[S-MP25] Supercontinents and Crustal Evolution

[SMP25-08] Petrochronological evolution of UHT granulite facies metapelites from the Lundazi terrane, Irumide Belt, Eastern Zambia

*Kabangu Grace Sakuwaha¹、Toshiaki Tsunogae¹ (1.Graduate School of Life and Environmental Sciences, University of Tsukuba)

キーワード：Pelitic granulites, Metamorphic P-T, Monazite

The Lundazi Terrane is part of the Mesoproterozoic Irumide Belt of central Africa which together with other terranes of similar ages are interpreted to record magmatic and collisional events related to the assembly of the Rodinia Supercontinent. The Irumide Belt is situated in eastern Zambia and extends into neighboring Malawi, northern Mozambique, and southern Tanzania. The Lundazi Terrane consists of a felsic gneiss basement overlain by granulite facies meta-pelites. The rocks are characterized by heterogenous leucocratic and melanocratic layers which record evidence of ultra–high temperature metamorphism and peak assemblages of garnet, sillimanite, spinel, quartz, feldspars, cordierite, orthopyroxene, rare corundum, and accessory monazite and zircon. Application of geothermobarometry and phase equilibria modelling indicate peak metamorphic conditions of 900 to 1025 °C and 7-10 kbar, prior to exhumation and subsequent cooling along clockwise P-T-t paths. Monazite dating indicates the metamorphism occurred between ca.1.2 and 1.0 Ga.