Experimental constraints on the hydartion retas of peridotites in the mantle wedge condition

Abstract

In order to obtain the hydration rates of peridotites under mantle wedge conditions, we have conducted the hydration experiments using the piston–cylinder apparatus at 580°C and 1.3 GPa. The reaction was not clearly discernible in olivine powder. In contrast, olivine in lherzolite powder was reacted with SiO₂ released during orthopyroxene alteration. The obtained conversion degrees were fitted using the Avrami equation. Then, we got the apparent growth velocity G ~ 1μm/day. Comparing the G value with the porous flow velocities, it is inferred that the mostly complete hydration reaction will be established in the slow porous flow.