Spatio–temporal evolution of Mesoproterozoic magmatism in NE Australia: A hybrid tectonic model for final Nuna assembly

Volante, Silvia; Collins, William J.; Barrote, Vitor; Nordsvan, Adam R.; Pourteau, Amaury; Li, Z.-X.; Li, J.; Beams, S. D.

doi:10.1016/j.precamres.2022.106602

Cited by 12 publications

(3 citation statements)

References 86 publications

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“…Palaeogeographic reconstructions correlate the LGC to the Archean and Palaeoproterozoic evolution of the North Atlantic and Rae cratons prior to and during the amalgamation of the Earth's first supercontinent Nuna (Baba, 2002; Hughes et al, 2014; Park, 2022; Park & Tarney, 1987). Between 2000 Ma and 1600 Ma, major collisional orogenic belts formed across the globe as a result of convergence, accretion and collision between different major cratons and smaller crustal blocks to form the supercontinent Nuna (Figure 14; e.g., Kirscher et al, 2021; Nordsvan et al, 2022; Pourteau et al, 2018; Volante, Collins, et al, 2020; Volante, Pourteau, et al, 2020; Volante et al, 2022; Wan et al, 2020). Several active margins and convergence directions between adjacent cratonic blocks forming Laurentia and Baltica generated major Palaeoproterozoic (1900–1700 Ma) orogenic belts (Figure 14) such as the Nagssugtoqidian Orogen, following collision between the Rae and the North Atlantic cratons, and the Lapland‐Kola Orogen after the collision between the Karelia and the Kola cratons (Buchan et al, 2000; St‐Onge et al, 2009).…”

Section: Discussionmentioning

confidence: 99%

Constraints on the Palaeoproterozoic tectono‐metamorphic evolution of the Lewisian Gneiss Complex, NW Scotland: Implications for Nuna assembly

Volante,

Dziggel,

Walters

et al. 2023

Journal Metamorphic Geology

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Despite extensive investigation, the tectono‐thermal evolution of the Archean crust in the Lewisian Gneiss Complex in NW Scotland (LGC) is debated. Most U–Pb zircon geochronological and metamorphic studies have focused on rocks from the central region of the mainland LGC, where granulite facies assemblages associated with the oldest (Badcallian) tectono‐metamorphic event at c. 2.75 Ga are overprinted by younger amphibolite facies assemblages related to the Inverian (c. 2.5 Ga) and subsequent Laxfordian (c. 1.9–1.65 Ga) tectono‐thermal events. In the southern and northern regions of the mainland LGC, deformation and metamorphism associated with the Laxfordian event are pervasive, although the timing and conditions are poorly constrained. Here, we present new field, petrographic and structural data, U–Pb zircon and titanite geochronology and phase equilibrium modelling of amphibolite samples from the northern and southern regions. Our field observations show that in both regions, pre‐Laxfordian structures are significantly reworked by steep NW‐striking fabrics that are themselves pervasively overprinted by co‐axial deformation and amphibolite facies metamorphism related to the Laxfordian event. In situ U–Pb titanite geochronology yields Laxfordian ages of 1853 ± 20 Ma in the southern region (P = 6–8 kbar and T = 640–690°C) and 1750 ± 20 Ma and 1776 ± 10 Ma in the northern region (P = 6–7.5 kbar and T = 740–760°C). While U–Pb dating of zircon rims from felsic gneisses in the central region shows a dominant Inverian metamorphic overprint at c. 2500 Ma, zircon rims in felsic gneisses from the northern and southern regions commonly yield Laxfordian dates as young as c. 1800 Ma. Combined, the results support the idea that, during the Palaeoproterozoic, the central region of the LGC acted as low‐strain domain, in which intense deformation and metamorphism were restricted to crustal‐scale shear zones. By contrast, in the southern and northern regions, early (c. 1.85 Ga) and late (c. 1.75 Ga) Laxfordian deformation and fluid‐mediated metamorphism were much more pervasive and at higher P–T conditions than previously proposed. The diachronous Laxfordian evolution of the southern and northern regions indicate that they reflect early and late snapshots of collisional to transpressional tectonics in the mainland LGC. The long‐lasting Laxfordian evolution documents the collision of the Rae and North Atlantic cratons during the Palaeoproterozoic amalgamation of the supercontinent Nuna, with implications for the palaeogeographic configuration of NW Scotland during Palaeoproterozoic Nuna.

