Sandstone deposits are important sources of uranium, accounting for approximately 20 percent of global production, largely through in situ leach (ISL) mining. Most of this production has come from deposits in the western US, Niger and Kazakhstan. In Australia, sandstone-hosted uranium is being produced from the Beverley deposit in the Frome Embayment of South Australia, and a second ISL mine is under development at Honeymoon in the same region. Such deposits form where uranium-bearing oxidised ground waters moving through sandstone aquifers react with reducing materials. The locations of ore zones and the sizes of mineral deposits depend, amongst other factors, on the abundance and the reactive nature of the reductant. Hence the nature and abundance of organic material in the ore-bearing sedimentary sequence may be of critical importance in the formation of sandstone uranium deposits. In sandstones rich in organic material (containing debris of fossil plants or layers of authigenic organic material) the organic materials either reduce uranium directly with bacteria as a catalyst, or result in production of biogenic H2S. In sandstones relatively poor in organic material, that the reduction can be caused either by the introduction of hydrocarbons and/or H2S from oil/gas fields within underlying sediments; or by H2S produced from the interaction of oxidised ground water with pyrite in the sandstone aquifer. This paper outlines the geology of the world-class sandstone uranium deposits in the Chu-Sarysu and Syr-Darya Basins in the south-central portion of Kazakhstan, which are hosted by sandstones relatively poor in organic matter. It highlights the crucial role of that hydrocarbons appear to have played in the formation of these and other large sandstone type uranium deposits. Based on the model developed, it is concluded that there is considerable potential in Australia for discovery of large sandstone hosted uranium mineralisation, including in little explored regions underlain by basins with known or potential hydrocarbons.

AUSPOS is Geoscience Australia's on-line static GPS positioning service, providing user access to a state-of-art analysis system via a simple web-interface. Since its launch in 2001, AUSPOS has continued to be a widely used tool for the online processing of geodetic GPS data for surveying, mapping, geodetic, geophysical, hydrographical, mining, construction, military and other applications. On 20 March 2011, Geoscience Australia released an updated version of the service. The updated AUSPOS implements recent advances in analysis software and strategies, the reference frame ITRF2008, AusGeoid09 and the latest transformation parameters between ITRF2008 and GDA94. AUSPOS now delivers precise ITRF2008 coordinates to users within 3-5 minutes while continuing to provide Australian users with access to GDA94 coordinates and derived AHD heights to the highest achievable accuracy by simultaneously processing up to 7 days of user-supplied GPS data from up to 20 sites. The updated AUSPOS also provides more realistic coordinate uncertainty of its solutions using a recently developed assessment method of coordinate uncertainty, which is based on the duration of data sets and their global location. In this presentation, the current status of AUSPOS will be overviewed as well as plans for its ongoing improvement.

Scientists within Geoscience Australia create complex 3D models of geological structures, using specialised 3D modelling software. Very few people outside Geoscience Australia have access to this specialised software. To provide clients and stakeholders with access to 3D information Geoscience Australia has developed VRML-HTML-JavaScript interfaces. These interfaces allow Geoscience Australia to share large volumes of complex 3D geological information via the Web, with data volumes up to 22 MB. A number of methods are employed to allow users to interact with such large amounts of data. The geometric features within VRML are used to represent a wide range of geological features. The interfaces are user friendly and provide users with a high level of interaction with the complex information.

Advances in computer technology have provided the opportunity to present geoscience information in new and innovative ways. The use of web-based three-dimensional interactive models, animations and fly-throughs significantly enhances our ability to communicate complex geometries and concepts not only to the geoscientific community but also, just as importantly, to the general public. Projects within Geoscience Australia currently use a range of GIS, remote sensing, and modelling packages for visualisation of fundamental and derived data. In the main each of these packages also has the ability to produce, as an output, some form of model or animation sequence displaying the results of the visualisation. In most cases however, these outputs are generally not of sufficient quality or do not provide adequate functionality without further processing or editing. Geoscience Australia has adopted a multi-disciplinary approach to 3D visualisation encompassing cartography, GIS, remote sensing, graphic design, programming, web, and video editing to the post-processing of these visualisations. This paper examines the benefits of using models and movies for the visualisation of geoscience and briefly discusses the current workflows and presentation techniques used by the Geo-Visualisation team within Geoscience Australia.

