Monitoring dehydration reactions in natural serpentinite assemblages at subduction zone conditions with implications for fluid transfer,, vo

Deserpentinisation in subduction zones has potential implications regarding seismicity, contribution to arc volcanism or the coupling/decoupling transition between slab and mantle. Indeed, one of the particularities of serpentine destabilisation is that it can produce large quantities of aqueous fluids at depths (serpentine =13 wt.% H2O). We will monitor the evolution of one of the dehydration reaction "Fe-brucite + antigorite” that occurs in natural hydrous rock assemblages containing multiple hydrous phases during subductions by X-ray diffraction using resistively heated diamond anvil cell. Our purpose is to constrain the nucleation of solid dehydration products, the reaction progress, the kinetics and the P/T dependence of the reaction.