High-T granulites and polymetamorphism in the southern Arunta Region, central Australia: Evidence for a 1.64 Ga accretional event
MetadataShow full item record
Mapping and sensitive high-resolution ion microprobe (SHRIMP) U-Pb zircon geochronology in the newly defined Warumpi Province of the southern Arunta Region, central Australia has identified a succession of granulite facies metasedimentary rocks (the Yaya Metamorphic Complex) that has undergone a polymetamorphic Proterozoic evolution. Pelitic metasedimentary rocks of the Yaya Metamorphic Complex have a maximum deposition age of 1661+/-10 Ma, and underwent granulite facies metamorphism synchronous with intrusion of granite, charnockite and gabbro. In quartz-poor cordierite-rich rock types, peak metamorphic P-T conditions of >800 deg. C and 9-10 kbar were followed by near-isothermal decompression, with the breakdown of orthopyroxene, sillimanite and garnet to sapphirine and cordierite. Metamorphic zircon rims from a cordierite-rich granulite have an age of 1638+/-8 Ma, and two migmatitic metapelite units have similar metamorphic ages of 1641+/-14 and 1639+/-20 Ma. Amphibolite facies felsic migmatite of the Madderns Yard Metamorphic Complex has a protolith age of 1688+/-16 Ma, with evidence for metamorphism at 1640 Ma. Further localised migmatisation at amphibolite facies conditions took place at 1571+/-5 and 1149+/-3 Ma. Our evidence suggests that a major orogenic event, named here the Liebig Orogeny, affected the southern Arunta Region at 1640-1635 Ma. Zircon evidence suggests that there was less than 20 million years between the timing of deposition and deep crustal metamorphism of the Yaya Metamorphic Complex, and high-T decompression textures suggest rapid exhumation, consistent with a crustal thickening event. The distal effects of the Liebig Orogeny in the North Australian Craton include intraplate tectonism, volcanism and a hairpin bend in the apparent polar wander path, suggesting that it is an event of regional significance. We propose that the Liebig Orogeny reflects the accretion of the Warumpi Province onto the North Australian Craton at 1640 Ma.
Copyright 2005 Elsevier B.V. All rights reserved
Showing items related by title, author, creator and subject.
Polymetamorphism in the mainland Lewisian complex, NW Scotland – phase equilibria and geochronological constraints from the Cnoc an t’Sidhean suiteZirkler, A.; Johnson, Tim; White, R.; Zack, T. (2012)The metamorphic evolution of rocks cropping out near Stoer, within the Assynt terrane of the central region of the mainland Lewisian complex of NW Scotland, is investigated using phase equilibria modelling in the NCKFMASHTO ...
Tectono-thermal evolution of the Palaeoproterozoic Granites–Tanami Orogen, North Australian Craton: Implications from hornblende and biotite 40Ar/39Ar geochronologyLi, B.; Bagas, L.; Jourdan, Fred (2014)The Palaeoproterozoic Granites–Tanami Orogen (GTO) hosts a number of gold deposits located in the southern margin of the North Australian Craton. The major stratigraphic succession is the Palaeoproterozoic Tanami Group ...
Geochronological constraints on the Late Proterozoic to Cambrian crustal evolution of eastern Dronning Maud Land, East Antarctica: a synthesis of SHRIMP U–Pb age and Nd model age dataShiraishi, K.; Dunkley, Daniel; Hokada, T.; Fanning, M.; Kagami, H.; Hamamoto, T. (2008)In eastern Dronning Maud Land (DML), East Antarctica, there are several discrete, isolated magmatic and high-grade metamorphic regions. These are, from west (c. 20degE) to east (c. 50degE), the Sør Rondane Mountains (SRM), ...