Abstract for IGNSS 2015 conference: A Global Navigation Satellite System (GNSS) antenna calibration facility has been established at Geoscience Australia, for determining individual antenna calibrations as well as aiding the establishment of typemean calibrations as used by the International GNSS Service (IGS). Studies have highlighted the importance of accounting for the variation in individual antenna calibrations for high precision positioning applications. In order to use individual antenna calibrations reliably, the repeatability of the calibration needs to be well understood. In this paper, we give an overview of the repeatability of calibrations for different antenna types. We also present a case study on the application of an individual GNSS antenna calibration in Australia and its effect upon positioning.

<p>Knowledge of extreme ocean climate is essential for the accurate assessment of coastal hazards to facilitate risk informed decision making in coastal planning and management. Clustered storm events, where two or more storms occur within a relatively short space of time, may induce disproportionately large coastal erosion compared to non-clustered storm events. Therefore this study aims to develop a statistical approach to modelling the frequency and intensity of storm events on the eastern and southern coast of Australia, with a focus on examining storm clustering. This paper presents the preliminary analysis of the recently developed methods and results when they are applied to a study site on the central coast of New South Wales, Australia. This study is a key component of the Bushfire and Natural Hazards CRC Project Resilience to clustered disaster events on the coast storm surge that aims to develop a new method to quantify the impact of coincident and clustered disaster events on the coast. <p>Extreme storm events at a given site can be described using multivariate summary statistics, including the events maximum significant wave height (Hsig), median wave period, median wave direction, duration, peak storm surge, and time of occurrence. This requires a definition of individual storm events, and so the current methodology firstly involves the extraction of independent storm events from a 30-year timeseries of observations. Events are initially defined using a peaks-over-threshold approach based on the significant wave height. The value of 95% exceedance quantiles (2.93 m) is adopted. Subsequently, these events are manually checked against sea-level pressure data to examine if closely spaced events are generated by the same meteorological system, and if so the events are combined. This means that the final event set is more likely to consist of statistically independent storm events. <p>Various statistical techniques are applied to model the magnitude and frequency of the extracted storm events. A number of variations on the non-homogenous Poisson process model are developed to estimate the event occurrence rate, duration and spacing. The models account for the sub-annual variations in the occurrence rate, temporal dependency between successive events, and the finite duration of events. The results indicate that in the current dataset, closely spaced events are more temporally spread out than would be expected if the event timings were independent, which we term anti-clustering. A particular marginal distribution is fitted to each variable, i.e. a Generalised Pareto (GP) distribution for Hsig, and Pearson type 3 (PE3) distributions for duration and tidal residual. Empirical marginal distributions are employed for wave period and direction. The joint cumulative distribution function of all storm magnitude statistics is modelled by constructing dependency structure using Copula functions. Two methods are tested: a t-copula and a combination of a Gumbel and Gaussian copulas. Comparison of modelled and observed scatterplots shows similar pattern, and the difference of using the two methods is marginal. The goodness-of-fit tests such as Komologorov-Smirnov (K-S) tests, Chi-square tests and AIC and BIC are used to quantitatively evaluate the fitting qualities and to assess model parsimony, along with graphical visualisations e.g. QQ plots. <p>Based on this approach, a set of long-term synthetic time-series of storm events (106) is generated using the event magnitude and timing suggested by the optimised models. These long-term synthetic events can be used to derive exceedance probabilities and to construct designed storm events to be applied to the beach erosion modelling.

The first large-scale projects for geological storage of carbon dioxide on the Australian mainland are likely to occur within sedimentary sequences that underlie or are within the Triassic-Cretaceous, Great Artesian Basin (GAB) aquifer sequence. Recent national1 and state2 assessments have concluded that certain deep formations within the GAB show considerable geological suitability for the storage of greenhouse gases. These same formations contain trapped methane and naturally generated CO2 stored for millions of years. In July 2010, the Queensland government released exploration permits for Greenhouse Gas Storage in the Surat and Galilee basins.An important consideration in assessing the potential economic, environmental, health and safety risks of such projects is the potential impact CO2 migrating out of storage reservoirs could have on overlying groundwater resources. The risk and impact of CO2 migrating from a greenhouse gas storage reservoir into groundwater cannot be objectively assessed without knowledge of the natural baseline characteristics of the groundwater within these systems. Due to the phase behaviour of CO2, geological storage of carbon dioxide in the supercritical state requires depths greater than 800m, but there are few hydrogeochemical studies of these deeper aquifers in the prospective storage areas. Historical hydrogeochemical data are compiled from various State and Federal Government agencies. In addition, hydrogeochemical information is compiled from thousands of petroleum well completion reports in order to obtain more information on the deeper aquifers, not typically used for agriculture or human consumption. The data are passed through a QC procedure to check for mud contamination and to ascertain whether a representative sample had been collected. The large majority of the samples proved to be contaminated but a small selection passed the QC criteria. The full dataset is available for download from GA's Virtual Dataroom. Oral presentation at "Groundwater 2010" Conference, 31 October - 4 November 2010, Canberra

