This study is to document the scale of thermal, fluid- circulation, and metasomatic effects around a distinctively volatile-and rare-element-rich synmetamorphic graite-the 1.7 Ga Harney Peak Granite in the Black Hills, South Dakota. The primary data base will consist of 40 samples of pelitic rocks ranging in metamorphic grade from the biotite through the sillimanite zone. The sample traverse will be confined to a single stratigraphic unit, and will extend 40 km from the granite contact. Major-,minor-, and trace-element chemistry and 18O will be determined on each sample, along with estimates of P-T paths. Selected samples will be submitted for thermochronometry using 40Ar/39Ar and U-Pb-Th (monazite) techniques, and fluid inclusion compositions and trapping conditions will be evaluated using microthermometry and laser-ablation ICP-MS.