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Section: Discussionmentioning

confidence: 99%

Constraints on the Palaeoproterozoic tectono‐metamorphic evolution of the Lewisian Gneiss Complex, NW Scotland: Implications for Nuna assembly

Volante,

Dziggel,

Walters

et al. 2023

Journal Metamorphic Geology

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“…1.65–1.6 Ga 21 , 22 , 53 . Several locations have been proposed for the final suture between Australia and Laurentia, remaining this a matter of current debate 20 , 52 , 56 . Nonetheless, at 1.6 Ga E–W-directed collision between the Laurentian and Australian blocks formed a N–S-striking compressional fabric recording Barrovian-type metamorphism reflecting burial and thickening of the orogenic system 21 .…”

Section: Tectono-metamorphic Evolution During Nuna–columbiamentioning

confidence: 99%

“…Nonetheless, at 1.6 Ga E–W-directed collision between the Laurentian and Australian blocks formed a N–S-striking compressional fabric recording Barrovian-type metamorphism reflecting burial and thickening of the orogenic system 21 . This stage was followed by an extensional post-collisional stage recording low-pressure, high-temperature metamorphism and related to syn-kinematic magmatism 56 – 58 . Hence, intermediate- to high- T/P metamorphism characterized Australian Mesoproterozoic orogenic belts formed during the 1.6 Ga final Columbia assembly and no HP metamorphic rocks nor ophiolitic remnants were reported.…”

Section: Tectono-metamorphic Evolution During Nuna–columbiamentioning

confidence: 99%

Metamorphic turnover at 2 Ga related to two-stage assembly of Columbia

Volante,

Kirscher

2024

Sci Rep

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Understanding the stabilization of cratons and how this is related to the onset of plate-tectonics is among the most important questions in geoscience. The assembly of Earth’s first supercontinent Columbia represents the first lines of evidence for a global subduction network, when the oldest, deep subduction-related rocks have been reported. We combine the low-, intermediate- and high-T/P global metamorphic record with the two-stage assembly of the Nuna-Columbia supercontinent to address the significance of the oldest “cold” rocks (low-T/P) and the related emergence of bimodal metamorphic belts. For this purpose, we analyse two examples from Laurentia (including Greenland) and Australia between 2.0–1.8 Ga and 1.8–1.6 Ga. Two main observations are: (i) a first-stage (2.0–1.8 Ga) amalgamation of the megacontinent Nuna (precursor to Columbia) is characterized by bimodal metamorphism along major mobile belts suturing the megacontinent’s center. In contrast, a second-stage (1.8–1.6 Ga) is dominated by the formation of soft collisional orogens during the final Columbia supercontinent assembly, recording intermediate- to high-T/P metamorphism; (ii) the metamorphic signature of the two assembly stages, featuring low- and intermediate-T/P rocks during Nuna assembly followed by their near absence during Columbia amalgamation, contrasts with the thermobaric ratios recorded by the Phanerozoic Gondwana-Pangea assembly, where intermediate and low-T/P rocks dominated the final stage of Pangea amalgamation. This discrepancy may signify substantial changes in intraplate metamorphism and minor rearrangements during Columbia assembly compared to major continent–continent collisions, such as the Appalachian-Variscan Orogen as well as production and fast exhumation of high- to ultra-high-pressure rocks during the assembly of the supercontinent Pangea. Furthermore, the variation of thermobaric ratios aligns with the concept of a two-stage mega-supercontinent formation, emphasizing differences between the potentially oldest and youngest supercontinent cycles.

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The Columbia supercontinent: Retrospective, status, and a statistical assessment of paleomagnetic poles used in reconstructions

Meert

Santosh

2022

Gondwana Research

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Spatio–temporal evolution of Mesoproterozoic magmatism in NE Australia: A hybrid tectonic model for final Nuna assembly

Cited by 12 publications

References 86 publications

Constraints on the Palaeoproterozoic tectono‐metamorphic evolution of the Lewisian Gneiss Complex, NW Scotland: Implications for Nuna assembly

Constraints on the Palaeoproterozoic tectono‐metamorphic evolution of the Lewisian Gneiss Complex, NW Scotland: Implications for Nuna assembly

Metamorphic turnover at 2 Ga related to two-stage assembly of Columbia

The Columbia supercontinent: Retrospective, status, and a statistical assessment of paleomagnetic poles used in reconstructions

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