Research and preliminary application in metallogenic chronology of Re-Os isotope system in graphite samples.
石墨Re-Os同位素分析及其在成矿年代学中的初步运用

Re-Os analyses of graphite from the Sinian-Cambrian boundary stratum in Changshouyuan Pb-Zn deposit Jiangxi Province demonstrate the potential utility of the Re-Os system for establishing the absolute timing of metamorphism. The Re-Os age of the graphite is 424±25Ma consistent in error range with the regional magmatic zircon age of 433±9Ma, which indicates that the genesis of the graphite is associated with the regional intrusion event. Compared with the crust abundance, the graphite is significantly rich in Re and Os. The initial 187Os/188Os ratio of 1.69±0.29 indicates the graphite deriving from the organic-rich sedimentary rock. The study on the occurrence of Re and Os in the graphite demonstrates that the Re and Os are likely to occur in the fixed carbon rather than organic carbon. Though considerable further research is required to understand the Re-Os isotopic systematic of metamorphism, graphite Re-Os geochronology may provide the possibility of establishing a more comprehensive understanding of metamorphism, as well as important for the research on the metallogeny.