Thermodynamic Modeling of Fluid-Rock Interaction at Mid-Crustal to Upper-Mantle Conditions

摘要

Fluid-rock interaction is important in a wide range of settings in the middle crust to the upper mantle. Fluids are liberated in the crust during prograde metamorphism in convergent-margin settings. At greater depth, devolatilization of subducting lithosphere plays a major role in global element cycling, metasomatic alteration of the mantle, and the genesis of arc magmas. Mafic magmas produced in these settings may stall in the lower crust and liberate volatiles that metasomatize surrounding rocks and trigger production of silicic magmas of crustal derivation. Mounting evidence points to an important role for metasomatic alteration by saline brines in the genesis of some lower-crastal granulite-facies metamorphic terranes.