Australian Proterozoic orogenic belts are typically characterised by high-temperature, low-pressure, long-lived metamorphism and near-isobaric cooling. However, this is not the case for the Nimbuwah Domain, the easternmost part of the Pine Creek Orogen and part of the oldest core of the North Australian Craton. Here we present new field relationships, geochemical, metamorphic, SHRIMP zircon and monazite U-Pb age, and zircon Lu-Hf and whole-rock Sm-Nd isotopic data for the Nimbuwah Complex and metasedimentary rocks of the Cahill Formation that they intruded in the Nimbuwah Domain. On the basis of these data we propose a new tectonic model for the Paleoproterozoic evolution of the Pine Creek Orogen. SHRIMP zircon U-Pb age data show that granitic to dioritic plutons of the Nimbuwah Complex were emplaced from 1871-1857 Ma at - 9.2 kbar and 650-C into thickened crust during D2-D3 west-directed thrusting and folding. This is termed the Nimbuwah Event. The Nimbuwah Complex was formed by partial melting of Neoarchean granites in the mid to lower crust and mixing with a juvenile magma component. The overthickened crust underwent extensional uplift to <5 kbar by 1855 Ma, constrained by monazite growth during garnet breakdown associated with syn- to late-D2 decompression. We propose that crustal thickening and magmatism occurred in response to collision of Neoarchean to Paleoproterozoic basement of the Pine Creek Orogen (the over-riding plate) with an unknown collider, now concealed beneath younger cover to the east. Exhumation of at least a 15 km crustal thickness within only a few million years indicates a short period of collisional orogenesis, consistent with the observed metamorphic evidence for a low thermal gradient during crustal thickening. Tectonic uplift and erosion of the Nimbuwah Complex fed the retro-arc Cosmo Supergroup and possibly other Paleoproterozoic successions of the North Australian Craton that are dominated by c. 1870 Ma detritus. The low thermal gradient in overthickened crust, which is unusual for Proterozoic Australia, might be a consequence of collision between relatively cool, rigid Archean blocks.

This Record presents new Sensitive High Resolution Ion Micro Probe (SHRIMP) U–Pb geochronological results from the Aileron Province that were obtained during the Northern Territory Geological Survey–Geoscience Australia (NTGS–GA) geochronology project under the National Collaboration Framework (NCF) agreement, in July 2020. Geoscience Australia’s contribution to this project forms part of the Exploring for the Future (EFTF) Program, which aims to better understand the mineral, energy, and groundwater resources of Northern Australia. <b>Bibliographic Reference:</b> Kositcin N, Beyer EE and Reno BL, 2021. Summary of results. Joint NTGS–GA geochronology project: Aileron Province, Jinka and Dneiper 1:100 000 mapsheets, 2020. <i>Northern Territory Geological Survey, Record</i><b> 2021-008</b>.

This Record presents data collected in September 2019 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 (EFTF) Program. Two new U–Pb SHRIMP zircon geochronological results derived from two samples of the Balbirini Dolostone (southern McArthur Basin, Northern Territory) are presented herein. The Balbirini Dolostone is part of the early Mesoproterozoic Nathan Group, and is a thick unit of interbedded dolostone and dolomitic siliciclastic rocks that include evaporitic redbeds. The two samples were collected in June 2019 from the type section of the Balbirini Dolostone in southern BAUHINIA DOWNS (MALLAPUNYAH). <b>Bibliographic Reference:</b> Kositcin N, and Munson TJ, 2020. Summary of results. Joint NTGS–GA geochronology project: Balbirini Dolostone, southern McArthur Basin, June 2019–September 2019. <i>Northern Territory Geological Survey</i>, <b>Record 2020-002</b>.

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/)

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 Record presents twelve new zircon U-Pb geochronological results from the South Nicholson region, conducted on Geoscience Australia’s Sensitive High Resolution Ion Micro Probe (SHRIMP), as part of the Commonwealth Government’s Exploring for the Future (EFTF) program, an initiative to better understand the mineral, energy and groundwater potential of northern Australia. These data will facilitate greater understanding of the geological evolution of the South Nicholson region, a vast and underexplored region extending across north-eastern Northern Territory and far north-western Queensland. Samples were collected from across the South Nicholson region including MOUNT DRUMMOND, CALVERT HILLS, BRUNETTE DOWNS (NT), LAWN HILL and CAMOOWEAL (QLD) 250K mapsheets. Four samples are from outcrop and eight samples from six stratigraphic and exploration drillholes. Samples were collected from the Paleoproterozoic Murphy Province and from overlying successions of the Paleoproterozoic Benmara Group and the Mesoproterozoic South Nicholson Group. Several samples from drillholes, have stratigraphic affinities that are uncertain and speculative.

This Record presents new Sensitive High Resolution Ion MicroProbe (SHRIMP) U-Pb zircon results from the Mount Isa Orogen obtained under the auspices of the Geological Survey of Queensland-Geoscience Australia (GSQ-GA) National Collaboration Framework (NCF) geochronology project between July 2016 and June 2017. New results are presented from eight samples collected as part of ongoing regional mapping and geoscientific programs in the Mount Isa Orogen. GA work presented here represents part of the federally funded Exploring for the Future Program. As a part of ongoing geological mapping in the Mount Isa Orogen, the Geological Survey of Queensland (GSQ) and Geoscience Australia (GA) have undertaken a geochronology program to enhance the understanding of the geological evolution of the province. There are two focus areas as a part of this Record. The first focus area is north of Mount Isa, in the Kalkadoon-Leichhardt and Sybella domains (Figure i), and includes geochronology results from three mafic to intermediate rocks. The second focus area is south of Cloncurry, in the Kuridala–Selwyn and Marimo–Staveley domains (Figure i), and includes geochronology results from one leucogranite and four sedimentary rocks. For ease of reporting, these two focus areas are split into two themes 1) ‘mafic rocks’ for the three geochronology results north of Mount Isa; and 2) ‘Kuridala–Selwyn corridor’ for the five geochronology results south of Cloncurry. <b>Bibliographic Reference:</b> LEWIS, C.J., WITHNALL, I.W., HUTTON, L.J., BULTITUDE, R.J., SLADE, A.P., SARGENT, S., 2020. Summary of results. Joint GSQ–GA geochronology project: Mount Isa region, 2016–2017. <i>Queensland Geological Record</i><b> 2020/01</b>.

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.

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.

This Record presents new Sensitive High Resolution Ion Microprobe (SHRIMP) U–Pb geochronological results for samples collected from the Mount Isa Inlier and covered areas to the east. The Mary Kathleen Domain is the focus of this work and 11 metasedimentary and igneous samples were analysed from across the distribution of the domain. An additional two metasedimentary samples and one igneous sample from drill cores located east of the outcropping Mount Isa Province were also analysed. <b>Bibliographic Reference: </b>Kositcin, N., Purdy, D.J., Bultitude, R.J., Brown, D.D. & Hoy, D. Summary of Results. Joint GSQ–GA Geochronology Project: Mary Kathleen Domain and rocks under younger cover east of the Mount Isa Inlier, 2019–2020. <i>Queensland Geological Record</i><b> 2021/01</b>.