From 1 - 10 / 166
  • The presence of Neogene fault systems can have a significant impact on hydraulic connectivity of aquifers, juxtaposing otherwise disconnected aquifers, enhancing recharge and/or discharge or acting as barriers to flow and consequently compartmentalising groundwater resources. Previously, regional airborne electromagnetics (AEM) transects allied with groundwater investigations have pointed to the potential for localised compartmentalisation of the Daly River Basin groundwater systems. However, existing data is sparse, and equivocal. In this context, the main aim of the Daly River Basin Project is to determine if compartmentalisation of the aquifers is a significant factor and thus should be explicitly considered in groundwater modelling and water allocation planning. The objectives of the project main goals of the project are to: (1) map Neogene faults through the use of airborne electromagnetic (AEM) and morphotectonic mapping, and (2) assess the permeability and transmissivity of mapped fault zones and their role in potential groundwater system compartmentalisation. Data acquisition includes 3325 line-kilometres of new AEM and airborne magnetics, ground (ground magnetic resonance (GMR)), and borehole geophysics, drilling, groundwater sampling and hydrochemical analysis, geomorphic and morphotectonics mapping. Hydrogeophysical, geomorphic and hydrogeological data will also be used to better understand groundwater-surface water connectivity and the potential for managed aquifer recharge schemes to replenish extracted groundwater resources. The outcomes of this project will inform decisions on water allocations and underpin effective and efficient groundwater use. This paper specifically reports on the ability of AEM and morphotectonics mapping to identify Neogene fault systems in the Daly River Basin.

  • The Western Davenport region has been identified as an area of interest for future agricultural development. However, realisation of this potential depends on access to a reliable supply of groundwater, underpinned by rigorous geological and groundwater information. A three-dimensional stratigraphic model has been created for the Western Davenport area of the Southern Stuart Corridor project under the Exploring for the Future program. Our interpretation integrates airborne electromagnetic data with historical drillhole and outcrop data to improve geological and hydrogeological understanding. Results show that stratigraphies of the Wiso and Georgina basins are equivalent and laterally continuous in this area. This enables a more complete hydrostratigraphy to be defined and underpins improved hydrogeological conceptualisation. New hydrochemical data support the conceptual model that the aquifers of the Wiso and Georgina basins are interconnected at a regional scale. The initial assessment of water quality indicates that groundwater may support further agricultural development. Analysis of new water chemistry data has improved understanding of groundwater processes and potential areas of recharge. This work will inform management decisions to enhance the economic and social opportunities in the Western Davenport area, while protecting the environmental and cultural value of water resources. <b>Citation:</b> Northey, J.E., Clark, A.D., Smith, M.L. and Hostetler, S., 2020. Delineation of geology and groundwater resources in a frontier region: Western Davenport, Northern Territory. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • This Galilee Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. This Galilee Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Galilee Basin is a large intracratonic sedimentary basin in central Queensland. The basin contains a variably thick sequence of Late Carboniferous to Middle Triassic clastic sedimentary rocks dominated by laterally extensive sandstone, mudstone and coal. These rocks were mostly deposited in non-marine environments (rivers, swamps and lakes), although there is minor evidence for marginal marine settings such as deltas and estuaries. Sedimentation did not occur continuously across the approximately 90 million year history of basin development, and intervals of episodic compression, uplift and erosion were marked by distinct depositional breaks. Over much of the surface area of the Galilee Basin the main aquifers targeted for groundwater extraction occur in the younger rocks and sediments that overlie the deeper sequence of the Galilee Basin. The primary aquifers that supply groundwater in this region are those of the Eromanga Basin, as well as more localised deposits of Cenozoic alluvium. However, in the central-east and north-east of the Galilee Basin, the Carboniferous to Triassic rocks occur at or close to surface and several aquifer units supply significant volumes of groundwater to support pastoral and town water supplies, as well as being the water source for several spring complexes. The three main groundwater systems identified in the Galilee Basin occur in the 1. Clematis Group aquifer, 2. partial aquifer of the upper Permian coal measures (including the Betts Creek beds and Colinlea Sandstone), and 3. aquifers of the basal Joe Joe Group. The main hydrogeological units that confine regional groundwater flow in the Galilee Basin are (from upper- to lower-most) the Moolayember Formation, Rewan Formation, Jochmus Formation and Jericho Formation. However, some bores may tap local groundwater resources within these regional aquitards in areas where they outcrop or occur close to surface. Such areas of localised partial aquifer potential may be due in part to enhanced groundwater storage due to weathering and fracturing.

