Metamorphic evolution of the Georgetown Inlier, northeast Queensland, Australia; evidence for an accreted Palaeoproterozoic terrane?

Abstract

Mineral textures, coupled with thermodynamic modelling in the of mid-amphibolite facies metapelites from the Georgetown Inlier, northeast Australia, point to the recording of two separate and unrelated metamorphic events. The first occurred contemporaneously with Palaeo- to Mesoproterozoic orogenesis and involved heating and burial to temperatures and pressures of approximately 600-650°C and 6.0-7.0 kbar. Textural evidence for the up-temperature (and pressure) prograde part of this path is inferred from the inclusion of garnet in biotite and staurolite. The second metamorphic event resulted in a low-pressure thermal overprint that is equated with the advective addition of heat to the terrane..