This web service provides access to groundwater raster products for the Upper Burdekin region, including: inferred relative groundwater recharge potential derived from weightings assigned to qualitative estimates of relative permeability based on mapped soil type and surface geology; Normalised Difference Vegetation Index (NDVI) used to map vegetation with potential access to groundwater in the basalt provinces, and; base surfaces of basalt inferred from sparse available data.

The magnetotelluric (MT) method is increasingly being applied to map tectonic architecture and mineral systems. Under the Exploring for the Future (EFTF) program, Geoscience Australia has invested significantly in the collection of new MT data. The science outputs from these data are underpinned by an open-source data analysis and visualisation software package called MTPy. MTPy started at the University of Adelaide as a means to share academic code among the MT community. Under EFTF, we have applied software engineering best practices to the code base, including adding automated documentation and unit testing, code refactoring, workshop tutorial materials and detailed installation instructions. New functionality has been developed, targeted to support EFTF-related products, and includes data analysis and visualisation. Significant development has focused on modules to work with 3D MT inversions, including capability to export to commonly used software such as Gocad and ArcGIS. This export capability has been particularly important in supporting integration of resistivity models with other EFTF datasets. The increased functionality, and improvements to code quality and usability, have directly supported the EFTF program and assisted with uptake of MTPy among the international MT community. <b>Citation:</b> Kirkby, A.L., Zhang, F., Peacock, J., Hassan, R. and Duan, J., 2020. Development of the open-source MTPy package for magnetotelluric data analysis and visualisation. 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.

We present a resistivity model of the southern Tasmanides of southeastern Australia using Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) data. Modelled lower crustal conductivity anomalies resemble concentric geometries revealed in the upper crust by potential field and passive seismic data. These geometries are a key part of the crustal architecture predicted by the Lachlan Orocline model for the evolution of the southern Tasmanides, in which the Proterozoic Selwyn Block drives oroclinal rotation against the eastern Gondwana margin during the Silurian period. For the first time, we image these structures in three dimensions (3D) and show they persist below the Moho. These include a lower crustal conductor largely following the northern Selwyn Block margin. Spatial association between lower crustal conductors and both Paleozoic to Cenozoic mafic to intermediate alkaline volcanism and gold deposits suggests a genetic association i.e. fluid flow into the lower crust resulting in the deposition of conductive phases such as hydrogen, iron, sulphides and/or graphite. The 3D model resolves a different pattern of conductors in the lithospheric mantle, including northeast trending anomalies in the northern part of the model. Three of these conductors correspond to Cenozoic leucitite volcanoes along the Cosgrove mantle hotspot track which likely map the metasomatised mantle source region of these volcanoes. The northeasterly alignment of the conductors correlates with variations in the lithosphere-asthenosphere boundary (LAB) and the direction of Australian plate movement, and may be related to movement of an irregular LAB topography over the asthenosphere. By revealing the tectonic architecture of a Phanerozoic orogen and the overprint of more recent tectono-magmatic events, our resistivity model enhances our understanding of the lithospheric architecture and geodynamic processes in southeast Australia, demonstrating the ability of magnetotelluric data to image geological processes over time.

The NSW component of the Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP), is a collaboration between Geoscience Australia and the Geological Survey of New South Wales which commenced in 2016. Long-period MT data have been recorded at a 55-km spacing in a rolling deployment which to date has completed 224 of a planned 320 sites in NSW. This article summarises the progress of the AusLAMP NSW program and highlights how it is contributing to our understanding of the tectonic architecture in NSW.

