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 Record contains new zircon U-Pb geochronological data, obtained via Sensitive High-Resolution Ion Micro Probe (SHRIMP), from two samples of metamorphosed felsic igneous rocks of the Proterozoic Pinjarra Orogen (Western Australia), intersected in diamond drillcore at the base of deep petroleum exploration wells penetrating the Paleozoic sedimentary successions of the Perth Basin. In the southern Perth Basin, petroleum exploration well Sue 1 was terminated at depth 3074.2 m, in crystalline basement rocks of the southern Pinjarra Orogen. Abundant zircon from a biotite-bearing felsic orthogneiss at depth 3073.2-3073.7 m yielded a complex array of U-Pb isotopic data, indicative of significant post-crystallisation disturbance of the isotopic system. A Discordia regression fitted to the array yielded an upper intercept date of 1076 ± 35 Ma (all quoted uncertainties are 95% confidence intervals unless specified otherwise) interpreted to represent magmatic crystallisation of the igneous precursor to the orthogneiss, and a lower intercept date of 680 ± 110 Ma which is our best estimate of the age of the tectonothermal event responsible for post-crystallisation disturbance of the U-Pb system. Crust of known Mesoproterozoic age is rare in the southern Pinjarra Orogen: pre-1000 Ma igneous crystallisation ages in the Leeuwin Complex were previously known only from two c. 1090 Ma garnet-bearing orthogneisses at Redgate Beach (Nelson, 1999), 30 km west of Sue 1. All other dated outcrops have revealed Neoproterozoic (780-680 Ma) granitic protoliths reworked by Early Cambrian (540-520 Ma) magmatism, deformation and metamorphism (Nelson, 1996, 2002; Collins, 2003). In the northern Perth Basin, petroleum exploration well Beagle Ridge 10A was terminated at depth 1482 m, in crystalline basement rocks of the northern Pinjarra Orogen. A leucocratic orthogneiss sampled within the interval 1464.0-1467.0 m yielded only sparse zircon, but four of the seven grains analysed yielded a weighted mean 207Pb/206Pb date of 1092 ± 27 Ma, interpreted to represent magmatic crystallisation of the igneous precursor to the orthogneiss. Our data show no evidence for Neoproterozoic U-Pb resetting of the c. 1090 Ma zircons: where present, post-crystallisation isotopic disturbance is predominantly geologically recent. The two newly dated samples are located at opposite ends of the Perth Basin (about 470 km apart), and although the two magmatic crystallisation ages are imprecise, the date of 1092 ± 27 Ma from the Beagle Ridge 10A leucocratic orthogneiss is indistinguishable from the date of 1076 ± 35 Ma from the Sue 1 felsic orthogneiss. Furthermore, both rocks contain inherited zircon of Mesoproterozoic age (1620-1180 Ma in Sue 1; 1290-1210 Ma in Beagle Ridge 10A), indicating the presence of pre-1100 Ma crustal components in their parent magmas. This is consistent with a suite of Paleoproterozoic Sm-Nd model ages determined by Fletcher et al. (1985) on buried Pinjarra Orogen orthogneisses, which span 2.01 ± 0.06 Ga to 1.78 ± 0.04 Ga in the north (near BMR Beagle Ridge 10A), and including a model age of 1.80 ± 0.04 Ga from a sample of granitic gneiss obtained from Sue 1. Fletcher et al. (1985) argued that the consistency of 2.1-1.8 Ga Nd model ages obtained from crystalline basement in drillcore beneath the southern and northern Perth Basin, and from outcrop in the Northampton Complex and Mullingarra Complex of the northern Pinjarra Orogen, indicated a similar or shared crustal evolution. Our new U-Pb zircon data support this model, expanding the known extent of 1100-1050 Ma felsic magmatism in both the southern and northern Pinjarra Orogen, and indicating that Neoproterozoic tectonothermal overprinting appears to be restricted to the Leeuwin Complex, with no corresponding event discernible in the northern Pinjarra Orogen.

