From 1 - 10 / 95
  • <p>This package contains airborne electromagnetic (AEM) data from the "SkyTEM helicopter EM Howard East region" survey which was flown over Howard East region, Northern Territory during July - August 2017. The area is comprised of 2073.6 line kilometres in total. <p>The aim of the survey is to provide at a reconnaissance scale: <p>a) trends in regolith thickness and variability <p>b) variations in bedrock conductivity <p>c) conductivity of key bedrock (lithology related) conductive units under cover <p>d) the groundwater resource potential of the region <p>This report lists the SkyTEM system information and specifications relevant for this survey, and describes the processing carried out on the data. <p>Geoscience Australia commissioned the survey as part of the Exploring for the Future (EFTF) program. The EFTF program is led by Geoscience Australia (GA), in collaboration with the Geological Surveys of the Northern Territory, Queensland, South Australia and Western Australia, and is investigating the potential mineral, energy and groundwater resources in northern Australia and South Australia. The EFTF is a four-year $100.5 million investment by the Australian Government in driving the next generation of resource discoveries in northern Australia, boosting economic development across this region (https://www.ga.gov.au/eftf).

  • This Central 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. The Mesoproterozoic Musgrave Province is a significant geological feature in Central Australia, covering around 130,000 square kilometres across the tri-border region of Northern Territory, South Australia, and eastern Western Australia. It is characterized by east-west trending, metamorphosed igneous rocks, including granites, intrusions, and volcanics. The province experienced various deformation events, including the Mount West Orogeny and Musgravian Orogeny, resulting in the emplacement of granites and high-grade metamorphism. The Ngaanyatjarra Rift (1090 to 1040 Ma) is a failed intracontinental rift that formed due to magmatism-induced extension. The associated Giles Event was characterised by mafic to ultra-mafic intrusions (Giles Suite), bimodal volcanism and rift sedimentation (Bentley Supergroup), granitic intrusions and dyke emplacement. The Giles Event was followed by the emplacement of dolerite dykes including the Kullal Dyke Suite and the Amata Dolerite, approximately 1000 Ma and 825 Ma. The Peterman Orogeny played a crucial role in shaping the geological architecture of the Musgrave Province, forming the distinctive east-to-west-directed ranges.

  • This Maryborough-Nambour 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 Maryborough Basin is a half-graben intracratonic sag basin mainly filled with Early Cretaceous rocks, overlain by up to 100 m of Cenozoic sediments. It adjoins the older Nambour Basin to the south, comprising Triassic to Jurassic rocks. The boundary between the basins has shifted due to changes in sedimentary unit classifications, with the Cretaceous units now restricted to the Maryborough Basin and Jurassic and older units assigned to the Nambour Basin. Both basins are bounded to the west and unconformably overlies older Permian and Triassic rocks in the Gympie Province and Wandilla Province of the New England Orogen. In the south of the Nambour Basin, it partly overlaps with the Triassic Ipswich Basin. The Nambour Basin in the south is primarily composed of the Nambour Formation, with interbedded conglomerate, sandstone, siltstone, shale, and minor coal. Overlying this is the Landsborough Sandstone, a unit with continental, fluviatile sediments and a thickness of up to 450 m. In the north, the Duckinwilla Group contains the Myrtle Creek Sandstone and the Tiaro Coal Measures, which were formerly considered part of the Maryborough Basin but are now associated with the northern Nambour Basin. In contrast, the Maryborough Basin consists of three main Cretaceous units and an upper Cenozoic unit. The Grahams Creek Formation is the deepest, featuring terrestrial volcanic rocks, volcaniclastic sedimentary rocks, and minor pyroclastic rocks. The overlying Maryborough Formation was deposited in a continental environment with subsequent marine incursion and includes mudstone, siltstone, minor sandstone, limestone, conglomerate, and tuff. The upper Cretaceous unit is the Burrum Coal Measures, comprising interbedded sedimentary rocks deposited in fluvial to deltaic environments. The uppermost unit, the Eocene to Miocene Elliott Formation, includes sandstone, siltstone, conglomerate, and shale deposited in fluvial to deltaic environments. Cenozoic sediments overlying the Elliott Formation consist of Quaternary alluvium, coastal deposits, and sand islands like Fraser Island, influenced by eustatic sea level variations. Volcanic deposits and freshwater sediments also occur in some areas. Adjacent basins, such as the Clarence-Moreton Basin and Capricorn Basin, have stratigraphic correlations with the Maryborough Basin. The Oxley Basin lies to the south, overlying the Ipswich Basin. In summary, the Maryborough Basin and the older Nambour Basin exhibit distinct geological characteristics, with varying rock formations, ages, and sedimentary features, contributing to the diverse landscape of the region.