Gold deposits form in a range of geodynamic settings and styles of deposition, associated with specific characteristics in fluid source and chemistry. These differences may lead to differences in the minerals that are deposited in the ascent pathway, and thus alter the physical properties that can be measured at different levels in the lithosphere. Models derived from magnetotelluric data are sensitive to lithospheric resistivity variations and have been increasingly applied to mineral exploration, with evidence emerging for a spatial association between many mineral deposits and lower crustal conductors. Southeastern Australia has estimated resource of ~5000 t gold contained within a variety of deposit styles. A resistivity model of this region was recently published from Australian Lithospheric Architecture Magnetotelluric Project (AusLAMP) data under a collaborative project between Geoscience Australia, the Geological Survey of New South Wales, and the Geological Survey of Victoria. This showed a strong spatial correlation between lower crustal conductors and gold deposits. In this presentation we examine the statistical and geological significance of this correlation for different deposit styles. We demonstrate that there are clear differences in the resistivity expression between different styles of gold deposition. The variability may reflect differences in the fluid source chemistry and geodynamic setting of the deposits, and will have important implications for the exploration of these resources.

Multiple geochronology and isotopic tracer datasets have been compiled at continental scale and visualised in map view. The compiled datasets include Sm-Nd model ages of magmatic rocks; Lu-Hf isotopes from zircon; Pb isotopes from ore-related minerals such as galena and pyrite; U-Pb ages of magmatic, metamorphic and sedimentary rocks; and K-Ar and 40Ar-39Ar ages from minerals and whole rocks. A variety of maps can be derived from these datasets, which we refer to as an Isotopic Atlas of Australia. This ‘atlas’ provides a convenient visual overview of age and isotopic patterns reflecting geological processes that have led to the current configuration of the Australian continent, including progressive development of continental crust from the mantle (Sm-Nd; Lu-Hf), chemical and isotopic evolution in the source regions for mineralising fluids (Pb-Pb), magmatic and high-grade metamorphic reworking of the crust (U-Pb), and cooling and exhumation of the mid-crust (K-Ar; 40Ar-39Ar). These datasets and maps unlock the collective value of several decades of geochronological and isotopic studies conducted across Australia, and provide an important complement to other geological maps and geophysical images—in particular, by adding a time dimension to 2D and 3D maps and models. <b>Citation: </b>Fraser, G.L., Waltenberg,K., Jones, S.L., Champion, D.C., Huston, D.L., Lewis, C.J., Bodorkos, S., Forster, M., Vasegh, D., Ware, B. and Tessalina, S., 2020. An Isotopic Atlas of 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.

The Exploring for the Future Program (EFTF) is a $100.5 million four year, federally funded initiative to better characterise the mineral, energy and groundwater potential of northern Australia. As part of this initiative, this record presents new whole-rock geochemistry data from 967 samples of sedimentary rocks sampled from 26 wells in the South Nicholson region, including the Proterozoic South Nicholson Basin and Lawn Hill Platform, the Neoproterozoic to Devonian Georgina Basin and the Jurassic to Cretaceous Carpenteria Basin. This work complements other components of the EFTF program, including the South Nicholson Basin seismic survey, a comprehensive geochronology program and hydrocarbon prospectivity studies to better understand the geological evolution and basin architecture of the region, and facilitate identification of areas of unrecognised resource potential and prospectivity. The South Nicholson region, straddling north-eastern Northern Territory and north-western Queensland, arguably represents one of the least geologically understood regions of Proterozoic northern Australia. The South Nicholson region is situated between two highly prospective provinces, the greater McArthur Basin in the Northern Territory, the Lawn Hill Platform and the Mount Isa Province in Queensland, both with demonstrated hydrocarbon and base metal potential. These new geochemical data provide baseline understanding of regional resource prospectivity of sedimentary rocks in the South Nicholson region. During 2017 and 2018, 967 drill core and cuttings were sampled from 26 legacy boreholes that intersected the South Nicholson region housed in Northern Territory Geological Survey’s core repository in Darwin, the Geological Survey of Queensland’s core repository in Brisbane and Geoscience Australia’s core repository in Canberra. This data release contains the results of elemental analyses on these samples, which include X-Ray Fluorescence (XRF), Loss-On-Ignition (LOI), Inductively Coupled Plasma-Mass Spectrometry (ICP-MS) for all samples, in addition to ron titration (FeO) for selected samples. The data was generated in the Inorganic Geochemistry laboratory at Geoscience Australia between 2017 and 2019 as part of the EFTF program. All data was quality controlled based on Certified Reference Material standards (CRMs) and duplicate samples analysed with each batch of samples.