S2: Water Rock Interaction (Special Session)

[S2-01] Metasomatic history of titanian garnet-bearing rodingite from the Nukabira ultramfic body, Kamuikotan Belt (Hokkaido, Japan)

*Yuto Kimura¹, Sota Niki², Yuki Hagiwara³, Toru Takeshita³, Tatsuki Tsujimori¹, Takahumi Hirata² (1. Tohoku Uni. Sci, 2. Univ. of Tokyo, 3. Hokkaido Univ.)

Keywords:rodingite, titanian garnet, metasomatism, serpentinite, Kamuikotan Belt

Titanian garnet-bearing rodingite suggesting which drove the mobility of Al, Ca, and Ti in the fluid. Rodingite consists of diopsides, chlorites, minor Ti-Grt, and titanites. Ti-Grt observed in two occurrence which euhedral to subhedral crystals in fine veinlets and Ti-Grt coexists with titanite and chlorite. CH₄ and H₂ detected in Raman spectroscopy and solid gas chromatography. Native copper and copper sulfate coexisting in rodingite which suggesting ~ 40 < O₂< -30 ~ of oxygen fugacity in T=400 ℃. The age of Ti-Grt in the vein derived 50.6 ± 4 Ma (MSWD = 1.7).