This preliminary report will provide a geochemical and ionic characterisation of groundwater, to determine baseline conditions and, if possible, to distinguish between different aquifers in the Laura basin. The groundwater quality data will be compared against the water quality guidelines for aquatic ecosystem protection, drinking water use, primary industries, use by industry, recreation and aesthetics, and cultural and spiritual values to assess the environmental values of groundwater and the treatment that may be required prior to reuse or discharge.

Regional geology and prospectivity of the Aileron Province in the Alcoota 1:250 000 mapsheet area

This Record presents data collected as part of the ongoing NTGS-GA geochronology project between July 2012 and June 2013 under the National Geoscience Agreement (NGA). In total, 6 new U-Pb SHRIMP zircon and monazite geochronological results derived from 6 samples from the Amadeus Basin, Arunta Region and Murphy Province in the Northern Territory are presented herein (Table 1). Two metasedimentary samples were collected from the Amadeus Basin (ILLOGWA CREEK1) and two samples from the Arunta Region: garnet-biotite gneiss on ILLOGWA CREEK and biotite granite from HUCKITTA. One metasedimentary and one igneous sample were sampled from the Murphy Province (CALVERT HILLS). Six additional samples were submitted for SHRIMP analysis but did not yield any zircon.

The subsidence histories of most, but not all, basins can be elegantly explained by extension of the lithosphere followed by thermal rethickening of the lithospheric mantle to its pre-rift thickness. Although this model underpins most basin analysis, it is unclear whether subsidence of rift basins developed over thick lithosphere follows the same trend. Here the subsidence history of the Caning rift basin of Western Australia is modelled which putatively overlies lithosphere - 180 km thick, imaged using shear wave tomography. The entire subsidence history of the, < 300 km wide and <6 km thick, western Canning Basin is adequately explained by Ordovician rifting of ~120 km thick lithosphere followed by post-rift thermal subsidence as described by the established model. In contrast, the < 150 km wide and 15 km thick Fitzroy Trough of the eastern Canning Basin, reveals an almost continuous phase of normal faulting between Ordovician and Carboniferous Periods followed by negligible post-rift thermal subsidence which cannot be accounted for by the established model. This difference in basin architecture is attributed to rifting of thick lithosphere constrained by the presence of diamond bearing lamproites intruded into the basin depocentre at ~20 Ma. In order to account for the observed subsidence, at standard crustal densities, the lithospheric mantle is required to be depleted by 50-70 kg m-3. The actual depletion of the lowermost lithospheric mantle was assessed by modelling REE concentrations of the ~20 Ma lamproites along with other ultrapotassic rocks from the Kimberley, Yilgarn and Pilbara blocks which reveal a depletion of 40-70 kg m-3. Together these results suggest that thinning of thick lithosphere to thicknesses > 120 km is thermally stable and is not accompanied by post-rift thermal subsidence driven by thermal rethickening of the lithospheric mantle. The discrepancy between estimates of lithospheric thickness derived from subsidence data in the Western Canning and that derived from shear wave tomography suggests that the latter technique cannot resolve lithospheric thickness variations on < 300 km half wavelengths.

Geoscience Australia has collaboratively developed a number of open source software models and tools to estimate hazard, impact and risk to communities for a range of natural hazards to support disaster risk reduction in Australia and the region. These models and tools include: - ANUGA - a collaboration between the Australian National University (ANU) and GA to develop hydrodynamic software; - EQRM - earthquake risk model; - TCRM - tropical cyclone risk model; - PythonFall3D - python wrapper for an existing volcanic ash model; - TsuDAT - a collaboration between GA, the Australia-Indonesia Facility for Disaster Reduction, the ANU National Computing Infrastructure (NCI), OpenGeo and the World Bank to develop the tsunami data access tool; - RICS - rapid inventory collection system; - FiDAT - field data analysis tool. This presentation will discuss the drivers for developing these models in open source software and the benefits to the end-users in the emergency management and planning community as well as the broader research community. Key challenges in the risk modelling process will be discussed and how these may be addressed through the enhancement of existing models and the development of new models and workflows. Example challenges include image analysis for the development of building information from high resolution photography, project of future communities and reducing uncertainty in the frequency of natural hazard events. These challenges can be progressed through collaboration in the mathematical community.

