Grenvillian-aged reworking of late Paleoproterozoic crust of the southern North Australian Craton, central Australia: Implications for the assembly of Mesoproterozoic Australia

摘要: Abstract LA–ICP–MS U–Pb monazite and zircon geochronology from metapelites migmatitic orthogneiss along the central southern margin of North Australia Craton (NAC), Australia, reveal presence a regional-scale Grenvillian-aged (ca. 1130 Ma) deformation system. extends over strike length 110 km Aileron Province in vicinity Alice Springs to Teapot Granite Complex within Warumpi Province. There is also evidence for migmatisation resetting further west Mount Liebig area, which may extend footprint strike-length at least 250 km. Deformation associated with reworking produced map-scale east–west trending folds strongly foliated, steeply dipping shear zones that define structural architecture interface region between Provinces. Shallow, westerly-plunging partial melting have evolved into mylonites record south-side up movement. Phase equilibria modelling age-constrained garnet–biotite ± sillimanite ± cordierite-bearing Provinces suggest metamorphism reached temperatures range 775–820 °C pressures 5–5.5 kbar, corresponding thermal gradients ∼130–165 °C kbar −1 . The extensive system reworks overprints late Paleoproterozoic 1650–1630 Ma) high-grade metamorphic rocks. occurs above south lithospheric-scale has been geophysically imaged depths 200 km. This feature was interpreted represent fossil subduction zone age. However, crust this suggests it instead be Grenvillian-aged. If case, NAC suturing Musgrave south. would effectively place long-lived, Late Mesoproterozoic ultrahot orogen an upper plate tectonic setting, linked convergence South Australian Craton.