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/)

Zircon U-Pb ages, εHf(t) and δ18O isotopic data, geochemistry and limited Sm-Nd results mostly from deep basement drill cores from undercover parts of the Thomson Orogen, provide strong temporal links with outcropping regions of the orogen as well as important clues for its evolution and relationship with the Lachlan Orogen. SHRIMP U–Pb ages from three Early Ordovician volcanic samples and one granite from the undercover, Thomson Orogen shows that magmatism of this age is widespread across the central, undercover regions of the orogen and occurred in a narrow time-window between 480 Ma and 470 Ma. These rocks have evolved, εHf(t)zrn (-6.26 to -12.18), εNd (-7.1 to -11.3), and supracrustal δ18Ozrn (7.01–8.50‰) which is in stark contrast to the Early Ordovician rocks in the Lachlan Orogen, that are isotopically juvenile. Two samples have latest Silurian to earliest Devonian ages (1586685 DIO Ella 1; 425.4 ± 6.6 Ma and 2122055 Hungerford Granite; 419.1 ± 2.5) and coincide with a major period of intrusive magmatism in the southern Thomson and the Eastern and Central Lachlan Orogen. These samples have evolved εHf(t)zrn (-4.62 to -6.42) and supracrustal δ18Ozrn (9.26–10.29‰) which is similar to Lachlan Orogen rocks emplaced during this time. Four samples have mid Early to early Late Devonian ages (408–382 Ma) and appear to have been emplaced in a generally extensional tectonic regime. Two of these are from the Gumbardo Formation (1682891 PPC Carlow 1 and 1682892 PPC Gumbardo 1), the basal unit of the Adavale Basin, and constrain its opening to between 408 Ma and 403 Ma. The other two samples (1585223 AAE Towerhill 1 and 2122056 Currawinya Granite) have ages of ca. 382 Ma. These latter samples generally show a shift towards more juvenile εHf(t)zrn and mantle-like δ18Ozrn values, a trend that is also seen in rocks of this age in the Lachlan Orogen. Collectively, zircon Hf and O isotopes show that magmatism in the central, undercover part of the Thomson Orogen was initially derived from isotopically evolved magma sources but progressed to more juvenile sources during the Devonian. Furthermore, it appears that samples from the Thomson Orogen may fall along two distinct Hf-O isotopic mixing trends. One trend, appears to have incorporated an older (more evolved) supracrustal component and occurs in the northern two-thirds of the Thomson Orogen, while the other trend is generally less evolved and occurs in the southern third of the Thomson Orogen and is geographically continuous with the Lachlan Orogen. <b>Citation:</b> A. J. Cross, D. J. Purdy, D. C. Champion, D. D. Brown, C. Siégel & R. A. Armstrong (2018) Insights into the evolution of the Thomson Orogen from geochronology, geochemistry, and zircon isotopic studies of magmatic rocks, <i>Australian Journal of Earth Sciences</i>, 65:7-8, 987-1008, DOI: 10.1080/08120099.2018.1515791

The Australian Resource Reviews are periodic national assessments of individual mineral commodities. The reviews include evaluations of short-term and long-term trends for each mineral resource, world rankings, production data, significant exploration results and an overview of mining industry developments.

<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).

This Record presents new Sensitive High Resolution Ion Microprobe (SHRIMP) U–Pb geochronological results for samples collected from the Mary Kathleen Domain, which forms the western part of the Eastern Fold Belt in the Mount Isa Inlier. Eight samples, comprising three granites, one quartz diorite, two metarhyolites, one feldspathic quartzite, and one of matrix material from a breccia, have been analysed as part of ongoing investigations by GSQ in collaboration with researchers from James Cook University. The results enable a better understanding of the evolution of the domain, the associated magmatism, and any related mineralisation. <b>Bibliographic Reference:</b> Kositcin, N., Bultitude, R.J., and Purdy, D.J. Summary of Results. Joint GSQ–GA Geochronology Project: Mary Kathleen Domain, Mount Isa Inlier, 2018–2019. <i>Queensland Geological Record</i><b> 2019/02</b>.

