The Zhangbaling Group in eastern Anhui is located in the southern part of the Tan-Lu fault zone. It is one of the most important metamorphic blocks between the Dabie orogenic belt and the Sulu orogenic belt, and the tectonic position is very unique and important. Previous studies mainly focus on tectonic geology, chronology and petrogeochemistry. The study of main metamorphic conditions, rock units and time series are relatively indistinct. This paper conducts a detailed research on peak metamorphic conditions, lithology characteristic and rock unit division on the basic of regional metamorphic petrology, lithofacies thermodynamics and chronology studies. Combined with muscovite thermometer and previous studies, the results of peak metamorphic temperature of unite-Ⅰ and unite-Ⅱ are T = 368 ℃～494 ℃ and T = 331 ℃～394 ℃, respectively. It shows that Zhangbaling Group mainly gone through greenschist-epidote amphibolite facies. The study of LA-ICP-MS zircon U-Pb reveals the crystallization age of unit-Ⅰ and unit-Ⅱ are 749±8 Ma～738±8 Ma and 738±9 Ma and basically consistent with previous studies. However, the clastic age of unit-Ⅲ is ranging from 908±29 Ma to 685±30 Ma. The source of unit-Ⅲ is relatively single and sedimentary provenance is mainly from unit-Ⅰ and unit-Ⅱ. The maximum sedimentary age is 685±30 Ma. The sedimentary time should belong to Neoproterozoic, and the source of sedimentary material is mainly from Yangtze plat. According to the above research, we divide Zhangbaling Group into three units from bottom to top. Unit-Ⅰ, unit-Ⅱ and unit-Ⅲ are respectively composed of quartz-feldspar schist mica quartz schist and a small amount of metabase, phyllite, marble and a small number of schist. The result of this paper provides a certain petrological support for understanding the convergence of the North China plate and the Yangtze plate along the Tan-Lu fault. The Zhangbaling Group does not experience high-pressure, low-temperature blue schist facies metamorphism.
Yang Genshan Shi Jinfei Shi Yonghong Wang Juan Li Yibin. Evaluation of the main stage metamorphism temperature of the Zhangbaling Group in eastern Anhui and its structural framework[J]. Chinese Journal of Geology, 2019, 54(3): 736-762.