This Record presents data collected as part of the ongoing NTGS-GA geochronological collaboration between July 2000 and June 2011 under the National Geoscience Agreement (NGA). This record presents new SHRIMP U-Pb zircon and monazite geochronological results for 18 samples from the Arunta Region, Davenport Province, Simpson Desert and Pine Creek Orogen in the Northern Territory. Five Paleoproterozoic igneous and metasedimentary samples were collected from the Eastern Arunta (ILLOGWA CREEK), and one metasedimentary sample from the eastern Casey Inlier (HALE RIVER). One igneous volcanic sample and two metasedimentary samples are from the Davenport Province (MAPSHEET) and Simpson Desert regions (HAY RIVER), respectively. Ten samples in total were collected from the Pine Creek Orogen; one igneous sample from DARWIN, the remainder being igneous and metasedimentary samples from the Nimbuwah Domain (ALLIGATOR RIVER).

Known magmatic-related uranium mineralisation is rare in Australia, despite the widespread occurrence of uranium-rich igneous rocks. Known intrusive-related mineralisation is almost entirely restricted to South Australia, while uranium mineralisation related to volcanic rocks is mostly known from northern Queensland. This apparent discrepancy suggests that Australia is under-represented in this category of uranium mineral system, and as such, the potential for future discoveries is inferred to be high. Recent work by Geoscience Australia has sought to enhance the prospectivity for a range of uranium mineral system types in Australia, including those related to magmatic rocks, by undertaking regional scale assessments of the potential for these systems. Using a similar approach, an assessment for the potential for magmatic-related uranium mineral systems has been undertaken in a systematic manner on a national scale. This has been done in a GIS environment using the fuzzy logic method, which allows for uncertainty to be captured while being relatively easy to implement. Two subcategories of magmatic-related uranium systems have been assessed: intrusive- and volcanic-related. Rather than attempting to identify specific sites of mineralisation, this investigation has focused on delineating those igneous units and events which have the highest potential for a magmatic-related uranium mineral system to operate. This allows for potentially prospective tracts to be readily identified, in which the mineral potential and uranium depositional sites may be refined using detailed local knowledge and datasets. Potentially prospective igneous rocks have been identified in all States and Territories where uranium exploration is currently permitted, including regions already known for magmatic-related uranium occurrences. Significantly, this study has identified high potential in regions which are currently not well known for magmatic-related uranium mineralisation.

Note that this Record has now been published as Record 2014/050, GeoCat number 78802

In early 2011 PRL provided Geoscience Australia with the Old Drill Hole Clearing dataset. This dataset shows the location of old drill lines cleared through the rainforest on Christmas Island. Drill lines were cleared to test the land for phosphate deposits and were cleared from the 1960Âs through to the 1970Âs, before Phosphate Resources Limited (PRL) began mining on the island. No clearing of primary rainforest has occurred under PRL. This dataset can be combined with the Pre-PRL Clearing (pre_prl_clearing.shp) data to give a realistic representation of all cleared areas on the island. The dataset can be accessed from the CIGIS CD from the following path: C:\CIGIS\environment\old_dh_clearingextent_poly.shp

The OzCoasts web-based database and information system draws together a diverse range of data and information on Australia's coasts and its estuaries. Maps, images, reports and data can be downloaded and there are tools to assist with coastal science, monitoring, management and policy. The content is arranged into seven inter-linked modules: Search Data, Conceptual Models, Coastal Indicators, Habitat Mapping, Natural Resource Management, Landform and Stability Maps and Climate Change. The Climate Change module is the newest feature of the website and was developed in partnership with the Australian Government Department of Climate Change and Energy Efficiency. The module provides information and tools to help communicate the risks of sea-level rise and other potential impacts of climate change on coastal areas. It includes an elevation data and a modelling portal for access to existing and new elevation data and derived products, including sea level inundation maps for Perth to Mandurah, Melbourne, Sydney, Hunter and Central Coast & Brisbane and Gold Coast. The inundation footprints illustrate three sea level rise scenarios: a low (0.5m), medium (0.8m) and high (1.1m) scenario for a 2100 time period, with values based on IPCC projections (B1 and A1FI scenarios) and more recent science. OzCoasts will also soon deliver the Coastal Eutrophication Risk Assessment Tool (CERAT) for the NSW Department of Environment, Climate Change and Water, and the Australian Riverscape Classification Service (AURICL) for the Tropical Rivers and Coastal Knowledge (TRaCK) consortium. CERAT will help identify and prioritise land use planning decisions to protect and preserve the health of NSW estuaries. AURICL has a northern tropical focus, and is a dynamic and flexible system for classifying catchments and their rivers based on the similarity, or dissimilarity, of a wide range of parameters.

