoCat #67211, with additional raster and image formats to facilitate accessibility on a range of geographic information system platforms. <p>The point located data are stored in ASCII files (.asc) formatted with space-delimited columns with an associated comprehensive header (.hdr) file. The gridded data are stored in ER Mapper and ESRI grid formats as binary floating point raster grid files. The image data are stored in GeoTIFF format with associated world (.tfw) files and (.png) legends. The vector data are stored in ESRI shapefiles (.shp) Technical reports are stored in Portable Document Format (.pdf). The datasets are compressed in ZIP files. <p>The TEMPEST time domain airborne electromagnetic (AEM) survey was flown by Fugro Airborne Surveys over the Lower Macquarie River catchment in 2007. The survey was commissioned by the Australian Government Department of Agriculture, Fisheries and Forestry through the Bureau of Rural Sciences (BRS), now known as the Australian Bureau of Agricultural and Resource Economics and Sciences (ABARES) and funded under the National Action Plan for Salinity and Water Quality. Geoscience Australia (GA) provided several geophysical services in relation to the survey including survey planning, technical system selection, data quality control and layer earth inversion of the resultant data. Format conversion of the magnetics and DEM data in this product was performed by ABARES from data provided by GA.

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.

This report describes the geological and uranium energy implications of the Paterson airborne electromagnetic survey.

A guide to the use of AEM geophysics for mapping SWI in coastal landscapes and karstic aquifer systems in Australia. The project was funded by the National Water Commission (NWC), with significant in-kind resources and funding provided by Geoscience Australia (GA) and the Northern Territory Department of Resources, Environment, Tourism, Arts and Sports (NRETAS).

This dataset includes products derived from the Honeysuckle Creek airborne electromagnetic (AEM) survey (Geoscience Australia Airborne Geophysics Project number 903), which was acquired in 2001 near Shepparton in Victoria. The derivative products have been specially designed through the application of the Geoscience Australia Layered Earth Inversion (GA-LEI) algorithm, to facilitate easier use than the original data. However, they should only be considered depictions of the data, and the methods used in their generation instil their own biases. The dataset includes the following products derived from the GA-LEI results: - GA-LEI data in a point located or line format (ASCII format). - Vertical conductivity sections (JPEG and PDF format). - Conductance grids (ERMapper format) and images (JPEG format). - Conductivity depth slice grids (ERMapper format) and images (JPEG format). - Layer conductivity grids (ERMapper format). - Depth to basement grids (ERMapper format) and images (JPEG format). - 3-dimensional voxet of conductivity. The whole dataset is stored in 12 ZIP files, and should be referred to as Fisher and Brodie (2008b). For more information on all the files included in the dataset, as well as the methods used in creating the derivative products see Fisher and Brodie (2008a). REFERENCES Fisher, A.G. and Brodie, R.C., 2008a. Geoscience Australia LEI Products from the Honeysuckle Creek TEMPEST AEM survey, Victoria. Geoscience Australia Record 2008/12. Fisher, A.G. and Brodie, R.C., 2008b. Geoscience Australia LEI Products from the Honeysuckle Creek TEMPEST AEM survey, Victoria [Digital Dataset]. Geoscience Australia, Canberra.

This report describes the geophysical inversion of the Honeysuckle Creek TEMPEST airborne electromagnetic (AEM) survey data (Geoscience Australia Airborne Geophysics Project # 903) to produce subsurface electrical conductivity predictions using a layered earth inversion algorithm developed by Geoscience Australia (GA-LEI). It also describes the products that were derived from the GA-LEI subsurface electrical conductivity predictions. The GA-LEI algorithm has significantly improved on previous conductivity predictions generated by inversion and conductivity depth transform methods, as shown by comparisons between conductivity predictions and ground truth data (measurements of conductivity acquired down boreholes). While this comparison is best shown graphically, statistically speaking the correlation between the GA-LEI predictions and borehole measured conductivities (R2 = 0.77) is better than for previous predictions from inversions (R2 = 0.05 and 0.47), and conductivity depth transforms (R2 = 0.04 and 0.47). This improvement is attributed to the GA-LEI methodology, which solved for three unmeasured components of the system geometry as well as the ground conductivity model, and was guided by downhole conductivity and geological knowledge. In addition, the GA-LEI method used both the X and Z components of the measured response, and used minimally processed data which have fewer introduced assumptions than data previously used. Being an inversion, it compared the calculated response from the subsurface conductivity predictions with the measured response data, ensuring the conductivity predictions results are consistent with measured data, which was not done with previous transform methods. The subsurface electrical conductivity predictions produced by the GA-LEI were post-processed to produce a variety of derivative products. These products were designed to be used without specialised geophysical knowledge, however, they should only be considered depictions of the data, and the methods used in their generation have instilled their own biases. The main products derived from the GA-LEI results are: layer conductivities; conductivity depth slices; vertical conductivity sections; a conductance distribution; and, an estimate of the depth of the basement rocks beneath the regolith. These products have been enhanced, producing colour images stored in either the JPEG or PDF format. All products are available from the Geoscience Australia website (www.ga.gov.au).

During 2008 and 2009, and under the Australian Government's Onshore Energy Security Initiative, Geoscience Australia acquired airborne electromagnetic (AEM) data over the Pine Creek Orogen of the Northern Territory. The survey area was split into three areas for acquisition. VTEM data was acquired in the Kombolgie area east of Kakadu National Park between August and November 2008. TEMPEST data was acquired west of Kakadu National Park with the area split in two to facilitate the use of two aircraft: the Woolner Granite area in the north was acquired between October and December 2008; and the Rum Jungle area (this data set) adjoining to the south, which was acquired between October 2008 and May 2009. The main purpose of the surveys was to provide additional geophysical/geological context for unconformity style uranium mineral systems and thereby promote related exploration. The survey data will also provide information on depth to Proterozoic/Archean basement, which is of general interest to explorers, and will be used as an input into ground water studues in the region.