Newer version v1.1 available at eCat <a href="https://pid.geoscience.gov.au/dataset/ga/147720">147720</a> Isotopic data from rocks and minerals have the potential to yield unique insights into the composition and evolution of the Earth's crust and mantle. Time-integrated records of crust and mantle differentiation (as preserved by the U-Pb, Sm-Nd and Lu-Hf isotopic systems, for example) are important in a wide range of geological applications, especially when successfully integrated with other geological, geophysical, and geochemical datasets. However, such integration requires (i) compilation of comprehensive isotopic data coverages, (ii) unification of datasets in a consistent structure to facilitate inter-comparison, and (iii) easy public accessibility of the compiled and unified datasets in spatial and tabular formats useful and useable by a broad range of industry, government and academic users. This constitutes a considerable challenge, because although a wealth of isotopic information has been collected from the Australian continent over the last 40 years, the published record is fragmentary, and derived from numerous and disparate sources. Unlocking and harnessing the collective value of isotopic datasets will enable more comprehensive and powerful interpretations, and significantly broaden their applicability to Earth evolution studies and mineral exploration. As part of the Exploring for the Future (EFTF) program (https://www.ga.gov.au/eftf), we have designed a new database structure and web service system to store and deliver full Lu-Hf isotope and associated O-isotope datasets, spanning new data collected during research programs conducted by Geoscience Australia (GA), as well as compiled literature data. Our approach emphasises the links between isotopic measurements and their spatial, geological, and data provenance information in order to support the widest possible range of uses. In particular, we build and store comprehensive links to the original sources of isotopic data so that (i) users can easily track down additional context and interpretation of datasets, and (ii) generators of isotopic data are appropriately acknowledged for their contributions. This system delivers complete datasets including (i) full analytical and derived data as published by the original author, (ii) additional, normalised derived data recalculated specifically to maximise inter-comparability of data from disparate sources, (iii) metadata related to the analytical setup, (iv) a broad range of sample information including sampling location, rock type, geological province and stratigraphic unit information, and (v) descriptions of (and links to) source publications. The data is delivered through the Geoscience Australia web portal (www.portal.ga.gov.au), and can also be accessed through any web portal capable of consuming Open Geospatial Consortium (OGC)-compliant web services, or any GIS system capable of consuming Web Map Services (WMS) or Web Feature Services (WFS). This Record describes the database system and web service tables. It also contains full tabulated datasets for data compiled from the North Australian Craton as part of the EFTF program. These data are predominantly micro-analytical zircon analyses which are linked at the spot-level across Lu-Hf, O, and U-Pb measurements. This data release comprises 5974 individual analyses from 149 unique rock samples.

This report presents the results of an elemental and carbon and oxygen isotope chemostratigraphy study on three historic wells; Kidson-1, Willara-1 and Samphire Marsh-1, from the southern Canning Basin, Western Australia. The objective of this study was to correlate the Early to Middle Ordovician sections of the three wells to each other and to wells with existing elemental and carbonate carbon isotope chemostratigraphy data from the Broome Platform, Kidson and Willara sub-basins, and the recently drilled and fully cored stratigraphic Waukarlycarly 1 well from the Waukarlycarly Embayment.

<div>Geoscience Australia’s Exploring for the Future (EFTF) program provides precompetitive information to inform decision-making by government, community and industry on the sustainable development of Australia's mineral, energy and groundwater resources. By gathering, analysing and interpreting new and existing precompetitive geoscience data and knowledge, we are building a national picture of Australia’s geology and resource potential. This leads to a strong economy, resilient society and sustainable environment for the benefit of all Australians. This includes supporting Australia’s transition to net zero emissions, strong, sustainable resources and agriculture sectors, and economic opportunities and social benefits for Australia’s regional and remote communities. The EFTF program, which commenced in 2016, is an eight year, $225m investment by the Australian Government.</div><div>The onshore Canning Basin in Western Australia was the focus of a regional hydrocarbon prospectivity assessment undertaken by the EFTF program dedicated to increasing investment in resource exploration in northern Australia, with the objective being to acquire new data and information about the potential mineral, energy and groundwater resources concealed beneath the surface. As part of this program, significant work has been carried out to deliver pre-competitive data in the region including new seismic acquisition, drilling of a stratigraphic well, and geochemical analysis from historic exploration wells.</div><div>As part of this program, a compilation of the compound-specific isotopic compositions of crude oils from 30 petroleum wells in the Canning Basin have been completed. The samples were analysed in Geoscience Australia’s Isotope and Organic Geochemistry Laboratory and the collated results are released in this report. This report provides additional stable carbon and hydrogen isotopic data to build on the oil-oil correlations previously established by Edwards and Zumberge (2005) and Edwards et al. (2013). This information can be used in future geological programs to determine the origin of the crude oils, and hence increase our understanding of the Larapintine Petroleum Supersystem, as established by Bradshaw (1993) and Bradshaw et al. (1994).</div><div><br></div>

