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.

These grids represent the potentiometric surface of the Cadna-owie - Hooray Aquifer in the Great Artesian Basin at 20 year intervals from 1900-2010. They were interpolated from GAB water table elevations and from observations of hydraulic head obtained from state groundwater databases. Head measurements were density corrected prior to creation of surfaces. Where there were no temperatures supplied with the head measurement to allow correction, temperature was interpolated from dataset 'Great Artesian Basin groundwater temperature' (Geoscience Australia dataset, Catalogue No. 76929, available from http://www.ga.gov.au).The grid surfaces 1900-1920, ?, 2000-2010 account for the possible effects of geological faults on groundwater flow in the GAB. Grids 1900-1920_nf and 2000-2010_nf are without the influence of regional tectonic faulting. Null values assigned as 1.000000e+30. Grid cell size (X, Y) = 5000 m, 5000 m. This GIS data set and metadata was produced by CSIRO for the Great Artesian Basin Water Resource Assessment and used in figures 7.2, 7.3 and 7.4 of Ransley TR and Smerdon BD (eds) (2012) Hydrostratigraphy, hydrogeology and system conceptualisation of the Great Artesian Basin. A technical report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia. Projection is Albers equal area conic, with central meridian 143 degrees longitude, standard parallels at -21 and -29 degrees latitude and latitude of projection's origin at -25. For more information, contact: hris Turnadge Research Projects Officer CSIRO Land and Water Waite Road Urrbrae SA 5064

Development of coal mines and coal seam gas (CSG) resources can significantly impact groundwater systems, hydrogeological processes and the surface environment. Consequently, a sound understanding of basin-scale hydrogeology Is critical to developing effective water management strategies. The Australian Government Department of Sustainability, Environment, Water, Population and Communities recently funded investigation of the potential impacts of the development of coal mining and CSG production in several Australian coal basins. The Laura Basin was investigated as part of this program due to the significant environmental and cultural heritage values of the region which include several National Parks and the Great Barrier Reef Marine Park. The Laura Basin is a geological basin on Cape York Peninsula, QLD. There has been relatively limited development of the groundwater resources of the basin to date, which predominantly occur in Mesozoic sandstone units, the Dalrymple Sandstone and the Gilbert River Formation, which are contiguous with the Great Artesian Basin rocks of the Carpentaria Basin.

This document contains metadata for the hydrodynamics products produced by the Great Artesian Basin Water Resource Assessment

Islands in the Pacific region rely heavily on their fresh groundwater, and for a number of islands it is the only reliable source of freshwater throughout the year. Stresses on groundwater resources in many Pacific Island countries are set to escalate in the future with projected population and economic growth. In addition, there are likely to be future climate impacts on groundwater availability and quality. Although a number of studies have been undertaken at a local scale, very limited information is available to consider the impacts of future climates on groundwater systems at a regional scale. This project provides a first-pass regional-scale assessment of the relative potential vulnerability of groundwater to: (i) low rainfall periods and (ii) mean sea-level rise for 15 Pacific Island countries and territories. The dataset associated with this report can be obtained from www.ga.gov.au using title "Pacific Island Groundwater Vulnerability to Future Climates Dataset" or catalogue number 81575.

Boundary of basement inliers penetrating the Great Artesian Basin. These were used to delineate areas of no data in the dataset 'Water table elevation of the Great Artesian Basin' (Geoscience Australia dataset, catalogue #75830). Data is available in Shapefile format This GIS data set was produced for the Great Artesian Basin Water Resource Assessment and used in watertable maps in: Chapter 6 of Ransley TR and Smerdon BD (eds) (2012) Hydrostratigraphy, hydrogeology and system conceptualisation of the Great Artesian Basin. A technical report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia. Regional watertable section of Smerdon BD, Welsh WD and Ransley TR (eds) (2012) Water resource assessment for the Carpentaria region. A report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia, plus Figure 10 in the associated summary report. Regional watertable section of Smerdon BD and Ransley TR (eds) (2012) Water resource assessment for the Central Eromanga region. A report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia, plus Figure 13 in the associated summary report. Regional watertable section of Smerdon BD and Ransley TR (eds) (2012) Water resource assessment for the Surat region. A report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia, plus Figure 14 in the associated summary report. Regional watertable section of Smerdon BD, Welsh WD and Ransley TR (eds) (2012) Water resource assessment for the Western Eromanga region. A report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia, plus Figure 12 in the associated summary report. This dataset and associated metadata can be obtained from www.ga.gov.au, using catalogue number 75841.

