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Apatite REE spidergraphs, normalized to primitive mantle values (McDonough and Sun 1995).

Analytical conditions for the Lu–Hf and Ti-in-quartz laser sessions (named after the four study areas for this paper). *Laser spot diameters for standards are given within brackets.

Concordia and weighted mean U–Pb plots for the secondary zircon, apatite, monazite and titanite standards. MSWD, mean squared weighted deviation; n, number of analyses.

Isochron and weighted mean plots for the Lu–Hf matrix-correction standard (OD-306) and secondary standards HR-1 and Bamble-1. MSWD, mean squared weighted deviation; n, number of analyses; P(χ2), Chi-squared probability for a single data population. Where required (i.e. insufficient spread along the isochron), the isochrons were anchored to an initial 177Hf/176Hf ratio of 3.55 ± 0.05 (see text).

Full Concordia plots for the zircon U–Pb data from the Reynolds–Anmatjira samples. The age calculation is based on the youngest concordant grains (green symbols) only. MSWD, mean squared weighted deviation; P(χ2), Chi-squared probability for a single data population.

Supporting descriptive text, summary data and plots for the apatite fission track analysis, apatite U-Pb dating, and the thermal history modelling

The Beetaloo Sub-basin, northern Australia, is considered the main depocentre of the 1000 km-scale Mesoproterozoic Wilton package of the greater McArthur Basin—the host to one of the world’s oldest hydrocarbon resources. The ca. 1.40–1.31 Ga upper Roper Group and the latest Mesoproterozoic to early Neoproterozoic unnamed group of the Beetaloo Sub-basin, together, record ca. 500-million-years of depositional history within the North Australia Craton.Whole-rock shale Sm–Nd and Pb isotope data from these sedimentary rocks reveal their provenance and evolution from ca. 1.35 to 0.85 Ga. Further, these data, together with shale major/trace element data from this study and pyrolysis data from previous publications, are used to develop a dynamic tectonic geography model that links the organic carbon production and burial to an enhanced nutrient supply by weathering of a large igneous province. The ca. 1.35–1.31 Ga Kyalla Formation of the upper Roper Group is composed of isotopically evolved sedimentary detritus that passes up, into more isotopically juvenile Pb values towards the top of the formation. The increase in juvenile compositions coincides with elevated total organic carbon (TOC) contents of these rocks. The coherently enriched juvenile compositions and TOC in the upper portions of the Kyalla Formation are interpreted to reflect an increase in nutrient supply (e.g. phosphorous) associated with the weathering of basaltic sources. Possible, relatively juvenile, basaltic sources include the Wankanki Supersuite in the western Musgraves and the Derim Derim–Galiwinku large igneous province (LIP). The transition into juvenile, basaltic sources directly before a supersequence-bounding unconformity, is here interpreted to reflect uplift and erosion of the Derim Derim–Galiwinku LIP, rather than an influx of southern, Musgrave sources. A new baddeleyite crystallisation age of 1312.9 ± 0.7 Ma provides both a tight constraint on the age of this LIP, along with its associated magmatic uplift, as well as providing a minimum age constraint for deposition of the Roper Group. The unconformably overlying lower and upper Jamison sandstones are at least 300 million years younger than the Kyalla Formation and were sourced from the Musgrave Province. An up-section increase in isotopically juvenile compositions seen in these rocks are interpreted to document the progressive exhumation of the western Musgrave Province. The overlying Hayfield mudstone received detritus from both the Musgrave and Arunta regions, and its isotopic geochemistry reveals affinities with other early Neoproterozoic basins (e.g. Amadeus, Victoria and Officer basins), indicating the potential for inter-basin correlations.

Four separate sub-themes presented for the AGES 2020 meeting in Alice Springs that was cancelled due to the Coronavirus pandemic. Themes are:1. Combined apatite U-Pb and whole-rock Rb-Sr geochronology of the Derim Derim dolerite2. Reconstructing the Mesoproterozoic palaeogeography of northern Australia through detrital thermo- and geo-chronometers.3. Late Palaeoproterozoic to early Mesoproterozoic redox conditions--proxies from the Tawallah and Lower McArthur Groups4. Age constraints and provenance of the Tomkinson Province--the southernmost greater McArthur BasinThe poster presents the work of the ARC McArthur Basin Linkage team, supported by the Northern Territory Geological Survey, Santos Ltd., Origin and Imperial Oil and Gas and involving The University of Adelaide, UniSA, The University of Wollongong and the Czech Academy of Sciences. The poster is largely the work of Angus Nixon, Morgan Blades, Bo Yang and Darwinaji Subarkah.