<div>A groundwater chemistry, regolith chemistry and metadata record for legacy geochemical studies over the southern Curnamona Province done by GA and partners as part of CRC LEME from 1999 to 2005, that was never fully released. This includes comprehensive groundwater chemistry from more than 250 bores in the Broken Hill region, containing physicochemical parameters, major and trace elements, and a suite of isotopes (34S, Pb, Sr, 18O, D). Recent work on this dataset (in 2021) has added hydrostratigraphic information for these groundwater samples. Also included is a regolith geochemistry dataset collected adjacent to some of the groundwater bores which tests the geochemical response of a range of different size fractions, depths and digests.</div>

The Australian Government’s $225 million Exploring for the Future (EFTF) program is committed to supporting a strong economy, resilient society and sustainable environment for the benefit of Australians (https://www.ga.gov.au/eftf). At its heart, the program is about stimulating industry now to ensure a sustainable, long-term future for Australia through an improved understanding of the nation’s minerals, energy and groundwater resource potential. By gathering and analysing geological and geophysical data and making the results publicly available, the program supports regional development and informed decision making across Australia, resulting in jobs and growth. The Energy component of this program is designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of onshore basins and attract exploration investment to Australia. As part of the EFTF Natural Hydrogen module, molecular and isotopic analyses were undertaken by Geoscience Australia on natural gas samples from the wells Canunda 2 and Ralgnal 1 from the southwestern margin of the Patchawarra Trough in the Cooper Basin, with the raw data from these analyses being released in this report. Some data from these wells were included in the nationwide studies of helium and hydrogen, as published by Boreham et al. (2018; 2021), and build on previous studies that document the composition of Australian natural gases (Boreham et al., 2001). These data are available through the Geoscience Australia portal at https://portal.ga.gov.au/

This Record presents 40Ar/39Ar chronologic results acquired in support of collaborative regional geoscientific investigations and mapping programs conducted by Geoscience Australia (GA) and the Northern Territory Geological Survey (NTGS). Argon isotopic data and interpretations from hornblende, muscovite, and biotite from seven samples collected from the Aileron Province in ALCOOTA , HUCKITTA, HALE RIVER, and ILLOGWA CREEK in the Northern Territory are presented herein. The results complement pre-existing geochronological constraints from U–Pb zircon and monazite analyses of the same or related samples, and provide new constraints on the thermal and deformation history of the Aileron Province. Three samples (2003082017, 2003082021, 2003083040) were taken from ALCOOTA in the northeastern portion of the Aileron Province. Biotite in sample 2003082017 from the ca 1.81 Ga Crooked Hole Granite records cooling below 320–280°C at 441 ± 5 Ma. Biotite in sample 2003082021 from the ca 1.73 Ga Jamaica Granite records cooling below 320–280°C at or after 414 ± 2 Ma. Muscovite in sample 2003083040 from the Delny Metamorphics, which were deposited after ca 1.82 Ga and preserve evidence for metamorphism at ca 1.72 Ga and 1.69 Ga, records cooling below 430–390°C at 399 ± 2 Ma. The fabrics preserved in the samples from the Crooked Hole Granite and Delny Metamorphics are interpreted to have formed due to dynamic metamorphism related to movement on the Waite River Shear Zone, an extension of the Delny Shear Zone, during the Palaeoproterozoic. Portions of the northeastern Aileron Province are unconformably overlain by the Neoproterozoic–Cambrian Georgina Basin, indicating these samples were likely at or near the surface by the Neoproterozoic. Together, these data indicate that rocks of the Aileron Province in ALCOOTA were subjected to heating above ~400°C during the Palaeozoic. Two samples (2003087859K, 2003087862F) of exoskarn from an indeterminate unit were taken from drillhole MDDH4 in the Molyhil tungsten–molybdenum deposit in central HUCKITTA. The rocks hosting the Molyhil tungsten–molybdenum deposit are interpreted as ca 1.79 Ga Deep Bore Metamorphics and ca 1.80 Ga Yam Gneiss. They experienced long-lived metamorphism during the Palaeoproterozoic, with supersolidus metamorphism observed until at least ca 1.72 Ga. Hornblende from sample 2003087859K indicates cooling below 520–480°C by 1702 ± 5 Ma and may closely approximate timing of skarn-related mineralisation at the Molyhil deposit; hornblende from sample 2003087862F records a phase of fluid flow at the Molyhil deposit at 1660 ± 4 Ma. The Salthole Gneiss has a granitic protolith that was emplaced at ca 1.79 Ga, and experienced alteration at ca 1.77 Ga. Muscovite from sample 2010080001 of Salthole Gneiss from the Illogwa Shear Zone in ILLOGWA CREEK records cooling of the sample below ~430–390°C at 327 ± 2 Ma. This may reflect the timing of movement of, or fluid flux along, the Illogwa Shear Zone. An unnamed quartzite in the Casey Inlier in HALE RIVER has a zircon U–Pb maximum depositional age of ca 1.24 Ga. Muscovite from sample HA05IRS071 of this unnamed quartzite yields an age of 1072 ± 8 Ma, which likely approximates, or closely post-dates, the timing of deformation in this sample; it provides the first direct evidence for a Mesoproterozoic episode of deformation in this part of the Aileron Province.

