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.

The Hera Au–Pb–Zn–Ag deposit in the southeastern Cobar Basin of central New South Wales preserves calc-silicate veins/skarn and remnant carbonate/sandstone-hosted skarn within a reduced anchizonal Siluro-Devonian turbidite sequence. The skarn orebody distribution is controlled by a long-lived, basin margin fault system, that has intersected a sedimentary horizon dominated by siliciclastic turbidite, with lesser gritstone and thick sandstone intervals, and rare carbonate-bearing stratigraphy. Foliation (S1) envelopes the orebody and is crosscut by a series of late-stage east–west and north–south trending faults. Skarn at Hera displays mineralogical zonation along strike, from southern spessartine–grossular–biotite–actinolite-rich associations, to central diopside-rich–zoisite–actinolite/tremolite–grossular-bearing associations, through to the northern most tremolite–anorthite-rich (garnet-absent) association in remnant carbonate-rich lithologies and sandstone horizons; the northern lodes also display zonation down dip to garnet present associations at depth. High-T skarn assemblages are pervasively retrogressed to actinolite/tremolite–biotite-rich skarn and this retrograde phase is associated with the main pulse of sulfide mineralisation. The dominant sulfides are high-Fe-Mn sphalerite–galena–non-magnetic high-Fe pyrrhotite–chalcopyrite; pyrite, arsenopyrite and scheelite are locally abundant. The distribution of metals in part mimics the changing gangue mineralogy, with Au concentrated in the southern and lower northern lode systems and broadly inverse concentrations for Ag–Pb–Zn. Stable isotope data (O–H–S) from skarn amphiboles and associated sulfides are consistent with magmatic/basinal water and magmatic sulfur inputs, while hydrosilicates and sulfides from the wall rocks display elevated δD and mixed δ34S consistent with progressive mixing or dilution of original basinal/magmatic waters within the Hera deposit by unexchanged waters typical of low latitude (tropical) meteoritic waters. High precision titanite (U–Pb) and biotite (Ar–Ar) geochronology reveals a manifold orebody commencing with high-T skarn and retrograde Pb–Zn-rich skarn formation at ≥403 Ma, Au–low-Fe sphalerite mineralisation at 403.4 ± 1.1 Ma, foliation development remobilisation or new mineralisation at 390 ± 0.2 Ma followed by thrusting, orebody dismemberment at (384.8 ± 1.1 Ma) and remobilization or new mineralisation at 381.0 ± 2.2 Ma. The polymetallic nature of the Hera orebody is a result of multiple mineralizing events during extension and compression and involving both magmatic and likely basinal fluid/metal sources. <b>Citation:</b> Fitzherbert, Joel A., McKinnon, Adam R., Blevin, Phillip L., Waltenberg, Kathryn., Downes, Peter M., Wall, Corey., Matchan, Erin., Huang Huiqin., The Hera orebody: A complex distal (Au–Zn–Pb–Ag–Cu) skarn in the Cobar Basin of central New South Wales, Australia <i>Resource Geology,</i> Vol 71, Iss 4, pp296-319 <b>2021</b>. DOI: https://doi.org/10.1111/rge.12262

The late Permian Wandsworth Volcanic Group (WVG) in the southern New England Orogen (SNEO) is dominated by a monotonous series of amalgamated rhyodacitic to felsic eruptives, with minor interbedded flows, intrusives and sediments. The area enclosing known exposures of the WVG cover more than 30,000 km2, with a minimum thickness of 2 km. The top of the succession, as well as the vast majority of the pile representing non-welded material, has not been preserved. Field relationships indicate a broadly contemporaneous (though not necessarily genetic) relationship with late Permian granite magmatism, while Triassic plutons (typically in the range 246-243 Ma) intrude the WVG. SHRIMP U-Pb zircon dating indicates ages around 256.4 ± 1.6 Ma for basal units of the WVG, and 254.1 ± 2.2 Ma for the youngest preserved member of the WVG (Dundee Rhyodacite), defining a short period of substantial intermediate to acid eruptive volcanism. The compositionally unevolved Drake Volcanics to the northeast are older (264.4 ± 2.5 Ma) while those at Halls Peak are older still (Early Permian). Granites of the I-type Moonbi and Uralla Supersuites are dominantly 256-251 Ma and thus overlap in timing (and space) with the WVG event. Interestingly, many mineralized leucogranites (e.g. Parlour Mountain, Oban River, Gilgai) which were formerly regarded as Triassic are now established as synchronous with the Moonbi and Uralla Supersuites and the WVG. The age range of eruption of the WVG permitted by the SHRIMP results (~6 Ma) has been further constrained by CA-ID-TIMS U-Pb zircon analysis which yielded oldest and youngest ages of 255.54 ± 0.16 Ma and 253.26 ± 0.15 Ma respectively, indicating a maximum eruptive time range of ~2 Ma for the preserved pile. Our new results coincide with those determined from CA-ID-TIMS dating of tuffs in the Sydney and Gunnedah Basins. WVG exposures at Attunga are exactly (within ~0.1 Ma) coincident with the age of tuffs within the Trinkey Formation located in the Gunnedah Basin to the west, and the Dundee Rhyodacite is similarly closely matched to the thick Awaba Tuff in the Sydney Basin. Notably, much of the late Permian volcanic and plutonic magmatism in the SNEO is restricted to a remarkably small time range, which coincides exactly with the range of ash fall events in the Sydney and Gunnedah Basins, and possibly further afield. This suggests the SNEO, and the WVG in particular, was the dominant source of volcanic material erupted into these adjacent basins. Further, the adjacent basins may provide a more complete record of Permo-Triassic magmatism in the SNEO than currently preserved within the orogen itself.