Appendix 3: Radial plots

Figure S1. Zircon CL

Appendix 5: Time–temperature models for KM-07, KM-14A and KM-15

Appendix 4: Detailed modelling parameters and necessary information for this study

Garnet is a fundamental expression of metamorphism and one of the most important minerals used to constrain the thermal conditions of the crust. We used innovative in situ laser-ablation ICP-MS/MS Lu-Hf geochronology to demonstrate that garnet in metapelitic rocks enclosing Cambrian eclogite in southern Australia formed during Laurentian Mesoproterozoic metamorphism. Garnet porphyroblasts in amphibolite-facies metapelitic rocks yielded Lu-Hf ages between 1286 ± 58 Ma and 1241 ± 16 Ma, revealing a record of older metamorphism that was partially obscured by metamorphic overprinting during ca. 510 Ma Cambrian subduction along the East Gondwana margin. Existing detrital zircon age data indicate the protoliths to the southern Australian metapelitic rocks were sourced from western Laurentia. We propose that the metapelitic rocks of southern Australia represent a fragment of western Laurentian crust, which was separated from Laurentia in the Neoproterozoic and incorporated into the East Gondwana subduction system during the Cambrian. The ability to obtain Lu-Hf isotopic data from garnet at acquisition rates comparable to those for U-Pb analysis of detrital zircon means, for the first time, the metamorphic parentage of rocks as expressed by garnet can be efficiently accessed to assist paleogeographic reconstructions.

The Southern Irumide Belt (SIB) is an orogenic belt consisting of a number of lithologically varied Mesoproterozoic and Neoproterozoic terranes that were thrust upon each other. The belt lies along the southwest margin of the Archaean to Proterozoic Congo Craton, and bears a Neoproterozoic tectono-thermal overprint relating to the Neoproterozoic–Cambrian collision between the Congo and Kalahari cratons. It preserves a record of about 500 million years of plate interaction along this part of the Congo margin. Detrital zircon samples from the SIB were analysed for U–Pb and Lu–Hf isotopes, as well as trace element compositions. These data are used to constrain sediment-source relationships between SIB terranes and other Gondwanan terranes such as the local Congo Craton and Irumide belt and wider afield to Madagascar (Azania) and India. These correlations are then used to interpret the Mesoproterozoic to Neoproterozoic affinity of the rocks and evolution of the region. Detrital zircon samples from the Chewore–Rufunsa and Kacholola (previously referred to as Luangwa–Nyimba) terranes of the SIB yield zircon U–Pb age populations and evolved εHf(t) values that are similar to the Muva Supergroup found throughout eastern Zambia, primarily correlating with Ubendian–Usagaran (ca. 2.05–1.80 Ga) phase magmatism and a cryptic basement terrane that has been suggested to underlie the Bangweulu Block and Irumide Belt. These data suggest that the SIB was depositionally connected to the Congo Craton throughout the Mesoproterozoic. The more eastern Nyimba–Sinda terrane of the SIB (previously referred to as Petauke–Sinda terrane) records detrital zircon ages and εHf(t) values that correlate with ca. 1.1–1.0 Ga magmatism exposed elsewhere in the SIB and Irumide Belt. We ascribe this difference in age populations to the polyphase development of the province, where the sedimentary and volcanic rocks of the Nyimba–Sinda terrane accumulated in extensional basins that developed in the Neoproterozoic. Such deposition would have occurred following late-Mesoproterozoic magmatism that is widespread throughout both the Irumide and Southern Irumide Belts, presently considered to have occurred in response to collision between a possible microcontinental mass and the Irumide Belt. This interpretation implies a multi-staged evolution of the ocean south of the Congo Craton during the mid-Mesoproterozoic to late-Neoproterozoic, which ultimately closed during collision between the Congo and Kalahari cratons. Keywords: Detrital zircon geochronology, Tectonics, Hafnium isotopes, Zambia, Southern irumide belt, Irumide belt