<div>The first ca. 2.2 billion years of Earth history saw significant change; from a water-world dominated by an anoxic atmosphere and tonalitic continents, to the exposed landmasses, oxygenated atmosphere, and granitic crust of the Paleoproterozoic. Precisely when, and how, these major changes occurred, remain some of the most important and controversial questions in modern geoscience. Here, we present an extensive new zircon U-Pb-Hf-O isotopic and trace element dataset from Earth’s largest preserved Archean continent, the Superior Craton, Canada. These data record a number of fundamental geochemical changes through time and indicate a major geological and geodynamic transition occurred toward the end of Archean, at ca. 2.7 Ga. Our data show that, at&nbsp;&gt;2704–2695&nbsp;Ma, the southern Superior Craton had juvenile εHf, light to mantle-like δ18O, low (Eu/Eu*)/Y (drier/shallower crust), reduced ΔFMQ, less continental initial-U (Ui)/Yb, and more mantle-like Ui/Nb. At ca. 2704–2695&nbsp;Ma, there is a marked transition in multiple datasets, including increases in δ18O, (Eu/Eu*)/Y, ΔFMQ, Ui/Yb and Ui/Nb data, together with more distinct arc-like trace element trends. These data reveal that at 2.7 Ga there was an increase in: (1) continental surface weathering, supported by increased sedimentation at &lt;2.68 Ga, (2) oxidized and hydrous magmatism, and (3) surface material in magma sources. Together, these observations suggest a major geodynamic transition from ‘vertical’ tectonics (sagduction, drips) to north-dipping subduction at 2.7 Ga. The increase in δ18O suggests that proximal continental crust, probably in the northern Superior Craton, became emergent at this time, an inference supported by detrital zircon geochronology. Hence, this dataset links major geodynamic change to the emergence of continental crust and the rise of more oxidized magmatism. These fundamental changes to the Earth’s surface environment, tectonics, and atmosphere at 2.7 Ga, provide evidence for an Earth systems turning-point at the end of the Neoarchean.</div> This Abstract was submitted/presented to the 2022 Specialist Group in Geochemistry, Mineralogy and Petrology (SGGMP) Conference 7-11 November (https://gsasggmp.wixsite.com/home/biennial-conference-2021)

The accessory mineral zircon is the most widely used geological timekeeper and tracer of crustal growth processes. Specifically, U-Pb isotopes in zircon offer a means to accurately determine the timing of magmatic events and their Hf isotopic composition provides a means to constrain magma source composition and potentially approximate source age. The high spatial resolution provided by in situ techniques such as secondary ion mass spectrometry (SIMS) and laser ablation inductively coupled mass spectrometry (LA-ICP-MS) have the advantage of being able to target different growth zones within individual zircon crystals, and unravel complex magmatic histories. However, utilising this power effectively requires calculation of accurate initial Hf compositions, which are founded on the assumption that the information obtained via the U-Pb and Lu-Hf systems are correctly integrated. A typical Hf isotope LA-ICP-MS analysis ablates a sample volume that is two orders of magnitude greater than a typical SIMS analysis. Thus, when age determination has been carried out by SIMS it is necessary to demonstrate that each subsequent Hf isotope analysis has sampled a similar isotopically homogeneous volume. Here, we use a combined SIMS and laser ablation split stream (LASS)-ICP-MS approach, whereby U-Pb isotopic measurement concurrently on the same sample volume as the Hf isotope measurement is compared to prior lower volume SIMS measurements. Using a suite of new drill core magmatic rock samples from the comparatively unexplored Coompana Province in South Australia, we demonstrate how such an approach can be used to filter Hf isotope datasets by identifying LA-ICP-MS analyses that sampled mixtures of different zircon growth domains. The robust initial 176Hf/177Hf compositions obtained from the filtered Coompana data set indicate that the province represents part of a juvenile Paleoproterozoic-Mesoproterozoic arc system formed through hyperextension of the margin of the Archean Gawler Craton, which can be correlated to the Musgrave Province and Madura Province in central and western Australia respectively. This hyperextension process is temporally similar to that on the now-adjacent Archean Yilgarn Craton margin.

