The Rice Hydrothermal system is an ideal location to evaluate the relative contributions of magmatic and 18O- shifted meteoric reservoirs to a hydrothermal fluid. Three plume fluid models (no mixing, progressive upward dilution, and a spike of magmatic fluid) will be tested by measuring fluid parameters ( D, 18O, temperature, and salinity) which vary with the degree of mixing between two "end-member" fluids. The plume hypothesis itself will be tested by studying the effects of water/rock interaction in sedimentary rocks in the Rico dome.
