The fundamental geological framework of the concealed Paleoproterozoic East Tennant area of northern Australia is very poorly understood, despite its relatively thin veneer of Phanerozoic cover and its position along strike from significant Au–Cu–Bi mineralisation of the Tennant Creek mining district within the outcropping Warramunga Province. We present 18 new U–Pb dates, obtained via Sensitive High Resolution Ion Micro Probe (SHRIMP), constraining the geological evolution of predominantly Paleoproterozoic metasedimentary and igneous rocks intersected by 10 stratigraphic holes drilled in the East Tennant area. The oldest rocks identified in the East Tennant area are two metasedimentary units with maximum depositional ages of ca. 1970 Ma and ca. 1895 Ma respectively, plus ca. 1870 Ma metagranitic gneiss. These units, which are unknown in the nearby Murphy Province and outcropping Warramunga Province, underlie widespread metasedimentary rocks of the Alroy Formation, which yield maximum depositional ages of 1873–1864 Ma. While parts of this unit appear to be correlative with the ca. 1860 Ma Warramunga Formation of the Warramunga Province, our data suggest that the bulk of the Alroy Formation in the East Tennant area is slightly older, reflecting widespread sedimentation at ca. 1870 Ma. Throughout the East Tennant area, the Alroy Formation was intruded by voluminous 1854–1845 Ma granites, contemporaneous with similar felsic magmatism in the outcropping Warramunga Province (Tennant Creek Supersuite) and Murphy Province (Nicholson Granite Complex). In contrast with the outcropping Warramunga Province, supracrustal rocks equivalent to the 1845–1810 Ma Ooradidgee Group are rare in the East Tennant area. Detrital zircon data from younger sedimentary successions corroborate seismic evidence that at least some of the thick sedimentary sequences intersected along the southern margin of the recently defined Brunette Downs rift corridor are possible age equivalents of the ca. 1670–1600 Ma Isa Superbasin. Our new results strengthen ca. 1870–1860 Ma stratigraphic and ca. 1850 Ma tectono-magmatic affinities between the East Tennant area, the Murphy Province, and the mineralised Warramunga Province around Tennant Creek, with important implications for mineral prospectivity of the East Tennant area. Appeared in Precambrian Research Volume 383, December 2022.

Database containing analytical data and interpretations from the Geoscience Geoscience (GA) geochronology program. Includes some legacy methods and externally sourced data. A collection of analytical data to support geochronology data or ages used in other reporting and publications.

The EARTHTIME initiative has enabled improvements in high-precision ID-TIMS U-Pb geochronology, demonstrating SI-traceable calibrations with rigorous uncertainty estimation. In a similar fashion, the LA-ICP-MS U-Pb community have reassessed their uncertainty estimation and workflow to try to harmonise better practice in quantification and interpretation across the community. The SHRIMP community has a current imperative to rewrite its data handling software providing an opportunity to review ion-microprobe U-Pb workflow and uncertainty estimation methods. This work will provide the perfect platform to integrate SHRIMP U-Pb dating practices with more recent data handling approaches to ensure harmony and comparability of output between SHRIMP, LA-ICP-MS and ID-TIMS methods. SHRIMP and LA-ICP-MS data acquisition and processing appear to be very similar. Both methods are relative techniques, requiring calibration to matrix-matched primary reference materials analysed under the same conditions at the same time. Measurement uncertainties are similar, calibration requirements are similar and potential system drift has similar effects and impact on data and concomitant uncertainty estimation. For these and other reasons, we are interrogating SHRIMP and recently published LA-ICP-MS U-Pb data handling workflows to compare approaches, learn mutual lessons, and understand the uncertainty propagation requirements of each method such that a complete understanding of the comparability of U-Pb data obtained by the two methods can be ascertained. We will highlight results to date in describing the SHRIMP and LA-ICP-MS U-Pb data handling workflows in tandem allowing data comparison between the two methods to be properly quantified thereby enabling direct quantification and comparison with ID-TIMS reported ages. In this way, U-Pb geochronology will be a more rigorously applied tool from the highest spatial resolution to highest precision, expanding and building on the EARTHTIME initiative to date. This abstract was submitted to/presented at the 2017 Goldschmidt Conference (https://goldschmidt.info/2017/)