<div>Exploring for the Future (EFTF) is a program dedicated to exploring Australia’s resource potential and boosting investment. This program is designed to produce pre-competitive information to assist with the evaluation of the hydrocarbon resource potential of onshore basins and attract exploration investment to Australia. This record presents geochemical analyses of natural gases sampled from Nangwarry 1, located in the onshore Otway Basin, undertaken in partnership with the Department for Energy and Mining – Energy Resources, Government of South Australia, as part of the EFTF program Natural Hydrogen module. The Nangwarry Joint Venture drilled Nangwarry 1 to investigate the potential for the development of food grade, carbon dioxide production from this well. The results of the molecular and stable carbon and hydrogen isotopic analyses undertaken by Geoscience Australia are released in this report. The molecular data show that the gas composition in this well has an average of 96 mol% CO2 with an isotopic signature indicative of a magmatic origin, being comparable with previously produced gases from onshore Otway Basin wells (e.g. Boggy Creek 1, Caroline 1) for use by the food industry. The carbon and hydrogen isotopic composition of the C1–C5 hydrocarbon gases from Nangwarry 1 are suggestive of a source from within the Crayfish Supersequence.</div>

<div>At the 2021 AESC (Australian Earth Sciences Convention), Geoscience Australia (GA) introduced a continental-scale Isotopic Atlas of Australia (Fraser et al., 2020) through an interactive poster display (Fraser et al., 2021). In the two years since, progress on this Isotopic Atlas has continued and expanded datasets are now publicly available and downloadable via Geoscience Australia’s Exploring for the Future (EFTF) Geochronology and Isotopes Data Portal.</div><div><br></div><div>This poster provides example maps produced from the compiled data of multiple geochronology and isotopic tracer datasets, now available in the Geochronology and Isotopes Data Portal. Available data include Sm–Nd model ages of magmatic rocks (Champion et al., 2013); Lu–Hf isotopes from zircon and associated O-isotope data (Waltenberg et al., 2023); Pb–Pb isotopes from ore-related minerals such as galena and pyrite (Huston et al., 2019); Rb–Sr stable isotopes from surface regolith (de Caritat et al., 2022, 2023); U–Pb interpreted ages of magmatic, metamorphic and sedimentary rocks (Jones et al., 2018); and K–Ar, Ar–Ar, Re–Os, Rb–Sr and fission-track interpreted ages from minerals and whole rocks.</div><div><br></div><div>Significant recent additions to the datasets include geochronology compilations for Victoria (Waltenberg et al., 2021) and Tasmania (Jones et al., 2022) and full geochronology analytical data tables for GA’s SHRIMP (Sensitive High Resolution Ion Micro Probe) U–Pb results. The online data portal provides tools for visualizing data in commonly-used diagrammatic formats (e.g. Time-Space style plots for geochronology, isotope evolution diagrams for Nd and Hf data). Data are also available for download in a range of formats (CSV, JSON, KML, Shapefile) to allow manipulation and visualization offline for specific purposes.</div><div><br></div><div>Work is ongoing to improve the coverage of legacy interpreted ages geochronology data, to include geochronology analytical data tables for both ID-TIMS and LA-ICP-MS data, and to update the Sm-Nd and Pb-Pb in ores coverages with new data. New work is in progress to develop a Pb-Pb isotopic coverage from representative ‘basement’ rocks (Liebmann et al., 2022) and to expand the coverage of oxygen and Lu-Hf isotopes from zircon, with a current focus in south-eastern Australia (Mole et al., 2022).</div><div><br></div><div>This Isotopic Atlas of Australia 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. 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.</div> Abstract/Poster submitted and presented at 2023 Australian Earth Science Convention (AESC), Perth WA (https://2023.aegc.com.au/)