摘要：200 cm−1) D-peak at ~1345 cm−1 (defect peak), which is much lower than the O-peak at ~1595 cm−1 (ordered peak), indicating a metamorphic temperature of zeolite facies or lower than 250 °C.In addition, the stable carbon isotopic compositions (δ13C values) of the CMVs, ranging from −23.4 to −26.4‰, are very similar to that of the kerogen collected from the Late Triassic Xujiahe Formation in Sichuan Basin.Given the data at which it may be formed, the Xujiahe Formation is the most likely origin of CMs for the CMVs, and it seems that some CMVs in the fault zone were crushed and intruded into the voids during coseismic events, possibly driven by an enhanced pore fluid pressure.Since graphitization is suggested as an indicator of transient frictional heating in this area, our study providing a reference data set of CMs would help future CM-rich fault-zone research to retrieve seismic signatures presumably occurring in the Longmen Shan fault zone belt.
关键词：Carbonaceous material vein; Origin; Formation; Wenchuan earthquake fault zone