The Thomson Orogen of eastern Australia is a major component of the Tasmanides and has historically been poorly understood and overlooked for exploration due to extensive sedimentary cover including the Eromanga Basin. To further understanding and encourage exploration of this area, Geoscience Australia, the Geological Survey of Queensland and the Geological Survey of New South Wales (NSW) have undertaken a major multidisciplinary geoscientific programme in the southern Thomson Orogen (STO) as a part of the UNCOVER initiative. A major outcome of this project has been the completion of twelve stratigraphic diamond drill holes between 2016 and 2017. SHRIMP U–Pb zircon dating of magmatic and metasedimentary rocks intersected by the boreholes provide new insights into the geological evolution and mineral prospectivity of this region. Geochronology of three intrusive rocks intersected by new boreholes in the NSW part of STO have late Silurian ages of ~425 Ma (Tongo 1), ~421 Ma (Janina 1) and ~421 Ma (Congararra 1). The age of the granodiorite intersected by Tongo 1 is within uncertainty of the intrusion-related Mo-W and later Au-base metal mineralisation at the Cuttaburra and F1 prospects located ~20 km southeast of the Tongo 1 borehole. Additionally, previously unknown volcanic events have been revealed by a dacitic ignimbrite (~387 Ma) in borehole GSQ Eulo 2 (Queensland) and a rhyolite (~395 Ma) in borehole, Milcarpa 1 (NSW). Detrital zircon geochronology has also played an important role in characterising undercover units such as the Werewilka Formation and Nebine Metamorphics, interpreted from geophysical data sets. This abstract was submitted to and presented at the 2018 Australian Geoscience Council Convention (AGCC) (https://www.agcc.org.au/)

This Record presents data collected between March and September 2018 as part of the ongoing Northern Territory Geological Survey–Geoscience Australia (NTGS–GA) SHRIMP geochronology project under the National Collaborative Framework (NCF) agreement and Geoscience Australia's Exploring for the Future Programme. Five new U–Pb SHRIMP zircon geochronological results derived from five samples of meta-igneous and metasedimentary rocks from MOUNT RENNIE (southwestern Aileron Province and northwestern Warumpi Province) in the Northern Territory are presented herein. All five samples are located at or close to the recently discovered greenfield Grapple and Bumblebee prospects that contain precious and base metal sulfide mineralisation. This Record represents the first attempt to provide temporal constraints on the country rocks that host or occur close to this mineralisation. <b>Bibliographic Reference:</b> Kositcin N, McGloin MV, Reno BL and Beyer EE, 2019. Summary of results. Joint NTGS–GA geochronology project: Cu-Au-Ag-Zn mineralisation in MOUNT RENNIE, Aileron and Warumpi provinces, March – September 2018. <i>Northern Territory Geological Survey</i>, <b>Record 2019-011</b>.