Seismic interval velocities derived from stacking velocities can provide some clues to determination of rock lithology. This concept has been applied to understand the divergent dipping reflector (DDR) and seaward dipping reflector (SDR) packages over the Wallaby Plateau and Wallaby Saddle that were imaged on the 2008/2009 seismic survey GA310 contracted by Geoscience Australia. Root mean square velocities (Vrms) used to calculate interval velocities (Vint) were derived from long cable data. Vrms were picked on traces after pre-stack time migration, and the 4th order normal move-out (NMO) correction was implemented. Therefore, distortions to interval velocities due to insufficient curvature of NMO curve at short offsets, structural dip and ray bending due to stratification are assumed to be largely suppressed. Consequently Vrms velocities are assumed to approximate average velocities.

Groundwater can be a useful sampling medium for geological investigation and mineral exploration: its composition is highly sensitive to its origin and interaction with minerals in the subsurface, and it responds to faults and other geological structures. Thus there is considerable scope for groundwater adding value to mineral exploration where prospective rocks are covered along basin margins. We are encouraging the uptake of a groundwater hydrogeochemistry to aid mineral exploration through the development of robust and cost-effective methodologies based on numerous site studies. Field guides, notebooks, and field apps are now available. Issues such as bailing vs pumping have been tested, and metrics for contamination and determination of its effects on varying elements have been developed. Vast amounts of groundwater data are publicly available (e.g., http://portal.auscope.org/portal/gmap.html). Mineral systems concentrate various elements in particular zones of the Earth at various spatial scales. For groundwater, this is further complicated by the differing mobilities of various elements depending on the environment. In acidic groundwater environments, for instance, base metals (such as Cu, Zn) are highly mobile, although the background concentrations also can be high due to acid attack on the country rocks. In neutral groundwater environments, base metals commonly have low mobilities but oxy-anions (such as MoO42-, WO42-, AsO43-) can give larger and more consistent haloes. In some terrains, particularly in southern Australia, the upper 20 m of the water column can be 3 pH units lower than deeper groundwater. In such a situation, combining results from shallow and deep groundwaters will give erroneous spatial patterns. Interpreting groundwater geochemical data at the continental scale has required resolving issues related to differing analytical quality, and sometimes differing sampling and analytical methods. Results provide support for litho-chemical discrimination of the Australian continent, and allow assessment of the utility of these methods for varying terrains, e.g., from very acid/saline in southern Australia, through mostly fresh and neutral in the western two thirds of the continent, to sulfate-poor in the artesian-dominated systems of northeastern Australia. In each case, differing element suites and indices should be used for exploration. At the terrain scale, specific groundwater indices delineate large-scale lithological groups and major mineral camps. Such a broad-scale approach may obscure camp-scale variation but does delineate major features, such as the Agnew and Granny Smith gold camps in Western Australia. Other large mineral systems, such as iron-oxide copper gold (IOCG) or copper porphyries may also be observable. At the prospect scale, indicator elements (such as Au, Ni, Cu, Zn, W, As) are commonly valuable, with indices (such as `AuMin or `NiS) developed for specific commodities. Combined with geophysics, this may assist in selecting drilling targets. Hydrogeochemistry, combined with a robust understanding of environmental factors, weathering processes and good quality analytical chemistry, can positively assist exploration at various scales. Continuing research and interaction with explorers has the potential to contribute to the next phase of economic mineral discovery.

