S2: Water Rock Interaction (Special Session)

[S2P-01] Fluid mediated dissolution and reprecipitation process recorded in the garnet of the HP marble collected from the Sanbagawa eclogite mass.

*Kenta Yoshida¹, Hikaru Sawada¹, Sota Niki², Ryosuke Oyanagi³ (1. JAMSTEC, 2. Uni. Tokyo, 3. Kokushikan Uni.)

Keywords:pre-Sanbagawa metamorphism, dissolution and reprecipitation process, fluid infiltration, micro pore

We have performed FIB-SEM 3D analysis of the microtexture of the garnet underwent fluid-mediated dissolution and reprecipitation process during the exhumation of the eclogite unit. We found nano- to micro-pores along the boundary. Recent studies revealed that such pores in the reaction front would strongly enhance the fluid-mediated dissolution and reprecipitation process. This study indicated that a similar mechanism played a role in the garnet-replacement reaction in the studied sample.