This work is a part of an investigation of mineralisation associated with the extensive Kennedy Igneous Association (Champion & Bultitude, 2013) in North Queensland. This part of the project involves U–Pb zircon geochronology of magmatic rocks that are associated with gold mineralisation. By doing this we hope to identify key time-periods of magmatic activity that can be used by explorers to better focus their exploration efforts and assist with the development of new tectono-metallogenic models. Earlier results published by Cross et al. (2019) and Kositcin et al. (2016) in the Jardine Subprovince of the Kennedy Igneous Association in Cape York, for the first time, demonstrated a strong association between gold mineralisation and early Permian (285–280 Ma) felsic dykes that intrude either Proterozoic metamorphic rocks or Devonian granites of the Cape York Batholith. The SHRIMP U–Pb zircon results reported here come from three magmatic rocks, Badu Granite (2678819/QFG8689E), Horn Island Granite (2678820/QFG8800A) and unnamed rhyolite (2678818/QFG8798A), that were sampled from exploration drill core, drilled by Alice Queen Limited on behalf of its subsidiary company, Kauraru Gold Pty Ltd between 2016 and 2017 on the western margins of the historic Horn Island gold mine. Prior to this work, magmatic rocks of the Badu Supersuite on Horn Island were attributed to the Jardine Subprovince of the Kennedy Igneous Association (Champion & Bultitude 2013). The Badu Supersuite comprises the Badu Suite (Badu Granite, Horn Island Granite and unmineralised porphyritic dykes; von Gnielinski et al., 1997) and the Torres Strait Volcanic Group. Gold mineralisation on Horn Island is intrusion-related and occurs within narrow quartz veins that contain native gold and sulphide mineralisation (Alice Queen Limited, 2021) that cut both the Badu and Horn Island granites but not the late-stage porphyritic dykes (von Gnielinski, 1996; von Gnielinski et al., 1997). Historical K–Ar ages from 286–302 Ma for Badu Suite intrusives (Richards and Willmott, 1970) were used to imply a late Carboniferous to early Permian age for the Torres Strait Volcanic Group. Recently however, two units from the Torres Strait Volcanic Group, the Endeavour Strait Ignimbrite and the ‘Bluffs Quarry’ rhyolite dyke yielded SHRIMP 206Pb/238U ages of 349.2 ± 3.1 Ma (Cross et al., 2019) and 353.4 ± 2.2 Ma (Kositcin et al., 2016), respectively, placing this group in the early Carboniferous. Two of the samples, the Badu Granite (2678819/QFG8689E) and Horn Island Granite (2678820/QFG8800A) gave indistinguishable 206Pb/238U results within analytical uncertainty (MSWD = 1.6, POF = 0.21) of 342.8 ± 1.9 Ma and 344.4 ± 1.7 Ma, respectively. The unmineralised, cross cutting, unnamed rhyolite (2678818/QFG8798A) has a significantly younger 206Pb/238U age of 309.9 ± 1.5 Ma. These results demonstrate that the Badu Granite and Horn Island Granite are early Carboniferous in age and not early Permian as previously thought. The historical K–Ar ages (302–286 Ma) for Badu Suite intrusives are interpreted to record thermal resetting. Together with the ca 350 Ma crystallisation ages for two units from the Torres Strait Volcanic Group (Cross et al., 2019; Kositcin et al., 2016), these new results reveal that magmatic crystallisation ages for the Badu Supersuite range between ca 350 Ma and 310 Ma. As such, the Badu Supersuite, along with the Black Cap Diorite (350.7 ± 1.3 Ma; Murgulov et al., 2009) near Georgetown, represents the earliest phase of magmatism associated with the early Carboniferous to late Permian, Kennedy Igneous Association. Consequently, the Badu Supersuite including the Badu Suite and the Torres Strait Volcanic Group are now seen to belong to a newly named Torres Strait Subprovince, which is distinctly older than the Jardine Subprovince on Cape York Peninsula. Additionally, these results constrain the timing of gold mineralisation at Horn Island to between a maximum age at ca 344 Ma provided by the host granites and a minimum age at ca 310 Ma constrained by the rhyolite dyke (2678818/QFG8798A). These constraints for the timing of gold mineralisation at Horn Island are further supported by unpublished results presented by Lisitsin & Dhnaram (2019a, b). These workers mention preliminary ca 342–344 Ma Re–Os molybdenite ages from two samples of quartz-molybdenite veins that cut the Badu Granite and an Ar–Ar age from sericite alteration associated with a quartz-sulphide-gold vein at ca 320 Ma that they considered to best represent the timing of gold mineralisation. The new SHRIMP U–Pb zircon ages presented here for magmatic rocks of the Badu Suite, reveal the association between gold mineralisation and early Carboniferous magmatism associated with the newly named Torres Strait Subprovince of the Kennedy Igneous Association.

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>.

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 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.

