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 Congararra 2 borehole was drilled approximately 73 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.

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.

The Milcarpa 1 borehole was drilled approximately 9 km SSE of Hungerford, Queensland, adjacent to the road between Hungerford and Wanaaring, 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.

The Tongo 1 borehole was drilled approximately 83 km NE of White Cliffs, 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.

In this Record new U-Pb SHRIMP zircon results are presented from nine samples from western South Australia and eastern Western Australia. This geochronological study was undertaken to provide temporal constraints on the crystalline basement geology beneath the Nullarbor Plain, to assist in geological interpretation of a reflection seismic transect (13GA-EG1) between the Albany-Fraser Province in the west and the central Gawler Craton in the east. This seismic line transects a region in which the crystalline basement geology is entirely buried beneath Neoproterozoic to Cenozoic sedimentary rocks. Consequently, the age, tectonic evolution and mineral potential of the crystalline basement in this region is very poorly understood. The new results complement the very limited pre-existing geochronology data from the Coompana Province and Madura Province, and provide a basis for comparison of geological ages in these provinces with the geological histories reconstructed for the adjacent provinces of the Gawler Craton to the east and the Albany-Fraser Province to the west.

This Record presents new zircon U Pb geochronological data obtained via Sensitive High Resolution Ion Micro Probe (SHRIMP) from rocks sampled within the Wau 1:100 000 map sheet area, which is located on the Papuan Peninsula in eastern Papua New Guinea. Exposure in the Wau Bulolo region comprises low-grade Mesozoic metasedimentary rocks of the Owen Stanley Metamorphics, which are intruded by the mid-Miocene Morobe Granodiorite batholith, and overlain by Pliocene sedimentary and volcanic rocks of the Wau Basin. The map sheet area contains the Morobe Goldfield (from which more than 3.2 Moz of alluvial gold has been mined) and the Hidden Valley epithermal Au-Ag deposit (which has a total gold resource in excess of 3 Moz), and lies about 70 km south-southeast of the giant mid-Miocene Wafi-Golpu porphyry Cu-Au deposit (>26 Moz Au and 9 Mt Cu). The geochronological data in this Record were generated as part of a collaborative project between Geoscience Australia (GA) and the Mineral Resources Authority (MRA) of Papua New Guinea in 2012. Four samples were analysed: two from the Pliocene Bulolo Volcanics and one from the Miocene Morobe Granodiorite to establish precise, accurate magmatic crystallisation ages, and one metasandstone from the Mesozoic Owen Stanley Metamorphics for detrital zircon provenance analysis. Sample locations, descriptions, and U Pb SHRIMP results are summarised in Table 1.1.

This Record presents new zircon U-Pb geochronological data, obtained using a Sensitive High Resolution Ion MicroProbe (SHRIMP) for five samples of plutonic and volcanic rocks from the central Lachlan Orogen and the Thomson Orogen, New South Wales. The work was carried out under the auspices of the National Geoscience Accord, as a component of the collaborative Geochronology Project between the Geological Survey of New South Wales (GSNSW) and Geoscience Australia (GA) during the reporting periods 2011-2012.

This Record presents data collected as part of the ongoing NTGS-GA geochronology project between July 2014 and June 2015 under the National Collaborative Framework (NCF). In total, five new U-Pb SHRIMP zircon and titanite geochronological results derived from four samples from the Arunta Region in the Northern Territory are presented herein (Table 1; Figure 1). Three samples were collected from JERVOIS RANGE in HUCKITTA1 in the eastern Arunta Region, and comprise metasedimentary and metaigneous rocks. The fourth sample analysed is an igneous rock from drillcore in TOBERMOREY.

This Record presents new zircon U-Pb geochronological data, obtained using a Sensitive High Resolution Ion MicroProbe (SHRIMP) for thirty-five samples of plutonic rocks from the New England Orogen, New South Wales. The work was carried out under the auspices of the National Geoscience Accord, as a component of the collaborative Geochronology Project between the Geological Survey of New South Wales (GSNSW) and Geoscience Australia (GA) during the reporting periods 2012-2014.