The Janina 1 borehole was drilled approximately 110 km W of Bourke, New South Wales. The borehole was designed to test aeromagnetic anomalies in the basement rocks and to test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data.

This web service contains sediment and geochemistry data for the Oceanic Shoals Commonwealth Marine Reserve (CMR) in the Timor Sea collected by Geoscience Australia during September and October 2012, on RV Solander (survey GA0339/SOL5650).

Seismic reflection mapping, geochemical analyses and petroleum systems modelling have increased our understanding of the highly prospective Mesoproterozoic and Paleoproterozoic source rocks across northern Australia, expanding the repertoire of exploration targets currently being exploited in Proterozoic petroleum systems. Data collected during the Exploring for the Future program have enabled us to redefine and increase the extent of regional petroleum systems, which will encourage additional interest and exploration activity in frontier regions. Here, we present a review of the Paleoproterozoic McArthur and Mesoproterozoic Urapungan petroleum supersystems, and the most up-to-date interpretation of burial and thermal history modelling in the greater McArthur Basin (including the Beetaloo Sub-basin), South Nicholson Basin and Isa Superbasin. We also present potential direct hydrocarbon indicators imaged in the 2017 South Nicholson Deep Crustal Seismic Survey that increase the attractiveness of this frontier region for hydrocarbon exploration activities. <b>Citation:</b> MacFarlane, S.K., Jarrett, A.J.M., Hall, L.S., Edwards, D., Palu, T.J., Close, D., Troup, A. and Henson, P., 2020. A regional perspective of the Paleo- and Mesoproterozoic petroleum systems of northern 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.

Cratonic margins host many of the natural resources upon which our society depends. Despite this, little is known about the dynamic evolution of these regions and the stability of substantial steps in plate thickness that delineate their boundaries with adjacent mantle. Here, we investigate the spatio-temporal evolution of Australian cratonic lithosphere and underlying asthenospheric mantle by using the geochemical composition of mafic volcanic or shallow intrusive rocks preserved throughout the continent’s history. We have collated a large database of mafic samples that were screened to remove data affected by crystal fractionation or assimilation of cumulate material. We use forward and inverse modelling of igneous trace element compositions to calculate the depth and extent of melting for 28 distinct igneous provinces in the North Australian Craton. These results are used to infer mantle potential temperature and lithospheric thickness at the time of eruption. The majority of Paleoproterozoic magmatic events record high mantle potential temperatures of 1350–1450 °C and relatively low lithospheric thicknesses of ≤50 km. In contrast, younger igneous provinces show a gradual decrease in potential temperature and an increase in lithospheric thickness with time. These constraints on the mantle lay the foundation for the development of a quantitative geodynamic understanding of the evolution of the Australian lithosphere and its resources. <b>Citation:</b> Klöcking, M., Czarnota, K., Champion, D.C., Jaques, A.L. and Davies, D. R., 2020. Mapping the cover in northern Australia: towards a unified national 3D geological model. 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.

Soil geochemistry has been used to discover many mineral deposits in Australia. Further, it places first-order controls on soil fertility in agriculture and can be used to monitor the environment. With this utility in mind, an extensive soil sampling survey was undertaken as part of the Exploring for the Future program across the vast prospective exploration frontier between Tennant Creek and Mount Isa, dubbed the Northern Australia Geochemical Survey (NAGS). In all, 776 stream sediment outlet samples were collected at a depth of 0–10 cm, improving the density of the National Geochemical Survey of Australia by an order of magnitude, to one sample per ~500 km2. Two size fractions from each sample were analysed for a comprehensive suite of chemical elements after total digestion, Mobile Metal Ion™ (MMI) and aqua regia extractions, and fire assay. Here, we highlight the applicability of these results to base metal exploration, evaluation of soil fertility for agriculture and establishment of geochemical baselines. Our results reveal an association between elevated concentrations of commodity or pathfinder elements in the same or downstream catchments as known mineral deposits. Similar features elsewhere suggest new areas with potential for base metal discovery. <b>Citation:</b> Bastrakov, E.N. and Main, P.T., 2020. Northern Australia Geochemical Survey: a review of regional soil geochemical patterns. 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 Congararra 1 borehole was drilled approximately 70 km NNW of Bourke, NSW. The borehole was designed to test aeromagnetic anomalies in the basement rocks, test the electrical conductivity properties of cover and basement rocks to validate airborne electromagnetic (AEM) data, and to test pre-drilling geophysical cover thickness estimates.