In the southern half of Australia, recent droughts and predictions of a drier future under a number of climate change scenarios have led to the search for innovative strategies to identify more secure water supplies for regional communities and industries, while also delivering environmental benefits to threatened river systems. These issues are of particular concern in the Murray-Darling Basin (the Basin), where the recent Millennium Drought (late 1990's - 2010) adversely affected many communities, industries and the environment. It has long been recognized that one of the areas with the greatest potential to contribute water savings in the Basin is at the Menindee Lakes Storages (MLS), located on the lower section of the Darling River in far western New South Wales. The MLS provide the main (up to 2,050 GL) water supply storage in the lower Murray-Darling River system, and play a significant role in meeting South Australia's water requirements. The shallow nature of the MLS, which are located in a hot, windy, semi-arid environment, results in an average evaporation loss across the MLS of 420 GL per year. Changing the management of the MLS to reduce these evaporative losses and provide enhanced water security for Broken Hill is possible, but Broken Hill's water supply would need to become less reliant on the MLS. To address these issues, in 2008 the Australian Government commissioned studies to reduce evaporation and improve water efficiency at the MLS, secure Broken Hill's water supply, protect the local environment and heritage, and return up to 200 GL to the Basin. As part of a broader suite of scientific and technical investigations, the Broken Hill Managed Aquifer Recharge (BHMAR) project was tasked with assessing the viability of Managed Aquifer Recharge (MAR) and/or groundwater extraction options to provide improved drought security for Broken Hill (Lawrie et al., 2012). An initial scoping study assessed options within a 150 km radius of Broken Hill, while Phase 1 of the BHMAR project narrowed the search to an area of the Darling Floodplain near Menindee. Based on the findings of these scoping studies, the BHMAR project was subsequently tasked with identifying and assessing: - Alternative groundwater-related water supply options for Broken Hill that could provide enhanced drought security for periods up to 3 years (~30 GL), within 50 km (later reduced to a radius of 20km) of existing water and energy infrastructure at Menindee on the River Darling Floodplain; - Groundwater resources and potential MAR opportunities that could provide enhanced drought security for regional communities and industries (e.g. agriculture and mining). To this end, a larger area (~7,500 km2) of the Darling Floodplain has been studied. Data acquisition utilised a phased approach, and was guided by the two main project objectives, and the requirement to address very specific scientific and technical questions embedded with national MAR guidelines. Initially, a data acquisition program was designed to map and assess groundwater resources and MAR opportunities in 4 main aquifers: - Shallow (0-30m) alluvial (unconfined) sand aquifers associated with the Darling River and it's Anabranches (Coonambidgal Formation and Menindee Formations); - Intermediate depth (30-100m) Pliocene Calivil Formation and Loxton-Parilla Sands (semi-confined to confined) aquifers. These were the primary target; - Deeper level (180-250m) Renmark Group Formation (confined) aquifers; - Shallow (<100m) Palaeozoic (Devonian and older) basement aquifers, in buried basement palaeo-topographic highs (sandstone, weathered zone and fractured rock aquifers).

Geoscience Australia (GA) has been developing the National Exposure Information System (NEXIS), a national database of exposure information to identify elements in both the built environment and community that are at risk from natural disasters. A key component of NEXIS is the description of each building including footprint area and height; these geometric characteristics can be derived from LiDAR. This investigation is an assessment of the current abilities of GA and industry partners to provide this data. GA holds LiDAR data representing 70% of the places Australians live, however most of these dataset have not been processed to identify buildings. Five software methods and five industry partners were assessed for their ability to do two main tasks: identify or classify buildings in the LiDAR point clouds, and extract geometric characteristics of buildings. The extracted features were assessed using an urban LiDAR point cloud that has good accuracy and a high data density. Feature-based and area-based assessment methods were developed to assess the output of software packages against a reference building dataset provided by the Launceston Council. The various methods achieved a producer's accuracy between 80% and 90%, user's accuracy between 70% and 90%, and overall accuracy between 90% and 95%.

This collaborative project between Geoscience Australia (GA) and CSIRO aims to use physicochemical measurements, collected from surface overbank sediments as part of the National Geochemical Survey of Australia (NGSA) project, to help validate the ASTER multispectral geoscience maps of Australia. Both data sets have common information including that related to the surface abundance of silica, aluminium, iron, clay, sand and volatiles (including carbonate). The ASTER geoscience maps also provide spatial information about trends of mineral composition, which are potentially related to pH and oxidation state.