  • This report presents key results from hydrogeological investigations in the Tennant Creek region, completed as part of Exploring for the Future (EFTF)—an eight year, $225 million Australian Government funded geoscience data and information acquisition program focused on better understanding the potential mineral, energy and groundwater resources across Australia. The EFTF Southern Stuart Corridor (SSC) Project area is located in the Northern Territory and extends in a north–south corridor from Tennant Creek to Alice Springs, encompassing four water control districts and a number of remote communities. Water allocation planning and agricultural expansion in the SSC is limited by a paucity of data and information regarding the volume and extent of groundwater resources and groundwater systems more generally. Geoscience Australia, in partnership with the Northern Territory Department of Environment and Natural Resources and Power and Water Corporation, undertook an extensive program of hydrogeological investigations in the SSC Project area between 2017 and 2019. Data acquisition included; helicopter airborne electromagnetic (AEM) and magnetic data; water bore drilling; ground-based and downhole geophysical data for mapping water content and defining geological formations; hydrochemistry for characterising groundwater systems; and landscape assessment to identify potential managed aquifer recharge (MAR) targets. This report focuses on the Tennant Creek region—part of the Barkly region of the Northern Territory. Investigations in this region utilised existing geological and geophysical data and information, which were applied in the interpretation and integration of AEM and ground-based geophysical data, as well as existing and newly acquired groundwater hydrochemical and isotope data. The AEM and borehole lithological data reveal the highly weathered (decomposed) nature of the geology, which is reflected in the hydrochemistry. These data offer revised parameters, such as lower bulk electrical conductivity values and increased potential aquifer volumes, for improved modelling of local groundwater systems. In many instances the groundwater is shown to be young and of relatively good quality (salinity generally <1000 mg/L total dissolved solids), with evidence that parts of the system are rapidly recharged by large rainfall events. The exception to this is in the Wiso Basin to the west of Tennant Creek. Here lower quality groundwater occurs extensively in the upper 100 m below ground level, but this may sit above potentially potable groundwater and that possibility should be investigated further. Faults are demonstrated to have significantly influenced the occurrence and distribution of weathered rocks and of groundwater, with implications for groundwater storage and movement. Previously unrecognised faults in the existing borefield areas should be investigated for their potential role in compartmentalising groundwater. Additionally a previously unrecognised sub-basin proximal to Tennant Creek may have potential as a groundwater resource or a target for MAR. This study has improved understanding of the quantity and character of existing groundwater resources in the region and identified a managed aquifer recharge target and potential new groundwater resources. The outcomes of the study support informed water management decisions and improved water security for communities; providing a basis for future economic investment and protection of environmental and cultural values in the Tennant Creek and broader Barkly region. Data and information related to the project are summarised in the conclusions of this report and are accessible via the EFTF portal (https://portal.ga.gov.au/).

