Turner (1948) attempted to summarize the mineral paragenesis of metamorphic rocks in terms of Eskola’s facies concept. Since that date a considerable mass of experimental data bearing on metamorphic reactions and stability ranges of some of the simpler metamorphic minerals has appeared in various journals. Theoretical treatment of metamorphic problems from the thermodynamic standpoint, initiated by Johnston and Niggli in their classic paper (1913), has progressed notably. It is no longer satisfactory to interpret metamorphic mineral assemblages as products of reactions in a closed system determined by a single physical variable such as temperature or confining pressure. Rather we envisage even the simplest cases of metamorphism as complex reactions in multicomponent systems subject to the influence of many physical variables among which may be mentioned temperature, load pressure, fluid pressure, partial pressures of fluid components such as H2O and CO2, and so on. The system cannot be regarded as closed to some components. Moreover some petrologistsdoubt that equilibrium is commonly approached in metamorphic systems; and in proportion to such doubt there looms the possible role of kinetics in metamorphic reactions.
This report is essentially the outcome of work done at Berkeley in 1953 and 1954 by Fyfe and Verhoogen with the aid of a grant from the Office of Naval Research (Contract Nonr-222 (21)). It was intended initially to determine the extent to which kinetic effects may control metamorphic paragenesis. It soon became apparent, however, that the investigation could not be confined to a study . . .