Qujing Fm
Type Locality and Naming
It was named by Grabau A.W. in 1923 based on an uncompleted section at East Hill of Qujing. Sun Y.C. (1945) suggested a reference section at Panxi Town of Mile County, along Nanpanjiang River (103o06'E, 24o16'N), for which Gu C.V. made a detailed description in 1949.
Synonym: Kütsing Gr
[Figure Location map of Itate Fm (Dy), Qujing Fm (Dq), and Datang Gr (Cd, Carboniferous).]
Lithology and Thickness
Limestone. This formation, maximum thickness up to 1000 m, is mainly composed of gray medium- to thick-bedded limestone, intercalated with clayey limestone, shelly limestone, dolomite and dolomitic limestone. Some layered or lenticular carbonates formed by accumulation of transported organisms are partly developed.
[Figure Outcrops of Qujing Fm in the lectstratotype locality of Panxi. A-semi-nodular bioclastic limestone of upper part of Qujing Fm. B-Close-up of dolomite. C-Massive stromatoporoid limestone. D-shelly bed consisting of brachiopod Stringocephlus. Length of hammer 24 cm and pencil 16 cm for scale.]
Relationships and Distribution
Lower contact
It rests conformably on the Haikou Fm.
Upper contact
Conformable contact with overlying Itate Fm, or locally (Chaotong) with the Zaijiehan Fm
Regional extent
The formation is widely distributed in the Qujing-Zhanyi area, Nanpanjian valley, Kunming-Wuding area and northeast of Yunnan. In the Nanpanjian valley between Huaning and Mile, this Formation is best developed and is dominated by carbonate deposits with maximum thickness up to 1000 m. In Qujing and Wuding areas it contains shales and sandstones, and the thickness decreases to 30-180 m. The Qujing Fm of Qingmen section at northeastern Yunnan comprises, up to 456 m thick, bioclastic limestone, dolomitic limestone with few shale, sandstone and argillaceous limestone.
GeoJSON
Fossils
This formation contains brachiopods Stringocephalus obesus, S. burtini, Bornhardtina sp.; Corals Temnophyllum poshiense, T. waltheri, Neospongophyllum tabulatum; Stromatoporoids and ostracods.
Age
Depositional setting
It is suggested as an open platform environment
Additional Information