The kinetics and mechanisms of plagioclase behavior during certain igneous, metamorphic, and deformational processes will be experimentally investigated. NaSi-CaAl interdiffusion rates will be studied. The hydrogen-bearing species in feldspar will be studied using an ion microprobe, and the concentrations of these species correlated with pressure and temperature. Nucleation of jadeite and quartz during the breakdown of albite will be studied using natural starting materials with different amounts of overstepping of the equilibrium boundary and TEM used to evaluate various factors in determining the nature and rate of nucleation. These results will provide major advances in our ability to interpret the behavior of feldspar in the earth's crust (It is one of the most common minerals.), as well as fundamental information about the factors which affect the kinetics and mechanisms of mineralogical processes in general.
