The proposed research will involve theoretical studies of a variety of different kinds of reaction between fluid and rock. It will include: 1. Gravitational instabilities ranging from situations of rapid melt segregation to cases in which segregation is slow or negligible 2. Chemical exchange balanced by diffusion in the fluid phase: An application of this regime is the exchange of Sr between carbonates and their contained porewaters. 3 Exchange limited by diffusion in the solid phase. The thermal history in the vicinity of the conduit at Inyo Domes is sufficiently well known that it should be possible to determine the diffusion parameters of feldspars in their natural setting, and compare it to laboratory diffusion data to test the key assumption of thermochronometry that laboratory data can indeed be extrapolated to give geologically relevant diffusion rates.