  • The AEM method measures regolith and rocks' bulk subsurface electrical conductivity, typically to a depth of several hundred meters. AEM survey data is widely used in Australia for mineral exploration (i.e. mapping undercover and detection of mineralisation), groundwater assessment (i.e. hydro-stratigraphy and water quality) and natural resource management (i.e. salinity assessment). Geoscience Australia (GA) has flown Large regional AEM surveys over Northern Australia, including Queensland, Northern Territory and Western Australia. The surveys were flown nominally at 20-kilometre line spacing, using the airborne electromagnetic systems that have signed technical deeds of staging with GA to ensure they can be modelled quantitatively. Geoscience Australia commissioned the survey as part of the Exploring for the Future (EFTF) program. The EFTF program is led by Geoscience Australia (GA), in collaboration with the Geological Surveys of the Northern Territory, Queensland, South Australia and Western Australia, and is investigating the potential mineral, energy and groundwater resources in northern Australia and South Australia. We have used a machine learning modelling approach that establishes predictive relationships between the inverted flight-line modelled conductivity with a suite of national environmental and geological covariates. These covariates include terrain derivatives, gamma-ray radiometric, geological maps, climate derived surfaces and satellite imagery. Conductivity-depth values were derived from a single model using GA's deterministic 1D smooth-30-layer layered-earth-inversion algorithm. (Brodie and Richardson 2015). Three conductivity depth interval predictions are generated to interpolate the actual modelled conductivity data, which is 20km apart. These depth slices include a 0-50cm, 9-11m and 22-27m depth prediction. Each depth interval was modelled and individually optimised using the gradient boosted tree algorithm. The training cross-validation step used label clusters or groups to minimise over-fitting. Many hundreds of conductivity models are generated (i.e. ensemble modelling). Here we use the median of the models as the conductivity prediction and the upper and lower percentiles (95th and 5th) to measure model uncertainty. Grids show conductivity (S/m) in log 10 units. Reported out-of-sample r-squares for each interval in order of increasing depth are 0.74, 0.64, and 0.67. A decline in model performance with increasing depth was expected due to the decrease in suitable covariates at greater depths. Modelled conductivities seem to be consistent with the geological, regolith, geomorphological, and climate processes in the study area. The conductivity grids are at the resolution of the covariates, which have a nominal pixel size of 85 meters. Datasets in this data package include; 1. 0-50cm depth interval 0_50cm_median.tif; 0_50_upper.tif; 0_50_lower.tif 2. 9-11m depth interval 9_11m_median.tif; 9_11m_upper.tif; 9_11m_lower.tif 3. 22-27m depth interval 22_27_median.tif; 22_27_upper.tif; 22_27_lower.tif 4. Covariate shift; Cov_shift.tif (higher values = great shift in covariates) Reference: Ross C Brodie & Murray Richardson (2015) Open Source Software for 1D Airborne Electromagnetic Inversion, ASEG Extended Abstracts, 2015:1, 1-3, DOI: 10.1071/ ASEG2015ab197

  • The Exploring for the Future program Virtual Roadshow was held on 7 July and 14-17 July 2020. The Minerals session of the roadshow was held on 14 July 2020 and consisted of the following presentations: Introduction - Richard Blewett Preamble - Karol Kzarnota Surface & Basins or Cover - Marie-Aude Bonnardot Crust - Kathryn Waltenberg Mantle - Marcus Haynes Zinc on the edge: New insights into sediment-hosted base metals mineral system - David Huston Scale reduction targeting for Iron-Oxide-Copper-Gold in Tennant Creek and Mt Isa - Anthony Schofield and Andrew Clark Economic Fairways and Wrap-up - Karol Czarnota

  • This animation shows how passive seismic surveys Work. It is part of a series of Field Activity Technique Engagement Animations. The target audience are the communities that are impacted by our data acquisition activities. There is no sound or voice over. The 2D animation includes a simplified view of what passive seismic equipment looks like, what the equipment measures and how the survey works.