This web service provides access to the Geoscience Australia (GA) ISOTOPE database containing compiled age and isotopic data from a range of published and unpublished (GA and non-GA) sources. The web service includes point layers (WFS, WMS, WMTS) with age and isotopic attribute information from the ISOTOPE database, and raster layers (WMS, WMTS, WCS) comprising the Isotopic Atlas grids which are interpolations of the point located age and isotope data in the ISOTOPE database.

This Record presents new U-Pb geochronological data, obtained via Sensitive High Resolution Ion Micro Probe (SHRIMP), from six samples of igneous rocks and four samples of sedimentary rocks, collected from south-central New South Wales. The work is part of an ongoing Geochronology Project, conducted by the Geological Survey of New South Wales (GSNSW) and Geoscience Australia (GA) under a National Collaborative Framework (NCF) agreement, to better understand the geological evolution of the central Lachlan Orogen in the East Riverina region. The results presented herein correspond to the reporting period July 2015-June 2016.

<p>The Mesoproterozoic Roper Group of the McArthur Basin has excellent petroleum potential, but its poorly constrained post-depositional history has hampered resource exploration and management. The Derim Derim Dolerite occupies an important position in the regional event chronology, having intruded the Roper Group prior to deformation associated with the ‘Post-Roper Inversion’ event. It was assigned a magmatic crystallisation age of 1324 ± 4 Ma (uncertainties are 95% confidence unless otherwise indicated) in 1997, based on unpublished Sensitive High Resolution Ion Micro Probe (SHRIMP) U-Pb analyses of dolerite-hosted baddeleyite from sample 97106010, collected from the Derim Derim Dolerite type locality in outcrop within the northwestern McArthur Basin. Herein, we refine these data via Isotope Dilution-Thermal Ionisation Mass Spectrometry (ID-TIMS) analysis of baddeleyites plucked from the SHRIMP grain-mounts, which yielded a precise mean 207Pb/206Pb date of 1327.5 ± 0.6 Ma. This date is significantly older than a baddeleyite U-Pb ID-TIMS date of 1313.8 ± 1.3 Ma recently obtained from dolerite ALT-05, sampled in Pacific Oil and Gas Ltd drillhole Altree 2, near the northern margin of the Beetaloo Sub-basin, and 200 km south of 97106010. This pair of results indicates that Derim Derim Dolerite magmatism spanned at least 10-15 Ma. Previously documented geochemical variation in Mesoproterozoic mafic rocks across the Northern Territory (such as the 1325 ± 36 Ma (2σ) Galiwinku Dolerite in the northern McArthur Basin, 1316 ± 40 Ma phonolites intruding the eastern Pine Creek Orogen, and 1295 ± 14 Ma gabbro in the Tomkinson Province) may reflect episodic pulses of magmatism hitherto obscured by the low precision of the available isotopic dates. <p><b>Citation:</b> Bodorkos, S., Yang, B., Collins, A.S., Crowley, J., Denyszyn, S.W., Claoue-Long, J.C., Anderson, J.R. and Magee, C., 2020 Precise U–Pb baddeleyite dating of the Derim Derim Dolerite: evidence for episodic mafic magmatism in the greater McArthur Basin. 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.