Thickness of the Rolling Downs group in the Great Artesian Basin Data is available as a raster in both ESRI grid and ASCII grid formats. This GIS data set was produced for the Great Artesian Basin Water Resource Assessment and used in Figure 5.29 of Ransley TR and Smerdon BD (eds) (2012) Hydrostratigraphy, hydrogeology and system conceptualisation of the Great Artesian Basin. A technical report to the Australian Government from the CSIRO Great Artesian Basin Water Resource Assessment. CSIRO Water for a Healthy Country Flagship, Australia. This dataset and associated metadata can be obtained from www.ga.gov.au, using catalogue number 76540.

Geoscience Australia was recently involved in the reconceptualisation of the hydrogeology of the Great Artesian Basin (GAB), as part of the Great Artesian Basin Water Resource Assessment. The project refined the understanding of key hydrostratigraphic units within the GAB. This brochure describes key aquifers in the GAB and is designed to be distributed with samples from the aquifers. Aquifers covered are the Winton-Mackunda, Cadna-owie-Hooray, Adori Sandstone/Springbok Sandstone, Hutton Sandstone and Precipice Sandstone. Brochure prepared for the International Association of Hydrogeologists Congress 2013, Perth, Australia

Poster prepared for International Association of Hydrogeologists Congress 2013 Sonic drilling is a relatively new technology that was used successfully to obtain relatively uncontaminated and undisturbed continuous core samples with excellent (>99%) recovery rates to depths of 206m in unconsolidated fluvio-lacustrine sediments of the Darling River floodplain. However, there are limitations with the standard sonic coring method. Sands, in particular, are disturbed when they are vibrated out of the core barrel into the flexible plastic sampling tube. There can be changes to moisture content, pore fluid chemistry and sediment mineralogy on exposure to the atmosphere, even when the samples are processed and analysed soon after collection. The option exists during sonic drilling to encapsulate the core in rigid polycarbonate lexan tubes. Although this increases costs and reduces drilling rates, atmospheric exposure of the core during drilling is reduced to the ends of the lexan tubes before being capped. In addition, the tubes can be purged with an inert gas such as argon. Lexan coring is best carried out below the watertable as the heat from drilling dry clays can cause the polycarbonate to melt. In the study, 60 sonic holes (4.5 km) and 40 rotary mud holes (2 km) were obtained as part of a program to map and assess potential groundwater resources and managed aquifer recharge (MAR) targets over a large area (7,500 km2) of the Darling River floodplain. Two of the sonic bores were drilled to depths of 60 metres to obtain lexan-encapsulated core samples. These cores were used to obtain less perturbed samples for pore fluid analysis (salinity, major ions, trace metals, stable isotopes), textural analysis, and analysis of mineral phases to help assess aquifer clogging potential (using XRD, XRF, SEM). An additional advantage of the lexan coring was the recovery of encapsulated and intact sediment intervals for determining porosities, effective porosities, hydraulic conductivities, and other geophysical and petrophysical measurements. By painting some tubes black, sand samples were also successfully obtained for optically stimulated luminescence (OSL) dating. Alternatively, opaque black lexan can be made to order by the supplier. Overall, the superior sample integrity obtained from lexan coring enables a greater range of hydrogeological and hydrochemical parameters to be assessed.

Poster prepared for International Association of Hydrogeologists Congress 2013 In this study, AEM mapping validated by drilling has enabled the lateral extents and thickness of the Pliocene aquifers to be identified. The Pliocene in this area dominantly comprises the fluvial Calivil Formation, with the shallow marine Loxton-Parilla Sands restricted to the southernmost part of the area. Post-depositional warping, tilting and discrete offsets associated with neotoectonics are also recognised. Facies analysis indicates the Calivil was deposited in deep braided streams across a dissected sedimentary landscape. Overall, the sequence is fining-upwards, with evidence for progradation over the Loxton-Parilla. Channel fill materials comprise gravels and sands, and local fine-grained units represent abandoned channels and local floodplain sediments. Integration of textural and hydraulic testing data has revealed there are five hydraulic classes within the Calivil,. At a local scale (10s to 100s of metres), there is considerable lithological heterogeneity, however at a regional scale (kms), sands and gravels are widely distributed with particularly good aquifers developed in palaeochannels and at the confluence of palaeo-river systems. Aquifer testing has revealed Calivil to be an excellent aquifer, with high storage capacity, and locally very high transmissivities (up to 50 l/s). Integration of the AEM data with borehole geophysical data (gamma, induction and NMR) and textural and pore fluid data has enabled maps of aquifer properties including groundwater salinity, porosity, storage and hydraulic conductivity to be derived. Overall, the multi-disciplinary approach adopted has enabled rapid delineation of new groundwater resources, and facilitated assessment of the Pliocene aquifers for managed aquifer recharge.