An important finding of this study is the presence of Williams-Naraku Batholith ages (i.e. ca 1500 Ma) east and (well) north of the currently known extent. Sample 2804770/DPMI013 is a leucocratic biotite granite collected from unnamed unit PLg/k ca 30 km southwest of Burke and Wills Roadhouse at the far northern outcropping extent of the Mary Kathleen Domain. This unit intrudes the Corella Formation and Boomarra Metamorphics as small pods and dykes that likely represent the upper portions of a larger pluton. The results from this sample are complex but indicate a minimum crystallisation age of 1500 ± 6 Ma. This is within error of units assigned to the Williams and Naraku Batholiths (e.g. Mavis Granodiorite, Malakoff Granite, Wimberu Granite – see geochronology compilation of Jones et al., 2018). A similar but more certain age of 1511 ± 4 Ma was determined for an unnamed amphibole granite farther south near Kajabbi (2804772/DPMI049b). It is likely that this intrusion also represents the upper parts of a pluton that is more extensive at depth. Together, these two new ages greatly expand the known extent of magmatism at ca 1500 Ma. The Mount Godkin Granite forms a prominent, topographically high range ca 45km northwest of Cloncurry. It intrudes the Corella Formation and has a distinct ellipsoid mapped extent. On the basis of geochemistry, Budd et al. (2001) included the Mount Godkin Granite in the Burstall Suite. The crystallisation age reported here (1739 ± 3 Ma) for sample 2804771/DPMI041 is within error of the most recent published ages from the Burstall Granite and Lunch Creek Gabbro (i.e. 1740 ± 3 Ma, 1737 ± 3 Ma, 1739 ± 3 Ma; Neumann et al., 2009) confirming broadly synchronous emplacement. We also sampled a fine-grained, leucocratic and miarolitic biotite granite from the far northern tip of the Burstall Granite (mapped as subunit l). Despite being lithologically and texturally distinct from the main body of Burstall Granite, this sample (2804773/DPMI054) yielded a similar crystallisation age (1736 ± 4 Ma) to the main Burstall Granite and Lunch Creek Gabbro bodies (Neumann et al., 2009). A lithologically similar, unfoliated, miarolitic leucogranite was sampled from Exco Resources drill core EMCDD094 (534.85–536.07 m) at Mount Colin mine near the contact between the Burstall Granite and Corella Formation. In drill core, this granite contains large xenoliths of Corella Formation and locally transitions to a crystallised hydrothermal phase. It appears intimately associated with copper mineralisation and the crystallisation age of 1737 ± 3 Ma determined here (2804792/DPMI080) may be similar to the mineralisation age. The Myubee Igneous Complex and Overlander Granite intrude the Corella Formation in the southern part of the Mary Kathleen Domain. They were thought to have been emplaced at about the same time as the nearby Revenue Granite, the Mount Erle Igneous Complex farther south, and the Burstall Granite to the north, based on lithological and chemical similarities (e.g., Bultitude et al., 1978, 1982; Blake et al., 1984). These last three units have yielded U–Pb zircon (SHRIMP) ages in the 1735–1740 Ma range (Neumann et al., 2009; Geoscience Australia, 2011; Kositcin et al., 2019). However, Bierlein et al. (2011) reported slightly younger SHRIMP zircon emplacement ages in the 1718–1722 Ma range for parts of the Revenue Granite and Mount Erle Igneous Complex, suggesting the units are composite. The 1740 ± 5 Ma age yielded by the Overlander Granite as part of the current study is similar to ages recorded for the units listed above and, therefore, supports the interpretations of earlier workers. The granite is associated spatially with several small Cu–Au deposits in nearby country rocks (Corella Formation) including the Overlander group of mines (abandoned) and prospects, and the Andy’s Hill (Cu–Au–Co–La) and Scalper (Cu–Au) prospects (Denaro et al., 2003), but a genetic relationship between the granite and mineralisation has yet to be unequivocally demonstrated. Granite of the Myubee Igneous Complex yielded a slightly younger age of 1727 ± 5 Ma. We interpret this as a minimum age for igneous crystallisation of the granite, because most of the SHRIMP zircon analyses preserve evidence of post-crystallisation isotopic disturbance. However, it does support the conclusion of Passchier (1992) who deduced that the Myubee Igneous Complex is slightly younger than the nearby Revenue Granite, based on structural criteria. According to Passchier D1 (local) structures in the Revenue Granite are not present in the Myubee Igneous Complex. The significance of the anomalously young SHRIMP, zircon age of 1722 ± 5 Ma subsequently reported by Bierlein et al. (2011) for the Revenue Granite has yet to be resolved. The dated sample of Wimberu Granite is from a relatively small lobe, separated from the main outcrop area to the east by an extensive cover of younger Georgina Basin rocks. The lobe is located ~11 km east of the Pilgrim Fault Zone, which marks the eastern boundary of the Mary Kathleen Domain. The analysed sample yielded a U–Pb zircon age of 1518 ± 5 Ma, which is similar to the U–Pb (SHRIMP) zircon ages reported previously for different parts of the main body of Wimberu Granite east of Devoncourt homestead—namely 1508 ± 4 Ma (Page & Sun, 1998) and 1512 ± 4 (Pollard & McNaughton, 1997). <b>Bibliographic Reference: </b>Bodorkos, S., Purdy, D.J., Bultitude, R.J., Lewis, C.J., Jones, S.L., Brown, D.D. and Hoy, D., 2020. Summary of Results. Joint GSQ–GA Geochronology Project: Mary Kathleen Domain and Environs, Mount Isa Inlier, 2018–2020. <i>Queensland Geological Record</i><b> 2020/04</b>.

