The objectives of this research on pelitic metamorphic rocks at SMU are: (1) to work out stability relations of minerals, and (2) to determine metamorphic conditions and history of a number of pelitic metamorphic terrances. In addition to finishing the Picuris and ferric-ferrous study on staurolite during 1989, Holdaway will: (1) complete the study of low-pressure metamorphism in Maine; (2) complete the determination of Fe- cordierite stability; and (3) undertake a study of possible staurolite nonideality and retrieve a self-consistent set of thermodynamic data-set that promises to provide useful constraints on pressure, temperature, and fluid composition in petitic metamorphic rocks. This will add to our understanding of the conditions under which clays (shales, when lithified) are buried, heated, and become schists.