<p>This record presents new zircon and titanite U–Pb geochronological data, obtained via Sensitive High Resolution Ion Microprobe (SHRIMP) for twelve samples of plutonic and volcanic rocks from the Lachlan Orogen and the New England Orogen, and two samples of hydrothermal quartz veins from the Cobar region. Many of these new ages improve existing constraints on the timing of mineralisation in New South Wales, as part of an ongoing Geochronology Project (Metals in Time), conducted by the Geological Survey of New South Wales (GSNSW) and Geoscience Australia (GA) under a National Collaborative Framework (NCF) agreement. The results herein (summarised in Table 1.1 and Table 1.2) correspond to zircon and titanite U–Pb SHRIMP analysis undertaken on GSNSW mineral systems projects for the reporting period July 2016–June 2017. Lachlan Orogen <p>The Lachlan Orogen samples reported herein are sourced from operating mines, active prospects, or regions with historical workings. The new dates constrain timing of mineralisation by dating the units which host or crosscut mineralisation, thereby improving understanding of the mineralising systems, and provide stronger constraints for mineralisation models. <p>In the eastern Lachlan Orogen, the new dates of 403.9 ± 2.6 Ma for the Whipstick Monzogranite south of Bega, and 413.3 ± 1.8 Ma for the Banshea Granite north of Goulburn both provide maximum age constraints for the mineralisation they host (Whipstick gold prospect and Ruby Creek silver prospect, respectively). At the Paupong prospect south of Jindabyne, gold mineralisation is cut by a dyke with a magmatic crystallisation age of 430.9 ± 2.1 Ma, establishing a minimum age for the system. <p>The 431.1 ± 1.8 Ma unnamed andesite and the 428.4 ± 1.9 Ma unnamed felsic dyke at the Dobroyde prospect 10 km north of Junee are just barely distinguishable in age, in the order that is supported by field relationships. The andesite is the same age as the c. 432 Ma Junawarra Volcanics but has different geochemical composition, and is younger than the c. 437 Ma Gidginbung Volcanics. The two unnamed units pre-date mineralisation, and are consistent with Pb-dating indicating a Tabberaberran age for mineralisation at the Dobroyde gold deposit. <p>Similarly, the 430.5 ± 3.4 Ma leucogranite from Hickory Hill prospect (north of Albury) clarifies that this unit originally logged as Jindera Granite (since dated at 403.4 ± 2.6 Ma) is instead affiliated with the nearby Mount Royal Granite, which has implications for the extent of mineralisation hosted within this unit. <p>Cobar Basin <p>Titanite ages of 382.5 ± 2.6 Ma and 383.4 ± 2.9 Ma from hydrothermal quartz veins that crosscut and postdate the main phase of mineralisation at the Hera mine in the Cobar region constrain the minimum age for mineralisation. These ages are indistinguishable from a muscovite age of 381.9 ± 2.2 Ma interpreted to be related to late- or post-Tabberaberan deformation event, and these results indicate that mineralisation occurred at or prior to this deformation event. <p>New England Orogen <p>The new ages from granites of the New England Orogen presented in this record aid in classification of these plutons into various Suites and Supersuites, and these new or confirmed relationships are described in detail in Bryant (2017). Many of these plutons host mineralisation, so the new ages also provide maximum age constraints in the timing of that mineralisation. <p>The 256.1 ± 1.3 Ma age of the Deepwater Syenogranite 40 km north of Glen Innes indicates that it is coeval with the 256.4 ± 1.6 Ma (Black, 2006) Arranmor Ignimbrite Member (Emmaville Volcanics) that it intrudes, demonstrating that both intrusive and extrusive magmatism was occurring in the Deepwater region at the same time. The 252.0 ± 1.2 Ma age for the Black Snake Creek Granite northeast of Tenterfield is consistent with its intrusive relationship with the Dundee Rhyodacite (254.34 ± 0.34 Ma; Brownlow et al., 2010). Similarly, the 251.2 ± 1.3 Ma age for the Malara Quartz Monzodiorite southeast of Tenterfield is consistent with field relationships that demonstrate that it intrudes the Drake Volcanics (265.3 ± 1.4 Ma–264.4 ± 2.5 Ma, Cross and Blevin, 2010; Waltenberg et al., 2016). <p>The 246.7 ± 1.5 Ma Cullens Creek Granite north of Drake was dated in an attempt to provide a stronger age constraint on mineral deposits that also cut the Rivertree and Koreelan Creek plutons (249.1 ± 1.3 Ma and 246.3 ± 1.4 Ma respectively, Chisholm et al., 2014a). However, the new age is indistinguishable from the Koreelan Creek Granodiorite, and timing of mineralisation is not further constrained, but the new age demonstrates a temporal association between the Cullens Creek and Koreelan Creek plutons. <p>The 239.1 ± 1.2 Ma age for the Mann River Leucogranite west of Grafton is indistinguishable in age from plutons in the Dandahra Suite and supports its inclusion in this grouping. The new age also constrains the timing of the distal part of the Dalmorton Gold Field, and implies that the gold vein system postdates the Hunter-Bowen orogeny. <p>The 232.7 ± 1.0 Ma Botumburra Range Monzogranite east of Armidale is younger than most southern New England granites, but this age is very consistent with the Coastal Granite Association (CGA), and the new age, along with the previously noted petrographic similarities (Leitch and McDougall, 1979) supports incorporation of the Botumburra Range Monzogranite into the Carrai Supersuite of the CGA (Bryant, 2017).