R8: Metamorphic rocks and tectonics

[R8P-03] Ultrahigh-temperature metamorphism and melt inclusions from the Sør Rondane Mountains, East Antarctica

*Fumiko Higashino¹, Tetsuo Kawakami¹ (1. Kyoto Univ. Sci.)

Keywords:UHT metamorphism, nanogranitoid, mesoperthite, ternary feldspar

In the Sør Rondane Mountains (SRM), East Antarctica, ultrahigh-temperature (UHT) metamorphisms are reported from only boulders so far. A pelitic gneiss collected from an outcrop in Balchenfjella, eastern SRM, contains mesoperthite that gave UHT condition (> 900 ºC) by ternary feldspar thermometry. The UHT mesoperthite is present both in the matrix and as an inclusion in garnet. The garnet also has nanogranitoid inclusions next to the mesoperthite, which are interpreted to be an UHT melt.