R8: Metamorphic rocks and tectonics

[R8P-11] Pressure–temperature condition of pelitic gneisses from the Mutis Metamorphic Complex, Timor Island, Indonesia

*Fransiska Ayuni Catur Wahyuandari¹, Yasuhito Osanai¹, Nobuhiko Nakano¹, Tatsuro Adachi¹, Nugroho Imam Setiawan² (1. Kyushu University, 2. Universitas Gadjah Mada)

Keywords:Geothermobarometry, P-T condition, Mutis Metamorphic Complex, Timor

Garnet-bearing pelitic gneisses mostly exhibit prograde zoning pattern meanwhile 1 rock sample of pelitic gneiss containing sillimanite exhibits homogenous wide core with a retrograde thin rim. Partial replacement of garnet grain by biotite, chlorite, and other secondary minerals suggest that metamorphic rocks in Mutis metamorphic complex are affected by retrograde metamorphism during cooling.