Toudaoqiao Fm
Type Locality and Naming
Western Middle Tianshan. The Toudaoqiao Fm was named by Gao Zhenjia et at. in 1977. The type section is near Toudaoqiao (bridge) on east bank of Koksu River Valley, southeast of Tekes County, Xinjiang Weiwuerzhu Zizhiqu (Xinjiang Uygur Autonomous Region). Lowermost formation in Tekes Gr.
Synonym: （头道桥组）
Lithology and Thickness
The Toudaoqiao Fm consists of low-grade metamorphosed marine clastic rock association. The formation is dominated by grey-green sericite chlorite-quartz schist, sericite phyllite, schistose crystalline limestone, quartz schist, sandwiched with quartzite. The formation is 2785 m thick.
Relationships and Distribution
Lower contact
Bottom is not seen. Regionally, the next older unit is the Talati Gr (PaleoProterozoic)
Upper contact
The top is in conformably overlain by the Machanggou Fm.
Regional extent
Western Middle Tianshan. It widely spreads southeast of Tekes County, where it is exposed completely and the stratigraphic sequence is clear.
GeoJSON
Fossils