Numerical Modeling of Reaction-Enhanced Fluid Flow and Isotopic Exchange in Contact Aureoles

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Along with metamorphism, fluid flow is the most important process that occurs in contact aureoles of igneous intrusions. Fluid flow drives metamorphic reactions and induces advective heat and mass transport. There is a very large body of field, chemical, mineralogic, and fluid inclusion data that demonstrate that magmatic-hydrothermal systems are very complex, spatially variable, and compositionally evolve through time as thermal conditions change. However, the temporal evolution of these processes during a contact metamorphic event is often difficult to decipher from petrology and geochemistry. Numerical computer techniques provide means to examine two and three-dimensional aspects of contact aureole evolution with time. The goal of this research is to numerically examine how transient permeability changes that are inherent to rocks in which metamorphic reactions produce volatiles, influence fluid fluxes, compositions of evolving fluids, and chemical exchange between rocks and fluids in magma-driven hydrothermal system. The results will serve as a guide for interpreting mineralogic, trace element and stable isotope signatures of fluid flow in fossil magmatic-hydrothermal systems. In a broader context, this study will enhance our understanding of the long-term behavior of deep, magma-driven hydrothermal systems, including volcanic and geothermal systems, and ore-generating processes. These hydrothermal systems have played a key role in mass redistribution in the Earth's crust and its chemical evolution and are responsible for concentrating metals that can be explored economically. This project will train a graduate student that will be proficient in computational modeling of complex processes. In terms of outreach to the community, an undergraduate student will be hired to help in production of a guide to the software that could be later distributed to interested parties.