  • This Daly 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 Daly Basin is a geological formation consisting of Cambrian to Ordovician carbonate and siliciclastic rocks, formed approximately 541 million to 470 million years ago. The basin stretches about 170 km in length and 30 km in width, shaped as a northwest elongated synform with gentle dips of less than 1 degree, likely due to prolonged sedimentary deposition in the shallow seas of the Centralian Superbasin, possibly along basin-scale faults. The primary groundwater reservoir within the Daly Basin is found in the Cambrian Daly River Group. This group comprises three units: the Tindall Limestone, Jinduckin Formation, and Oolloo Dolostone. The Tindall Limestone, which lies at the base, consists of grey, mottled limestone with some maroon-green siltstone or dark grey mudstone. The transition from the Tindall Limestone to the overlying Jinduckin Formation is marked by a shift from limestone to more siliciclastic rocks, indicating a change from open-shelf marine to peri-tidal environments. The Jinduckin Formation, situated above the Tindall Limestone, is composed of maroon-green dolomitic-siliciclastic siltstone with interbeds of dolomitic sandstone-siltstone, as well as dolostone and dolomitic quartz sandstone lenses. It gradually transitions into the carbonate-rich Oolloo Dolostone, with the highest finely laminated dolomitic sandstone-siltstone interbeds at the top of the Jinduckin Formation. The Oolloo Dolostone, the uppermost unit of the Daly River Group, comprises two members: the well-bedded lower Briggs Member, consisting of fine- to medium-grained crystalline dolostone and dolomitic quartz sandstone, and the massive upper King Member. Overlying the Daly River Group is the Ordovician Florina Formation, consisting of three carbonate intervals separated by two fine-grained, glauconite-bearing quartz sandstone units. The Florina Formation and the Daly River Group are covered unconformably by Cretaceous claystone and sandstone of the Carpentaria Basin, which extends over a significant portion of the Daly Basin.

  • This Murray 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 Murray Basin, a significant sedimentary basin in Australia, displays varying sediment thickness across its expanse, with the thickest layers concentrated in its central regions. The basin's geological evolution is characterised by distinct depositional phases. During the Paleocene to Eocene Renmark Group phase, sedimentary deposits encompass fluvial sands at the base, transitioning into paralic carbonaceous clay and lignite layers. These sediments indicate the shift from riverine to shallow marine environments, dating back to the Paleocene and Eocene periods. The Oligocene to Middle Miocene period encompasses the Ettrick Formation and Murray Group Limestone. The former includes marl, and the latter displays glauconitic grey-green marl and bryozoal limestone, revealing prevailing marine conditions during the Oligocene to Middle Miocene. In the Late Miocene to Early Pliocene Bookpurnong Formation, marine shelly dark grey clay and silt, previously known as the Bookpurnong Beds, coexist with Pliocene fluvial to marginal marine quartz sands (Loxton Sands), marking the transition back to terrestrial and nearshore marine settings. During the Late Pliocene to Pleistocene, the Blanchetown Clay, a substantial unit within Lake Bungunnia, signifies lacustrine phases. Overlying ferricretes in the central/eastern basin and the Norwest Bend Formation's oyster coquinas in the western region, the clay exhibits variable coloration and laminations. Lastly, the Pleistocene to Holocene phase witnesses river-induced reworking and erosion of underlying sediments, giving rise to the Shepparton and Coonambidgal formations. In the western Murray Basin, Cenozoic sedimentary rocks are relatively thin, typically measuring under 200-300 meters. The Renmark Trough area presents a maximum thickness of 600 meters.

  • This Carpentaria 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 Carpentaria Basin is a vast intra-cratonic sedimentary basin situated on and offshore in north-eastern Australia, covering around 550,000 square kilometres across Queensland and the Northern Territory. It comprises predominantly sandstone-rich rock units deposited during sea level highs from the Late Jurassic to Mid Cretaceous. The basin overlies a heterogeneous Proterozoic basement and is separated from contemporaneous sedimentary structures by basement highs and inliers. Four main depocentres within the larger Carpentaria Basin form four major sub-basins: the Western Gulf Sub-basin, Staaten Sub-basin, Weipa Sub-basin, and Boomara Sub-basin. While the basin is extensive and continuous in Queensland, it becomes more heterogeneous and discontinuous in the Northern Territory. Remnants of the basin's stratigraphy, referred to as the Dunmarra Basin, are found along the Northern Territory coast and inland. The depositional history commenced during the Jurassic with down warping near Cape York Peninsula, resulting in the Helby beds and Albany Pass beds' concurrent deposition. The basin experienced marine transgressions during the Cretaceous, with the Gilbert River Formation widespread and the Wallumbilla Formation occurring during sea level highs. The Carpentaria Basin's strata are relatively undeformed and unmetamorphosed. The Northern Territory sequence displays slightly different stratigraphy, limited to the height of the Aptian marine transgression above the Georgina Basin. The Walker River Formation and Yirrkala Formation represent key units in this area, outcropping as tablelands and mesas largely unaffected by tectonism.