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  • We collected 38 groundwater and two surface water samples in the semi-arid Lake Woods region of the Northern Territory to better understand the hydrogeochemistry of this system, which straddles the Wiso, Tennant Creek and Georgina geological regions. Lake Woods is presently a losing waterbody feeding the underlying groundwater system. The main aquifers comprise mainly carbonate (limestone and dolostone), siliciclastic (sandstone and siltstone) and evaporitic units. The water composition was determined in terms of bulk properties (pH, electrical conductivity, temperature, dissolved oxygen, redox potential), 40 major, minor and trace elements as well as six isotopes (δ18Owater, δ2Hwater, δ13CDIC, δ34SSO4=, δ18OSO4=, 87Sr/86Sr). The groundwater is recharged through infiltration in the catchment from monsoonal rainfall (annual average rainfall ~600 mm) and runoff. It evolves geochemically mainly through evapotranspiration and water–mineral interaction (dissolution of carbonates, silicates, and to a lesser extent sulfates). The two surface waters (one from the main creek feeding the lake, the other from the lake itself) are extraordinarily enriched in 18O and 2H isotopes (δ18O of +10.9 and +16.4 ‰ VSMOW, and δ2H of +41 and +93 ‰ VSMOW, respectively), which is interpreted to reflect evaporation during the dry season (annual average evaporation ~3000 mm) under low humidity conditions (annual average relative humidity ~40 %). This interpretation is supported by modelling results. The potassium (K) relative enrichment (K/Cl mass ratio over 50 times that of sea water) is similar to that observed in salt-lake systems worldwide that are prospective for potash resources. Potassium enrichment is believed to derive partly from dust during atmospheric transport/deposition, but mostly from weathering of K-silicates in the aquifer materials (and possibly underlying formations). Further studies of Australian salt-lake systems are required to reach evidence-based conclusions on their mineral potential for potash, lithium, boron and other low-temperature mineral system commodities such as uranium. <b>Citation:</b> P. de Caritat, E. N. Bastrakov, S. Jaireth, P. M. English, J. D. A. Clarke, T. P. Mernagh, A. S. Wygralak, H. E. Dulfer & J. Trafford (2019) Groundwater geochemistry, hydrogeology and potash mineral potential of the Lake Woods region, Northern Territory, Australia, <i>Australian Journal of Earth Sciences</i>, 66:3, 411-430, DOI: 10.1080/08120099.2018.1543208

  • The purpose of this Record is to document the written material issued at the Groundwater School held 29 March - 9 April 1965 in Adelaide. Record 1965/85 deals with the organisation, syllabus, and general scope of the School and it is not necessary to repeat these aspects in this record. The material is issued in two parts: Part 1: Hydrogeology, Geophysics, Hydraulics, and Pumping Tests. Part 2: Drilling, Bore Construction, Chemistry of Groundwater, Utilisation. No attempt was made to edit the material which was written by the lecturer in most cases as lecture notes and not for publication.

  • Poster describing how GA made the WASANT palaeovalley map (GEOCAT #73980).

  • The potential for geochemical reactions to cause aquifer clogging or detrimental water quality changes was assessed for a managed aquifer recharge (MAR) target in the Darling River floodplain. The assessment used ambient groundwater quality from the target Calivil Formation aquifer, as well as from the shallow unconfined aquifers; Darling River source water quality; and mineralogy and geochemistry of sonic-cored aquifer samples. PHREEQC was used to examine the impact of mixing and interaction between these end-members. There is considerable variability in the redox state within the Calivil aquifer, with groundwater pe values ranging from -6 to 8. PHREEQC simulations using the median pe value of 3 resulted in super-saturation with respect to Fe(OH)3 . Hence, injection of an oxygenated source water into anoxic zones within the target aquifer can result in iron clogging due to precipitation of any source water dissolved iron and any Fe(II) oxidation in the sediments (in pyrite or displaced from exchange sites). The amount of Fe(II) within the storage zone available to be oxidised is unknown and may be limited given that Fe(III) oxides were present in the core material. The aquifer material contains species that may be released during MAR, including aluminium, arsenic, fluoride, iron, manganese, molybdenum, nickel, selenium and uranium. Injection of source water with elevated dissolved organic carbon (DOC) could enhance metal and metalloid release through reductive dissolution of iron oxides within the storage zone. The fate of any mobilised trace species would be dictated by storage zone redox conditions. Arsenic and molybdenum are likely to be adsorbed to any iron oxide surfaces under oxic conditions. Uranium and selenium are likely to reprecipitate in anoxic zones. This provides the opportunity for natural treatment within the storage zone to control mobilised trace metal species.

  • Legacy product - no abstract available

  • 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 Lindsay-Wallpolla 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 Group's 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.

  • Report on operational activities with data, analysis and interpretation for the Gawler - Eucla demonstration study site in South Australia