Stable isotope study of coexisting metamorphic minerals from the Esplanade Range, British Columbia

摘要: Hydrogen, carbon, and oxygen isotope analyses have been made of coexisting minerals from regionally metamorphosed rocks the Esplanade Range, British Columbia. Regularities in hydrogen compositions imply attainment isotopic equilibrium. Temperatures, determined on basis fractionations between quartz ilmenite (magnetite), range 460°C (biotite-chloritoid zone) to 540°C (staurolite-biotite are good agreement with temperatures estimated comparison experimental phase equilibria mineral assemblages. The data comparable results obtained by other workers studying Barrovian-type metamorphism different areas. relatively narrow ranges δO 18 values for δD biotite hornblende a wide protoliths suggest either that there was communication these or they exchanged large reservoir having fixed ratios. A single orthoamphibolite, however, has show it not rocks. carbonates Range unusually enriched C 13 relative similar metamorphic localities. Values δC become more positive increasing grade −2.5 +9.8.