  • Groundwater is an essential part of Darwin’s water supply mix, and is sourced from Howard East Borefield (HEB) and McMinns Borefield in the Koolpinyah Dolostone Aquifer (KDA), east of Darwin. Previous work suggested that electrical conductivity anomalies observed in airborne electromagnetic (AEM) data within 8 km of HEB may be caused by saline groundwater within the KDA that is separated from HEB by geological features that effectively compartmentalise the aquifer. Nevertheless, concerns grew that increased groundwater use may result in migration of saline groundwater towards HEB, which could compromise the groundwater resource. We collected hydrochemistry, including isotopes, time-series groundwater salinity and AEM data to better understand the complexities of the KDA. These data are presented here, along with a hydrodynamic analysis undertaken by the Northern Territory Department of Environment and Natural Resources, which shows that drawdown is occurring more rapidly from the NE of HEB and that dykes ~8 km NE of HEB act as barriers to groundwater flow. We show that groundwater sampled on the NE side of these dykes has a seawater composition. We use new AEM data to map the elevation of the top of unweathered dyke material and to characterise AEM conductors proximal to HEB. Our mapping reveals that the top of the unweathered portion of these dykes is commonly below sea level. We also show that AEM conductors proximal to HEB are more likely mineralised clays than saline groundwater within the aquifer. Drilling is required to confirm these results. Our findings contribute to building a robust conceptual understanding of the KDA and will inform future modelling of the groundwater system. <b>Citation:</b> Haiblen, A.M., Symington, N.J., Woltmann, M.J., Ray, A., Gow, L.J., Leplastrier, A. and McGrath, E.S.B., 2020. A multifaceted approach to investigating hydrogeological complexities in the Koolpinyah Dolostone Aquifer, Howard East, Northern Territory. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • Geoscience Australia and its predecessors have analysed the hydrochemistry of water sampled from bores, surface features, rainwater and core samples (pore water). Samples have been collected during drilling or monitoring projects, including Exploring for the Future (EFTF). The hydrochemistry database includes physical-chemical parameters (EC, pH, redox potential, dissolved oxygen), major and minor ions, trace elements, isotopes and nutrients. The resource is accessible via the Geoscience Australia Portal <a href="https://portal.ga.gov.au/">(https://portal.ga.gov.au/)</a>

  • The Exploring for the Future Southern Stuart Corridor Groundwater Project undertook extensive multidisciplinary geoscientific investigations across four study areas and six Indigenous communities in central Australia to better understand and characterise groundwater resources. The project was developed to support improvements in water resilience for communities and future agricultural developments in the region. Geoscience Australia collected 9800 line kilometres of airborne electromagnetic data, drilled and installed 15 new monitoring bores, acquired 78 surface nuclear magnetic resonance soundings, recorded downhole geophysical data and groundwater level measurements from >50 bores, and completed hydrochemical analysis of 75 samples. Integration of these datasets provided insights into recharge areas and rates, and potential for managed aquifer recharge. The project also improved our understanding of the geological systems hosting groundwater and interconnections between systems. Potential new groundwater supplies, enhanced understanding of groundwater processes and improved geological models will assist water agencies to better manage groundwater resources across the region. <b>Citation:</b> Hostetler, S., Slatter, E., McPherson, A.A., Tan, K.P., McInnes, D. J., Wischusen, J.D.H. and Ellis, J.H., 2020. A multidisciplinary geoscientific approach to support water resilience in communities in Central Australia. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • Publicly available groundwater data have been compiled to provide a common information base to inform environmental, resource development and regulatory decisions in the Adavale Basin region. This web service summarises salinity and water levels for the Adavale Basin located within the Adavale Basin region.