Climate change is expected to increase severe wind hazard in many regions of the Australian continent with consequences for exposed infrastructure and human populations. The objective of this paper is to provide an initial nationally consistent assessment of wind risk under current climate, utilizing the Australian/New Zealand wind loading standard (AS/NZS 1170.2, 2002) as a measure of the hazard. This work is part of the National Wind Risk Assessment (NWRA), which is a collaboration between the Australian Federal Government (Department of Climate Change and Energy Efficiency) and Geoscience Australia. It is aimed at highlighting regions of the Australian continent where there is high wind risk to residential structures under current climate, and where, if hazard increases under climate change, there will be a greater need for adaptation. This assessment is being undertaken by separately considering wind hazard, infrastructure exposure and the wind vulnerability of residential buildings. The NWRA will provide a benchmark measure of wind risk nationally (current climate), underpinned by the National Exposure Information System (NEXIS; developed by Geoscience Australia) and the wind loading standard. The methodology which determines the direct impact of severe wind on Australian communities involves the parallel development of the understanding of wind hazard, residential building exposure and the wind vulnerability of residential structures. We provide the current climate wind risk, expressed as annualized loss, based on the wind loading standard.

Floods are Australia's most expensive natural hazard with the average annual cost of floods estimated at AUD$377 million (BITRE 2008). This figure is likely to have risen following the widespread and devastating floods across eastern Australia that occurred over the summer of 2010-11. The development of tools to support the identification and analysis of flood risk is an important first step in reducing the cost of floods in the community. The Australian Government through Geoscience Australia (GA) has been leading the development of tools which assist in flood intelligence, modelling and damage assessment. An overview of three of these tools will be provided in this presentation. Note: Rest of abstract is too long for space provided.

To investigate the standard electrical conductivity profile beneath a continent, we conducted a magnetotelluric (MT) observation with long dipole span near Alice Springs, central Australia. We utilized geomagnetic data acquired at the Alice Springs geomagnetic observatory operated by Geoscience Australia. Using the BIRRP processing code (Chave and Thomson, 2004), we estimated the MT and GDS (geomagnetic depth sounding) transfer functions for periods from 100 to 10 to 6 sec. The MT-compatible response functions converted from GDS response functions are resistive compared to the Canadian Shield (Chave et al., 1993) for periods around 10 to 5 sec. The calculated MT responses also have generally high apparent resistivity values over the entire period range. We inverted the average MT responses into a one-dimensional conductivity profile using Occam inversion (Constable et al., 1987). The resultant conductivity profile is extremely resistive (0.001 to 0.0001 S/m) down to the mantle transition zone. We compared this one-dimensional structure with electrical conductivity profiles predicted from compositional models of the earth's upper mantle by calculating phase diagrams in the CFMAS (CaO-FeO-MgO-Al2O3-SiO2) system. The on-craton and off-craton chemical composition models (Rudnick et al., 1998) were adopted for the tectosphere. The Perple_X (e.g. Connolly, 2005) programs were used to obtain mineral proportions and compositions with depth. The calculated conductivity profiles with on- and off-craton models show significantly larger magnitude than the observed. The result suggests the continental lithosphere (tectosphere) beneath Australia is extremely dry and its temperature profile is cooler than that used in the calculation.

There is a general acceptance amongst the analytical community that geological materials must be reduced to less than 75 microns grain size to reduce particle-size effects and to reduce minerals sufficiently to provide a representative analysis of the sample. This study examines several aspects of this assumption, by comparing the XRF analysis of pressed powder pellets and fused glass discs of the same samples in coarse- and fine-grained form; quantifying the grain-size difference between these samples by laser particle size analysis. An examination of the effect that overloading a grinding head can have on the efficiency of grinding was also carried out. Coarse- and fine-grained aliquots of the same samples were pressed into powder pellets and trace elements analysed by a Philips PW2404 X-ray Fluorescence spectrometer. These same samples were fused into Lithium meta/tetra Borate discs and analysed for major elements by XRF. A sub-sample of this glass disc was acid-digested and trace elements analysed on an Agilent 7500CE ICP-MS. Results obtained were compared. Grinding head efficiency was examined by pulverising increasing weights of the same rock sample in a Rocklabs TC-200 Tungsten Carbide grinding head in a Rocklabs Standard Ring Mill. The same methodology as outlined above was then used to analyse the fractions and compare the results. A Malvern 2000E Laser Particle Size analyser was used to quantify the grain size of the samples analysed. Analytical results will be presented, highlighting the effects of the varying grain size.

Map compiled on request from AGS Native Title Case QUD6040/2001 Proclamation 6 See 2008/3111 for particulars.