R8: Metamorphic rocks and tectonics

[R8-10] Metamorphism and geochronology of epidote blueschists and eclogitic rocks from the Gotsu area, SW Japan

*Akira Takasu¹, Fazle Md Kabir², Shunsuke Endo¹, Weimin Li³ (1. Shimane Univ., 2. Fujii Consulting & Associates, 3. Jiling Univ. Chaina)

Keywords:Suo belt, Renge belt , blueschist, pseudosection modeling, K-Ar age

The peak metamorphic conditions blueschist and eclogitic rock exposed in the Gotsu area are estimated as 475-500 C, 14-16 kbar and 570-580 C, 24-25 kbar, respectively. The eclogitic rock is probably correlated to the eclogites in the Renge belt because of the similarity of mode of occurrence and metamorphic condition. K-Ar age of phengite separated from the eclogitic rock is measured as 216 +- 4.6 Ma, which is not the age of the Range metamorphic rock (ca. 300 Ma) but the Suo metamorphic rock (ca. 200 Ma).