<p>Understanding the geological evolution and resource prospectivity of a region relies heavily on the integration of different geological and geophysical datasets. Geochronology is one key dataset, as it underpins meaningful geological correlations across large regions, and also contributes to reconstruction of past tectonic settings. Using geochronology in combination with other datasets requires the geochronology data to be available in a unified dataset with a consistent format. Northern Australia is a vast and relatively underexplored area that offers enormous potential for the discovery of mineral and energy resources. The area has a long and variably complex tectonic history, which is yet to be fully understood. Numerous geochronology studies have been completed at various scales throughout northern Australia over several decades; however, these data are scattered amongst numerous sources, limiting the ease with which they can be used collectively. <p>The objective of this work is: <p>(1) to combine Uranium–Lead (U–Pb) data across north-northeastern Australia into one consistent dataset, and <p>(2) to visualise the temporal and spatial distribution of the U–Pb age data through thematic maps as a tool for better understanding the geological evolution and resource potential of northern Australia. <p>In this contribution, over 2000 U–Pb ages from the Northern Territory, Queensland, eastern Western Australia and northern South Australia have been compiled into a single, consistent dataset. Data were sourced from Geoscience Australia, State and Territory geological surveys and from academic literature. The compilation presented here includes age data from igneous, metamorphic and sedimentary rocks. Thematic maps of magmatic crystallisation ages, high-grade metamorphic ages and sedimentary maximum depositional ages have been generated using the dataset. These maps enable spatial and temporal trends in the rock record to be visualised up to semi-continental scale and form a component of the ‘Isotopic Atlas’ of northern Australia currently being compiled by Geoscience Australia.

This Record presents new U Pb geochronological data, obtained via Sensitive High Resolution Ion Micro Probe (SHRIMP), from nine samples of sedimentary rocks collected from the Paleo- to Neoproterozoic Birrindudu and Victoria Basins, and underlying basement from the Victoria River catchment region, northwest Northern Territory. The newly acquired U–Pb SHRIMP data are discussed and integrated with existing detrital zircon geochronology to assist in the determination of maximum depositional ages and sedimentary provenance during the evolution of the Birrindudu and Victoria Basins, and contribute to lithostratigraphic correlations with other Proterozoic basins across northern Australia (e.g., the greater McArthur Basin and the Centralian Superbasin, Walter et al., 1995; Munson et al., 2013; Carson, 2013; Munson, 2016).