AUSGeoid09 is an order of magnitude more accurate than AUSGeoid98 at converting ellipsoidal heights to Australian Height Datum (AHD) heights and vice versa. Results of this study show AUSGeoid09 can be used to compute AHD values from Global Navigation Satellite System (GNSS) ellipsoidal heights with an uncertainty of less than 0.03 m (1 sigma). The improvement is largely due to the inclusion of a geometric component in AUSGeoid09 that accounts for the spatially varying offset between a gravimetric quasigeoid model and the AHD. This geometric component was calculated using least squares collocation in cross validation mode and then 'draped' over the gravimetric quasigeoid. Although previous AUSGeoid models were used to convert GNSS ellipsoidal heights to the AHD and vice versa, none until now have accounted for the gravimetric quasigeoid to AHD offsets. This is a consequence of how the AHD was realised and has commonly resulted in misfits of ~0.5 m or more. When used with GNSS technology, AUSGeoid09 can replace the need for traditional third-order levelling in many situations. Relative tests of AUSGeoid09 over a continent-wide set of over 20 million baselines showed that it can deliver better than Australian class LC levelling tolerances (12 ) in 99% of cases. The model accepts a user's GDA94 latitude, longitude and ellipsoidal height and returns an AHD height and deflections of the vertical. AUSGeoid09 is now available free-of-charge on the Geoscience Australia website (http://www.ga.gov.au/geodesy/ausgeoid/nvalcomp.jsp).

In Australia the national network of GNSS Continuously Operating Reference Stations (CORS) provide the fundamental framework for all spatial activities and the linkage to the International Terrestrial Reference Frame (ITRF). Importantly, this national network also contributes data and products to the Global Geodetic Observing System (GGOS) for use in a variety of science applications. The Geocentric Datum of Australia 1994 (GDA94) was based on observations (1992 - 1994) from a sparse network of CORS called the Australian Fiducial Network. The resultant coordinate datum was estimated to have an uncertainty of 3cm horizontally and 5cm vertically at the AFN stations. Since that time the demand for higher accuracies has resulted in GDA94 no longer adequately serving user demand. The ITRF has continued to evolve in accuracy and distribution to the extent that it now allows very accurate measurement of linear and non-linear crustal deformation. Even the Australian Plate, which for GDA94's implementation was considered rigid, is now known to be deforming at levels detectable by modern geodesy. Consequently, national infrastructure development programs, such as AuScope, have been implemented to ensure that crustal deformation can be better measured. The AuScope program also aims to improve the accuracy of the ITRF by contributing to the next generation of the GGOS in our region. This approach will ensure that the ITRF continues to evolve and that Australia's National datum is integrally connected to it with equivalent accuracies. This paper reviews the status of National CORS networks and their contribution to GGOS and its impact on positioning in Australia.

Shared geological and geochemical processes are involved in the formation of particular groups of uranium deposits. Three families of uranium mineral systems are recognised: magmatic-, metamorphic- and basin-related. End-member fluids in each family are magmatic-hydrothermal, 'metamorphic' (including fluids reacted with metamorphic rocks at elevated temperatures), and surficial fluids such as meteoric water, lake water and seawater. Most well known uranium deposit types can be accommodated within this tripartite framework, which explicitly allows for hybrid deposit types.

Recognising the importance of improving the regional geodetic framework in the Asia-Pacific region, the Asia-Pacific Reference Frame (APREF) project call for participation was released in March 2010. The APREF project is a joint initiative of the Permanent Committee for GIS Infrastructure of the Asia-Pacific (PCGIAP) and the International Association of Geodesy (IAG). Currently, GNSS data from a Continuously Operating Reference Station (CORS) network of approximately 290 stations, contributed by 28 countries, is now available and processed by three Analysis Centres (ACs). The contributions of the ACs are combined into a weekly solution in SINEX format using the CATREF software. Three kinds of APREF products are available, rapid daily solutions which are produced using IGS rapid products, final daily solutions which are produced using IGS final products, and the weekly combined solutions. The core product of the APREF is the weekly solution; it provides a reliable time-series of the regional reference frame in the International Terrestrial Reference Frame (ITRF) and a quality assessment of the performance of participating Asia-Pacific GNSS CORS stations. In this presentation, we update the progress of the APREF project and perspectives towards a regional focus for cooperation in the definition, realisation and densification of the ITRF in the Asia-Pacific.