  • Salinity of groundwater directly affects its suitability for different uses, including human consumption, stock water, agricultural use, and mineral or energy extraction. Traditionally, direct measurements of groundwater salinity at monitoring bores that intersect an aquifer have been used to map the spatial distribution of groundwater salinity. However, drilling is a logistically and economically challenging task, and we are usually left with a sparse set of measurements from which to infer groundwater salinity over large spatial extents. Airborne electromagnetic (AEM) sounding provides a solution to this problem. This is because AEM can be flown rapidly and cost-effectively over large swathes of land, and high subsurface bulk conductivities inferred from the AEM are well correlated with groundwater salinity in porous aquifers. We present here a methodology and case study from the Keep River Plains in the Northern Territory that provides information for land and watershed managers about the confidence with which salinity can be mapped over large areas using AEM. Extensive pore fluid sampling of the saturated zone, which lies beneath the watertable, enables this workflow to be used effectively. The results provided by our method can feed into decision making while accounting for uncertainty, enabling remote communities to manage their land and water resources effectively. <b>Citation:</b> Symington, N.,Ray, A., Harris-Pascal, C., Tan, K.P., Ley-Cooper, A.Y., and Brodie, R.C., 2020. Groundwater salinity estimation using borehole and AEM data: a framework for uncertainty analysis. In: Czarnota, K., Roach, I., Abbott, S., Haynes, M., Kositcin, N., Ray, A. and Slatter, E. (eds.) Exploring for the Future: Extended Abstracts, Geoscience Australia, Canberra, 1–4.

  • This Laura Basin dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. The Laura Basin contains sedimentary rocks deposited between 168 and 102 million years ago during the Middle Jurassic to Early Cretaceous. The basin extends offshore beneath the Great Barrier Reef, and forms a bowl-shaped geologic feature. The strata have a maximum thickness of about 1,000 m in the north-central part of the onshore basin. Three main stratigraphic units comprise the stratigraphic succession of the Laura Basin, these being the Rolling Downs Group (Late Aptian to Albian, Cretaceous), the Gilbert River Formation (Lower Cretaceous to Jurassic) and the Dalrymple Sandstone (Upper to Middle Jurassic). The Rolling Downs Group was deposited in a shallow marine environment and has a basal shale unit (the Wallumbilla Formation) with minor siltstone and conglomerate bands overlain by marine silty and sandy claystone. The Gilbert River Formation was deposited in lagoonal to marginal marine environments and is dominated by clay-rich sandstone that is locally glauconitic and interbedded with minor calcareous siltstone, claystone and conglomerate. The Dalrymple Sandstone was deposited in lagoonal and fluvial environments and is dominated by sandstone with lesser claystone, siltstone, conglomerate, tuff and coal. The Laura Basin overlies older rocks of the Permian to Triassic Lakefield Basin, which extends northwards into surrounding marine waters, the Paleozoic metasedimentary rocks of the Hodgkinson region, associated with the Mossman Orogen, and Proterozoic basement rocks.

  • This South-east Australian Fractured Rock Province dataset contains descriptive attribute information for the areas bounded by the relevant spatial groundwater feature in the associated Hydrogeology Index map. Descriptive topics are grouped into the following themes: Location and administration; Demographics; Physical geography; Surface water; Geology; Hydrogeology; Groundwater; Groundwater management and use; Environment; Land use and industry types; and Scientific stimulus. Groundwater in Australia's fractured rock aquifers is stored in fractures, joints, bedding planes, and cavities within the rock mass, comprising about 40% of the country's groundwater. Much of this water can be utilized for irrigation, town water supplies, stock watering, and domestic use, based on state regulations. Fractured systems account for approximately 33% of all bores in Australia but contribute to only 10% of total extraction due to variable groundwater yield. Quantifying groundwater movement in fractured rock systems is challenging, as it depends on the distribution of major fractures. Groundwater flow direction is more influenced by the orientation of fractures than hydraulic head distribution. Recharge in fractured rock aquifers is typically localized and intermediate. In Eastern Australia, New South Wales' Lachlan Orogen, which extends from central and eastern New South Wales to Victoria and Tasmania, is a significant region with diverse lithological units, including deep marine turbidites, shallow marine to sub-areal sediments, extensive granite bodies, and volcano-intrusive complexes. This region contains various mineral deposits, such as orogenic gold, volcanic-hosted massive sulphide, sediment-hosted Cu-Au, porphyry Au-Cu, and granite-related Sn. Note: The study does not include additional Orogens in the east (New England) and west (Thomson and Delamerian). The Delamerian Orogen is present throughout western Tasmania.