Reconnaissance dating of events recorded in the southern part of the Capricorn Orogen

Abstract

Zircon geochronology confirms the Errabiddy Shear Zone as a major structural boundary separating two distinct geological terranes within the southern part of the Palaeoproterozoic Capricorn Orogen of Western Australia. Rocks on the south side of the Errabiddy Shear Zone represent parts of the Archaean Yilgarn Craton that were variably reworked during the c. 2.0Ga Glenburgh and c. 1.8Ga Capricorn orogenies. Rocks on the north side represent an exotic terrane (the 'Glenburgh Terrane') comprising c. 2500Ma (and possibly older) gneisses which evidently record tectonothermal activity c. 2390Ma, and which, together with quartzitic metasedimentary units deposited after c. 2270Ma, collided with the Yilgarn Craton during the Glenburgh orogeny. Regional deformation, high-grade metamorphism and voluminous felsic plutonism occurred throughout the complex in association with both the Glenburgh and Capricorn orogenies.