The Common Earth Model is a collection of data collated by Geoscience Australia that aims to give a unified overview of the geology of Australia. The data are visualised in the Geoscience Australia 3D Data Viewer software and the intention is to give users a rich environment to explore diverse geological data. Geoscience Australia has collated these datasets from a wide range of sources. Copyright in all content on the DVD remains with the originating organisations and individuals, and may not be reproduced without permission. The 3D Data Viewer software itself is released under Creative Commons Attribution 3.0.

Geophysical modelling, especially 3D inverse modelling, requires significant computational power due to the application of complex calculations to large datasets. To meet this need, parallelised codes running on a High-Performance Computing (HPC) are utilised to perform these geophysical modelling tasks. There are, however, often difficulties for scientists to access these codes and no consistency in approach to the preparation of input data to these codes. To reduce this complexity and lack of consistency access to parallel grid computing services via the internet, termed cloud computing, has been established for geophysical inverse modelling using the University of British Columbia, Geophysical Inversion Facility (UBC-GIF) codes GRAV3D and MAG3D. Portals and workflows have been developed to simplify the inversion modelling process and to allow more efficient access to inversion modelling tools. A mechanism which allows inversion modelling jobs to be submitted to cloud computing resources using a web browser (a geophysical portal) is being developed and tested at the National Computational Infrastructure (NCI) housed at the Australian National University (ANU). This work is the result of a collaborative project between Geoscience Australia, CSIRO and NCI.

Legacy product - no abstract available

Legacy product - no abstract available

Legacy product - no abstract available

Although extensive geochemical baseline studies have been conducted in many countries, including the UK, Finland, Norway, Poland, USA, Japan, China and New Zealand, they have not been attempted in Australia. Where conducted elsewhere, geochemical baseline surveys have been used to 1) help determine the natural state of the environment, 2) contribute valuable information to help develop more informed environmental policies, and 3) provide potential targets for mineral exploration, 4) provide information for geohealth studies, in combination with epidemiological data. To make a start in this direction in Australia, a pilot study has been conducted to assess whether valid baseline information could be obtained through analyzing existing whole-rock geochemical data at both regional and local scales. The regional study focused on southeastern Australia, whilst the local study centered on the Bathurst 1:250 000 map sheet area. Data were drawn from Geoscience Australia?s large OZROCKS and OZMIN databases. The existing regional scale data had a highly variable sampling density and there was a strong possibility of a sampling bias being incorporated in the data analysis. To eliminate anomalies that were associated with known mining activities, mineral occurrence densities were also created and combined with maps of anomalous concentrations of uranium, lead, zinc, gold and arsenic. Whilst not ideal, these regional data still showed some broad scale trends and identified smaller target areas for more detailed work. As the Bathurst study area had a higher sample density, a more comprehensive analysis was possible. Statistical analysis was conducted to identify spurious and highly anomalous data, which were then removed from the dataset. The geochemical points were validated to ensure that they were located in the correct geological unit. This allowed the data to be viewed in their geological context. The geochemical values were then extrapolated across like geological polygons and trends of elemental concentrations in rock types became apparent. Although some useful information was obtained in both the regional and area-scale studies, the results were clearly influenced by the fact that the geochemical samples were collected for specific and disparate studies. Hence, it was concluded that existing whole-rock geochemical data are not generally appropriate for use in baseline geochemical surveys. This led to the acceptance that a new, carefully planned survey is needed to obtain useful baseline geochemical data for Australia. In recognition of this need, a pilot geochemical study involving Geoscience Australia and CRC LEME is currently underway in the Riverina bioregion, based on stream sediments/overbank sediments. It is hoped that this study will prove information that is sufficiently interesting to engender support for a systematic geochemical coverage across large portions of the continent.