摘要
Blueschist accompanied by pelitic schist expose along the Xinlin-Xiguitu fault in the Toudaoqiao area, northeastern China. In this paper, the blueschist is systematically studied on the petrography and mineral chemistry. The amphiboles in the blueschist are zoned from winchite core to magnesioriebeckite/glaucophane rim to winchite outermost rim. The peak metamorphic conditions are defined by the mineral assemblage of magnesioriebeckite/glaucophane, epidote, high-Si phengite（Si〈7.1）, chlorite, albite, hematite and quartz, indicating an epidote-blueschist facies metamorphism. The P-T conditions are estimated as T=350–400 ℃ and P=10-12 kbar. The occurrence of the blueschist along the Xinlin-Xiguitu fault strongly suggests the fault is the suture between the Ergun and the Xing＇an blocks situated in the eastern portions of the Central Asia Orogenic Belt（CAOB）.
Blueschist accompanied by pelitic schist expose along the Xinlin-Xiguitu fault in the Toudaoqiao area, northeastern China. In this paper, the blueschist is systematically studied on the petrography and mineral chemistry. The amphiboles in the blueschist are zoned from winchite core to magnesioriebeckite/glaucophane rim to winchite outermost rim. The peak metamorphic conditions are defined by the mineral assemblage of magnesioriebeckite/glaucophane, epidote, high-Si phengite（Si〈7.1）, chlorite, albite, hematite and quartz, indicating an epidote-blueschist facies metamorphism. The P-T conditions are estimated as T=350–400 ℃ and P=10-12 kbar. The occurrence of the blueschist along the Xinlin-Xiguitu fault strongly suggests the fault is the suture between the Ergun and the Xing＇an blocks situated in the eastern portions of the Central Asia Orogenic Belt（CAOB）.
基金
supported by 973 program (No.2013CB429802) to Y.J.Liu
the National Natural Science Foundation of China (Grant 41302175) to W.M.Li
Jilin University and JSPS Grant-in-Aid for Scientific Research (Nos.17340149, 24340124) to A.Takasu, Shimane University, Japan
