R8: Metamorphic rocks and tectonics

[R8-02] LA-ICP-MS zircon U-Pb ages from Oshima metamorphic rocks and their tectonic background

*Yasuhito Osanai¹, Ippei Kitano¹, Nobuhiko Nakano¹, Tatsuro Adachi¹, Sinh Vuong Bui¹, Masayuki Komatsu² (1. Kyushu Univ., SCS., 2. Ehime Univ., Sci.)

Keywords:Zircon U-Pb age, 2 stage metamorphism, Oshima metamorphic rocks, tectonic background

LA-ICP-MS zircon U-Pb ages were determined using 7 metamorphic rocks and related 4 plutonic rocks from the high-grade Oshima metamorphic rocks. Age of igneous activity indicates 113-108 Ma. On the other hand, ages of 2 stage of metamorphism were also detected as 121-118 Ma and 110-108 Ma. These igneous and metamorphic evolutions would be tectonically related with Higo metamorphic rocks, Kanto Mountains, and Akukuma metamorphic belt.