Poster prepared for International Association of Hydrogeologists Congress 2013 This study was undertaken to establish a chronology for Quaternary fluvial landscape in the Darling River floodplain area. This was required to constrain the 3D mapping of floodplain units and to constrain conceptual models of surface-groundwater interaction. The lower Darling Valley contains Cenozoic shallow marine, fluvial, lacustrine and aeolian sediments including a number of previously poorly dated Quaternary fluvial units associated with the Darling River and its anabranches. New geomorphic mapping of the Darling floodplain that utilises a high-resolution LiDAR dataset and SPOT imagery, has revealed that the Late Quaternary sequence consists of scroll-plain tracts of different ages incised into a higher more featureless mud-dominated floodplain. Furthermore, the Understanding the relationships between these geomorphic units Samples for OSL (Optically-Stimulated Luminescence) and radiocarbon dating were taken in tractor-excavated pits, from sonic drill cores and from hand-auger holes from a number of scroll-plain and older floodplain sediments in the Menindee region. The youngest, now inactive, scroll-plain phase, associated with the modern Darling River, was active in the period 5-2 ka. A previous anabranch scroll-plain phase has dates around 20 ka. Indistinct scroll-plain tracts older than the anabranch system, are evident both upstream and downstream of Menindee and have ages around 30 ka. These three scroll-plain tracts intersect just south of Menindee but are mostly separated upstream and downstream of that point. Older dates of 50 ka, 85 ka and >150 ka have been obtained from lateral-migration sediments present beneath the higher mud-dominated floodplain. Age dating of the Quaternary fluvial sediments has been used to constrain a model of landscape evolution, neotectonics and recharge dynamics. Geomorphic and structural mapping identified a number of structural lineaments in the LiDAR data. These structures are coincident with mapped faults at depth in airborne electromagnetic (AEM) and airborne magnetic (and gravity) data. Those faults mapped at surface have varying landscape expression, with many re-worked by younger scroll-plain tracts. Younger faults appear to play a role in surface-groundwater interaction, while older faults are important for inter-aquifer leakage.

Tarawa is a coral atoll in the Gilbert Islands; it consists of a number of low islands, several of which contain discrete freshwater lenses overlying salt water. Resistivity depth probes indicate that the largest untapped lens is on the northern island of Buariki, and that this lens is up to 29m thick. The total safe yield of the Tarawa freshwater lenses is probably more than 12 1/s,and there is scope for the present groundwater development system of infiltration galleries to be extended.

Under the Community Stream Sampling and Salinity Mapping Project, the Australian Government through the Department of Agriculture, Fisheries and Forestry and the Department of Environment and Heritage, acting through Bureau of Rural Sciences, funded an airborne electromagnetic (AEM) survey to provide information in relation to land use questions in selected areas along the River Murray Corridor (RMC). The proposed study areas and major land use issues were identified by the RMC Reference Group at its inception meeting on 26th July, 2006. This report has been prepared to facilitate recommendations on the Barr Creek - Gunbower study area. The work was developed in consultation with the RMC Technical Working Group (TWG) to provide a basis for the RMC Reference Group and other stake holders to understand the value and application of AEM data to the study area. This understanding, combined with the Reference Groups assessment of the final results and taking in account policy and land management issues, will enable the Reference Group to make recommendations to the Australian Government.

Hydrogeological investigations in two pediplain basins at Lanyon, in the southern Tuggeranong Valley of the ACT, have identified areas which require remedial drainage for urban development. The rocks of the central Lanyon area consist of faulted Silurian dectic to rhyolitic ash-flow tuffs and interbedded sediments. Significant storage and transmission of groundwater occurs in well developed sets of open tensile fractures which formed in response to at least two reversals in regional principal stress directions during epeirogenic uplift and erosional unloading. Hydrogeological parameters measured in the field and laboratory included infiltration capacities, effective proosities, and hydraulic conductivities. From these data a predictive model for drain spacings is developed for all hydrogeological populations and for any given rainfall event. Constraints on locations of drains are also identified. It is recommended that a sufficient number of bores and piezometers be preserved after urban development to adequately assess changes to the groundwater regime.

Legacy product - no abstract available

Legacy product - no abstract available

The Southern Thomson Orogen VTEMplus® AEM Survey was undertaken as part of Geoscience Australia's contribution to the Australian Academy of Science's UNCOVER initiative, adopted as part of the Australian Government's National Mineral Exploration Strategy. Survey planning was in conjunction with our State survey partners, the Geological Survey of New South Wales and the Geological Survey of Queensland. The aim of the survey was to demonstrate the application of the AEM technique as an under-cover mapping and exploration tool by generating new data and information regarding depth to basement (DTB) and cover character in the under-explored southern Thomson Orogen region. The ultimate goal of the Southern Thomson Project is to encourage industry investment in this poorly understood area to discover a new minerals province.

This product has been archived and while it is still available for download, Geoscience Australia can no longer offer related support or advice. Legacy product - no abstract available

Legacy product - no abstract available

A summary of the presentations and outcomes of the 5th Technical Advisory Group workshop for the Palaeovalley Groundwater project.