(Th U)-Pb monazite ages from Al-Mg-rich metapelites, Rauer Group, east Antarctica

Abstract

The age of high-temperature granulite-facies metamorphism (> ∼800-850 °C) in the Rauer Group, Prydz Bay, east Antarctica, is relevant for establishing the metamorphic and temporal architecture of the Prydz Bay mobile belt. Monazites within Al-Mg-rich granulite-facies metapelites give an overall tanh-estimated Pan-African age of ∼511 ± 4 Ma (2σ) using in-situ electron microprobe-based (Th + U -Pb chronology, consistent with existing U-Pb zircon geochronology from the Rauer Group and Prydz Bay. Monazite occurs primarily within cordierite-bearing coronae and symplectic mineral reaction textures, and also within biotite. Pan-African granulite-facies metamorphism is preferred as responsible for t..