Reaction kinetics of Si-metasomatism and serpentinization on olivine-quartz-H₂O system

Abstract

Hydrothermal experiments (230̊C, P_sat) were carried out in olivine (Ol)–quartz (Qtz)–H₂O system, as analogues of crust-mantle boundary. The mineralogy of the reaction products in the Ol-hosted region changed with increasing distance from the Ol–Qtz boundary, from talc to serpentine + magnetite. On the other hand, in Qtz-hosted region, talc was also formed. Talc zone was formed 1.0 mm from the boundary in Ol-hosted region, whereas it also formed 0.5 mm from the boundary in Qtz-hosted region.