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.

This report gives an overview of the activities of the Geoscience Australia IVS Analysis Center during 2012

Preliminary zircon data and tectonic framework for the Thomson Orogen, northwestern NSW

2013 Acreage Release Areas W13-19 and W13-20 in the offshore northern Perth Basin, Western Australia, cover more than 19,000 km2 in parts of the Houtman, Abrolhos, Zeewyck and Gascoyne sub-basins. The Release Areas are located adjacent to WA-481-P, the only offshore exploration permit active in the Perth Basin, granted to joint venture partners Murphy Australia Oil Pty Ltd, Kufpec Australia Pty Ltd and Samsung Oil and Gas Australia Pty Ltd in September 2012. Geoscience Australia recently undertook a regional prospectivity study in the area as part of the Australian Government's Offshore Energy Security Program. A revised sequence stratigraphic framework, based on new biostratigraphic sampling and interpretation, and an updated tectonostratigraphic model, using multiple 1D burial history models for Permian to Cenozoic sequences, give fresh insights into basin evolution and prospectivity. Geochemical studies of key offshore wells demonstrated that the late Permian's Lower Triassic Hovea Member oil-prone source interval is regionally extensive offshore in the Abrolhos and potentially Houtman sub-basins. This is supported by fluid inclusion data that provides evidence for palaeo-oil columns within Permian reservoirs in wells from the Abrolhos Sub-basin. Additionally, oil trapped in fluid inclusions in Houtman-1 can be linked to Jurassic source rocks suggesting that multiple petroleum systems are effective in the Release Areas. A trap integrity analysis was undertaken to mitigate exploration risks associated with trap breach during Early Cretaceous breakup and provides a predictive approach to prospect assessment. Potential seepage sites on the seafloor over recently reactivated faults correlate with hydroacoustic flares, pockmarks and dark colored viscous fluid observed over the areas. These observations may indicate an active modern-day petroleum system in the Houtman Sub-basin. The presence of a Jurassic petroleum system combined with the extension of the Hovea Member source rock offshore, the potential presence of seeps and results from trap integrity studies provide a platform to revitalize exploration in the offshore northern Perth Basin. The APPEA Journal

The Murray River is known to display great complexity in surface-groundwater interactions along its course, with 'gaining' sections of the river identified as sites of regional saline groundwater system discharge to the river and the adjacent floodplain. 'Losing' reaches of the river occur where river water infiltrates through the base of the river and recharges underlying aquifers and/or where adjacent aquifers are recharged through lateral bank infiltration. Recent studies have shown that recharge is not-steady state, with surface-groundwater processes promoted after river bank scouring during major flood events. 'Losing' reaches of rivers are hard to identify hydrochemically, while only airborne electromagnetic (AEM) methods provide 3D spatial mapping of salinity and hydrostratigraphy at depth beneath the river and across the floodplain. In 2007 a regional airborne electromagnetic (AEM) survey (24,000 line km @ 150m line-spacing in a 20 km-wide swath) was acquired along a 450 km reach of the Murray River in Victoria from Gunbower Island in the east to near the South Australian border. The AEM survey was calibrated and validated by drilling and complementary field mapping, and lithological and hydrogeochemical investigations. Holistic inversions of the AEM data were used to map key elements of the hydrogeological system and salinity extent in the shallow sub-surface (top 20-50 m). The survey successfully mapped key elements of the hydrogeological system including previously unmapped salinity discharge zones and significant losing 'flush' zones. Significant 'flush' zones to depths of 25m and up to 1.5 km in width have been identified at Turrumbarry Weir, with other significant zones identified in parts of Gunbower Forest, and between Liparoo and Robinvale. Elsewhere, flush zones are smaller, and occur at depths of 5-10m in narrower zones associated with locks, weirs and irrigation districts. Salt mobilisation associated with the flush zones at weir pools may be an issue in terms of salt load delivery to the River Murray and floodplain. Reaches of the river where the flush zones are absent and /or significantly constricted, and similar zones in tributary creeks in the adjacent floodplain, are at higher risk of saline groundwater inflows.

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.

Understanding the potential magnitude, severity and impact of future volcanic eruptions on communities living in close proximity to volcanic sources is essential for any attempt to reduce natural disaster risk in Papua New Guinea. Geoscience Australia is working in partnership with the Rabaul Volcanological Observatory (RVO) to build the capacity of volcanologists to undertake volcanic ash dispersal modelling, to interpret the outputs and to incorporate the data where appropriate into a new series of volcanic hazard maps for a pilot province (East New Britain; ENB). A modified procedure for volcanic ash dispersal modelling (PF3D) was developed in 2009 by Geoscience Australia and its regional partners in Indonesia and the Philippines which modify the modelling procedure of FALL3D, a widely used and well validated volcanic ash dispersal model, in line with the needs of government agencies and emergency managers in the Asia-Pacific region. PF3D introduces a number of enhancements to the procedure for FALL3D that do not change the operation or functionality of the core model but increase its accessibility for volcanologists working in developing countries like Papua New Guinea. The three year program, funded by the Australian Agency for International Development (AusAID) provided training in the use and application of PF3D for RVO staff through the development of new volcanic hazard and risk information for ENB. A significant achievement for the program has been the continuous involvement of community groups who, through a series of workshops held in ENB, have been heavily involved in discussions around the kind of volcano science being undertaken, providing feedback on outputs and in driving the design and production of education and public awareness materials (books, posters etc) which will be used for communicating the outputs of the program in local schools and other community centres as part of a larger planning and preparedness campaign.

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.