The flood risk in many urban catchments is poorly understood. Legacy stormwater infrastructure is often substandard and anticipated climate change induced sea level rise and increased rainfall intensity will typically exacerbate present risk. In a Department of Climate Change and Energy Efficiency (DCCEE) funded collaboration between Geoscience Australia (GA) and the City of Sydney, the impacts on the Alexandra Canal catchment in the City of Sydney local government area have been studied. This work has built upon detailed flood hazard analyses by Cardno Pty Ltd commissioned by the City of Sydney and has entailed the development of exposure and vulnerability information. Significantly, the case study has highlighted the value of robust exposure attributes and vulnerability models in the development of flood risk knowledge. The paper describes how vulnerability knowledge developed following the 2011 Brisbane floods is extended to include key building types found in the inner suburb of Sydney. It also describes the systematic field capture of building exposure information in the catchment area and its categorisation into 19 generic building types. The assessment of ground floor heights from street view imagery using the Field Data Analysis Tool (FiDAT) developed at Geoscience Australia is also presented. The selected hazard scenario was a 100 year Annual Recurrence Interval (ARI) event with 20% increased rainfall intensity accompanied by a 0.55m sea level rise in Botany Bay into which the stormwater infrastructure discharges. The impact from the selected scenario was assessed in terms of monetary loss for four combinations. The combinations consist of two vulnerability model suites (GA and NSW Government) and two floor height attribution methods (assumed 0.15m uniformly and evaluated from street view imagery). It was observed that the total loss is higher in the case of assumed floor heights compared to FiDAT processed floor heights as the former failed to capture increased floor heights for newer construction. However, the loss is lower when only two vulnerability models developed by NSW Government are applied for the entire building stock in the region as two models produced a coarser modelling of the variety in the whole building stock. Abstract & Poster presented at Floodplain Management Association National Conference 2013: http://www.floodplainconference.com/papers2013.php

The Vulcan Sub-basin has been actively explored for over twenty years, with oil production from the Jabiru and Challis-Cassini fields, and the depleted Skua Field, all of which were sourced by the Upper Jurassic Lower Vulcan Formation within the Swan Graben. The need to discover other oil-prone petroleum systems led to this study focussing on oils that have a different composition to those of the aforementioned oils. Geochemical analyses (bulk and compound-specific isotopes, GC and GC-MS of saturated and aromatic hydrocarbons) have characterised the Vulcan Sub-basin oils and condensates into three families (Fig 1); a marine oil family (with some terrigenous influence) comprising Jabiru, Challis, Skua, Talbot and Tenacious; a terrestrially-influenced oil family comprising Maret, Montara, Padthaway and Bilyara which have more varied geochemistry; and, a family of condensates from Tahbilk, Swan and Eclipse. The composition of these condensates is more reflective of reservoir alteration effects (such as leakage and gas flushing) than the type of organic matter in their source rocks. The terrestrially-influenced oil family is located in the southernmost part of the Vulcan Sub-basin and in the northern Browse Basin, most probably having being source from the Lower-Middle Jurassic Plover Formation. The Plover Formation contains liquid-prone source rocks within the Skua Trough, albeit immature for hydrocarbon generation. Similar source rocks are believed to occur beneath the Swan and Paqualin grabens since oils with mixed composition are found at Puffin, Pituri and Oliver.

Scientists within Geoscience Australia create complex models of 3D geological structures. These models are built using specialised 3D modelling software to which very few people outside of Geoscience Australia have access. To overcome this access problem, Geoscience Australia has developed 3D VRML (Virtual Reality Modelling Language) models, to display interactive 3D data using a web browser plug-in - hence 3D web mapping. VRML is an open source standard for 3D graphics on the web. Geoscience Australia's 3D web mapping development is unique and has proved to be a very effective method for communicating large amounts of complex 3D geoscientific and geospatial information to a wide audience. Geoscience Australia has produced nearly 40 unique 3D VRML models during the last five years, some of which are available for online interaction on the Geoscience Australia website. The next challenge for Geoscience Australia's visualisers is to move from VRML to X3D - the XML successor to VRML. This paper outlines the motivations for developing 3D VRML models, explains the technologies used, and takes a brief look at possible future developments.