This web service provides access to the Geoscience Australia (GA) ISOTOPE database containing compiled age and isotopic data from a range of published and unpublished (GA and non-GA) sources. The web service includes point layers (WFS, WMS, WMTS) with age and isotopic attribute information from the ISOTOPE database, and raster layers (WMS, WMTS, WCS) comprising the Isotopic Atlas grids which are interpolations of the point located age and isotope data in the ISOTOPE database.

<div>This Record documents the efforts of Geoscience Australia (GA) in compiling a New South Wales (NSW) Uranium–Lead (U–Pb) geochronology interpreted age compilation (version 1.0), utilising the MinView data from the Geological Survey of New South Wales (GSNSW), GA’s ‘in house’ storage of SHRIMP (Sensitive High Resolution Ion Micro Probe) ages, and other disparate publication sources e.g. academic journal articles and university theses. Here we describe both the dataset itself and the process by which it is incorporated into the continental-scale Isotopic Atlas of Australia. This initial release of the NSW geochronology compilation comprises of 1007 U–Pb ages of named and unnamed rock units in NSW.&nbsp;</div><div><br></div><div>The Isotopic Atlas draws together age and isotopic data from across the country and provides visualisations and tools to enable non-experts to extract maximum value from these datasets. Data is added to the Isotopic Atlas in a staged approach with priorities determined by GA- and partner-driven focus regions and research questions. This NSW U–Pb compilation represents the third in a series of compilation publications (Records and Datasets) for the southern states of Australia, which are a foundation for the second phase of the Exploring for the Future initiative over the period 2020–2024. All geochronology compilations in this series of Isotopic Atlas of Australia Records are available online from the Geochronology and Isotopes Data Portal.</div><div><br></div>

<div>This Queensland Geological Record presents ten new Sensitive High Resolution Ion MicroProbe (SHRIMP) U–Pb zircon and monazite results obtained under the auspices of the Geological Survey of Queensland–Geoscience Australia (GSQ–GA) National Collaborative Framework (NCF) geochronology project between July 2017 and June 2018. These data were collected in support of ongoing regional mapping and geoscientific programs led by the GSQ in the Mount Isa region.&nbsp;</div><div><br></div><div><br></div><div><br></div><div><br></div><div><strong>Bibliographic reference:</strong></div><div>Kositcin, N., Lewis, C. J. Withnall, I. W., Slade, A. P., Sargent, S. and Hutton, L. J. 2023. Summary of results. Joint GSQ–GA Geochronology Project: Mount Isa region, 2017–2018. GSQ Record 2023/03. Geoscience Australia, Canberra. Record 2023/32, Geological Survey of Queensland. http://dx.doi.org/10.26186/147793</div>

Geoscience Australia’s Exploring for the Future 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 Exploring for the Future program, which commenced in 2016, is an eight year, $225m investment by the Australian Government. This Record presents new U-Pb zircon geochronology from the Loch-Lilly Kars and Lake Wintlow (as described by Clark et al. 2024) Belts of the central Delamerian Orogen (Foden et al., 2020; Gilmore et al., 2023; Mole et al., 2023), performed on Geoscience Australia’s (GA) sensitive high-resolution ion microprobe (SHRIMP). The eight samples presented here (three sedimentary and five igneous rocks; Table i) were collected during Geoscience Australia’s drilling campaign across the region, which consisted of 17 drill-holes (Pitt et al., 2023), using two drilling techniques (coiled-tube rotary and conventional diamond). This work was performed as part of the MinEx CRC National Drilling initiative (NDI) and Geoscience Australia’s Darling-Curnamona-Delamerian project of the Exploring for the Future program (EFTF; <a href="https://www.eftf.ga.gov.au/">https://www.eftf.ga.gov.au/</a>). The primary aims of this drilling were to (1) understand and constrain the geology of the southern Loch-Lilly Kars Belt; and (2) assess whether Cambrian magmatic rocks continued to the south-west in the Lake Wintlow Belt, marking a possible continuation of the Stavely Belt volcanic arc rocks observed in western Victoria (Bowman et al., 2019; Lewis et al., 2016; Lewis et al., 2015; Schofield, 2018; Figure i). As both these regions are covered, this new drilling and the geochronology they allow provide the first constraints on the age of these rock units. In addition, due to the lack of surface correlation and detailed geological mapping, these units currently have no officially-defined stratigraphic nomenclature and remain unnamed. For detailed information on all drill-holes completed as part of the survey, we direct readers to the summary report by Pitt et al. (2023): <a href="https://ecat.ga.gov.au/geonetwork/srv/eng/catalog.search#/metadata/148639">eCat 148639</a>.