U – Pb zircon ages from leucogneiss in the Etheridge Group and their significance for the early history of the Georgetown region, north Queensland

Detrital zircon ages in Neoproterozoic to Ordovician siliciclastic rocks, northeastern Australia: implications for the tectonic history of the East Gondwana continental margin

“…5). Detrital zircon ages for the Neoproterozoic succession have only minor input from sources on the adjoining north Australian craton, such as the Barramundi Orogeny, which was widespread in northern Australia at 1840-1870 Ma (Betts et al 2002), and abundant Early Mesoproterozoic (1550-1600 Ma) silicic igneous activity in the Georgetown and Mt Isa Inliers (Scott et al 2000;Black et al 2005).…”

“…Uplift of these rocks is related to reactivation of the Late Mesoproterozoic orogenic belt during the Pan-African events associated with the assembly of Gondwana (Camacho et al 2002). Significant uplift of the rift shoulder during the 600 Ma rifting event that formed the East Gondwana passive margin is unlikely as the detrital zircons of 1550-1660 Ma age are scarce in the Neoproterozoic succession, yet this is the dominant age of igneous rocks in the neighbouring Georgetown Inlier (Black et al 2005).…”

Conductively driven, high‐thermal gradient metamorphism in the Anmatjira Range, Arunta region, central Australia

“…Chewings Event-aged tectonism in the Arunta region corresponds temporally to tectonism in the Georgetown-Coen-Yambo Inliers (Blewett & Black, 1998;Black et al, 2005), Mount Isa Inlier (e.g. Rubenach et al, 2008), Curnamona Province (e.g.…”

Accretion on the long-lived continental margin of northeastern Australia

“…Extensive areas of migmatite and anatectic granite also are present. The main age constraints are based on zircon dates from felsic leucogneiss, considered to represent feldspathic psammite, for which simple zircon populations suggesting a maximum depositional age of c. 1705 Ma (Black et al, 2005). Rare granite gneisses give ages of 1695-1685 Ma (Black et al, 1998;Neumann and Kositcin, 2011).…”

“…The Etheridge Group is multiply deformed with the complexity of the deformation increasing eastwards, along with metamorphic grade which increases from greenschist to local granulite facies. A province-wide deformation history is apparent from regional structural analysis and relationships (Withnall et al, 1997), zircon dating (Black et al, 1998(Black et al, , 2005, and microstructural studies combined with EPMA monazite dating (Cihan et al, 2006…”