Data in the GEOCHEM database comprises inorganic geochemical analytical data and associated metadata. Geochemical data comprises concentration data (value, error, unit of measure) measured on a range of analytical instruments, for a range of elements of the periodic table. Associated metadata includes information on analytical techniques, analytical methodology, laboratory, analysts, date of analysis, detection limits, accuracy, and precision. The GEOCHEM database also records results for reference standards. Data is specifically for rocks, soils and other unconsolidated geological material and does not include oils, gases or water analyses. Geochemical data may be total rock (i.e., whole rock analysed) or for a variety of fractions of the total rock, e.g., various non-total acid digests, mineral separates, differing size fractions. It also includes quantitative to semi-quantitative data from field measurements, such as portable x-ray fluorescence (XRF). It does not include geochemical data for individual minerals. <b>Value: </b>Geochemical data underpins much geoscientific study, and is used directly to classify, characterise and understand geological material and its formation. It has direct relevance to understanding the formation of the earth, the continents, and the processes that create and shape the surface we live on. For example, this information is used within: both discovering and the understanding of mineral deposits we depend on; the nature, health and sustainability of the soils we live and farm on; as well as providing input into a range of potential geohazards. <b>Scope: </b>The collection includes data from over 60 years of Geoscience Australia (GA) and state/territory partner regional geological projects within Australia, as well as continental-scale and regional geochemical surveys like National Geochemical Survey of Australia (NGSA) and Northern Australia Geochemical Survey (NAGS) (Exploring for the Future- EFTF). It also includes data from other countries that GA has worked with, e.g., Papua New Guinea, Antarctica, Solomon Islands and New Zealand. Explore the <b>Geoscience Australia portal - <a href="https://portal.ga.gov.au/">https://portal.ga.gov.au/</a></b>

Preamble -- The 'National Geochemical Survey of Australia: The Geochemical Atlas of Australia' was published in July 2011 along with a digital copy of the NGSA geochemical dataset (doi: 10.11636/Record.2011.020). The NGSA project is described here: www.ga.gov.au/ngsa. The present dataset contains additional geochemical data obtained on NGSA samples: the Plutonium Isotopes Dataset. Abstract -- Seventy three fine-fraction (<75 um) Top Outlet Sediment (TOS, 0 – 10 cm depth) NGSA samples from Queensland were analysed for the plutonium (Pu) isotopes 238Pu and 239+240Pu (unresolved 239Pu and 240Pu) to determine: (1) if Pu is detectable in the Australian environment; and (2) what the levels and ranges of Pu retention in selected Queensland catchment soils are. Radiochemical analyses were performed by alpha spectrometry at the radioanalytical laboratories of Radiation and Nuclear Sciences, Department of Health, Queensland, and at the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA), Victoria. The method yielded a 239+240Pu trace-level detection limit of 0.04 mBq/g (equivalent to 10.4 fg/kg or 0.0056 net counts per minute) with a relative standard deviation (RSD) of 15.1%. The average tracer recovery was 69% (RSD 25%) over a 3-day count. Total analytical uncertainty ranged from 19% to 90% at close to detection limits. Field duplicate repeatability for 239+240Pu activity concentration ranged from 18% to 45%, which in part at least reflects the inherent heterogeneity of soil/sediments containing refractory particles exhibiting variation in Pu activity concentrations. Analytical duplicate repeatability for 239+240Pu activity concentration ranged from 10% to 23%, with the mean activity concentration and error of the replicates reported with propagation of errors. The results show a wide range of 239+240Pu activity concentration in the fine TOS NGSA samples across Queensland (N = 73): 239+240Pu: Min = <0.04 mBq/g; Med ± MAD (median absolute deviation) = 0.09 ± 0.07 mBq/g; Mean ± SD = 0.29 ± 0.72 mBq/g; 95th percentile = 1.53 mBq/g; Max = 4.88 mBq/g. In comparison the world average background is estimated at 0.2 mBq/g. Analytical results for 39% of samples were below detection. Six samples with 239+240Pu > 0.18 mBq/g (70th percentile) were also analysed for 238Pu by the same alpha spectrometry method. Results ranged from 0.04 to 0.1 mBq/g (N = 6). The complete dataset is available to download as a comma separated values (CSV) file from Geoscience Australia's website (https://pid.geoscience.gov.au/dataset/ga/144101).

The Georgina Basin is a Neoproterozoic-Paleozoic basin that spans parts of the Northern Territory and Queensland in northern Australia. The basin is prospective for petroleum, phosphate and base metals (copper, lead and zinc). The Dulcie and Toko synclines in the southern part of the basin are prospective for petroleum, where a thick Cambro-Ordovician succession of marine carbonates hosts several source rocks and associated oil and gas shows. The key source rock units occur within the middle Cambrian Narpa Group including both the Thorntonia Limestone (Series 2 and 3) and the Arthur Creek Formation (Series 3). This presentation provides new geochemical insights into the understanding of the petroleum systems effective in the Dulcie and Toko synclines.

<b>IMPORTANT NOTICE: </b>This web service has been deprecated. The Australian Onshore and Offshore Boreholes OGC service at https://services.ga.gov.au/gis/boreholes/ows should now be used for accessing Geoscience Australia borehole data. This is an Open Geospatial Consortium (OGC) web service providing access to a subset of Australian geoscience samples data held by Geoscience Australia. The subset currently relates specifically to Australian Boreholes.