Constraints on the Proterozoic supercontinent cycle from the structural evolution of the south-central Musgrave Province, central Australia

Constrained aeromagnetic interpretation and modelling in the south-central Musgrave Province has produced a model of the regional structural evolution that permits links to be made between localised structural studies and continent-scale tectonic models. Eight deformation events were defined in this region, several of which can be interpreted in the context of tectonic events related to the formation and break-up of Proterozoic supercontinents. D1 reflects northwest-southeast shortening during the ca. 1200 Ma Musgravian Orogeny, and its structure suggests that the Musgravian Orogeny occurred due to re-organisation of the Australian and Mawson continents during Rodinia assembly, rather than as part of a supercontinent-scale orogenic belt. D3 is interpreted to represent north-south shortening ca. 1060 Ma, characterised by inversion of extensional architecture developed during the ca. 1080 Ma Giles Event. D3 occurred in an intraplate environment, probably as a result of continued Rodinia assembly. D4 is characterised by northeast-southwest extension and dyke emplacement, probably ca. 800 Ma, which is consistent with a northwest-trending aulacogen extending across South Australia during Rodinia break-up. The ca. 550 Ma Petermann Orogeny is characterised by pervasive reactivation of pre-existing architecture under north-south shortening (D5 and D6) followed by dextral transpression on east and southeast-trending crustal-scale shear zones (D7). This intraplate deformation resulted from a compressive stress field during the assembly of Gondwana, probably due to the collision of India with Australia's western margin, and the initiation of subduction at the eastern margin of the Australian continent. The structural evolution of the Musgrave Province is therefore intimately linked with the supercontinent cycle, and provides a model of the architecture, deformation pattern and stress field of central Australia throughout the Proterozoic, which is an important constraint on the possible configurations of Rodinia and Gondwana.