Isotopic Heterogeneity of Carbon in Metamorphic Fluid

摘要

The petrological evidence for infiltration of the reduced fluid into metamorphic rocks during metamor- phism was provided using methods of phase consis- tence, thermal degassing, electrochemistry, electron microscopy, and computer-aided physicochemical modeling. These testimonies include the reduced state of minerals and gas inclusions therein, some reaction structures, prevalence of ferrous ion in minerals, and occurrence of fine graphite or fine-dispersed carbon- aceous phase in metamorphic rocks. It was estab- lished that the formation of reaction structures, crystal- lization of fine-dispersed graphite from fluid, and entrapment of reduced fluid by growing minerals took place at the retrograde metamorphic stage. This work is aimed at the estimation of isotopic heterogene- ity or homogeneity of carbon contained in this reduced fluid and elucidation of its origin.