The goal of this investigation is to increase understanding of metamorphic reactions and fluid behavior in subduction zones by constructing a 2-dimensional numerical heat transfer model that incorporates heat conduction, advection, and metamorphic reactions. The numerical model will predict the thermal evolution and fluid production within a subduction zone as a function of time and position. Parameters to be varied include the age of oceanic lithosphere, convergence rate, volatile content of oceanic crust, and the nature and enthalpy of metamorphic dehydration and hydration reactions. This model differs from previous thermal models of subduction zones in that (1) both dehydration reactions in the downgoing slab and hydration reactions in the overlying mantle wedge are incorporated and (2) the model predicts fluid production as a function of depth. The validity of the model will be tested by comparison with surface heat flow measurements from Tohoku, Japan and rocks of the Trinity thrust system, a Devonian paleo-subduction zone located in northern California. The results of this investigation will provide insight into the generation of arc magmas.
