Physicochemical conditions and timing of rodingite formation: evidence from rodingite-hosted fluid inclusions in the JM Asbestos mine, Asbestos, Québec

摘要: Fluid inclusions and geological relationships indicate that rodingite formation in the Asbestos ophiolite, Quebec, occurred two, or possibly three, separate episodes during thrusting of ophiolite onto Laurentian margin, it involved three fluids. The first episode rodingitization, which affected diorite, at temperatures between 290 360°C pressures 2.5 to 4.5 kbar, second episode, granite slate, 325 400°C less than 3 kbar. fluids responsible for these alteration were moderately strongly saline (~1.5 6.3 m eq. NaCl), rich divalent cations contained appreciable methane. A possible third is suggested by primary fluid vesuvianite-rich bodies secondary other types rodingite, with significantly lower trapping temperatures, salinity methane content. association aqueous hydrocarbon-rich containing CH4 higher order alkanes, but no CO2, suggests former originated from serpentinites. similarities composition all rock had already been thrust slates when rodingitization occurred.