Luzhijiang Fm
Type Locality and Naming
East-central Yunnan. The Luzhijiang Fm was named by the No.303 Party of Yunnan Metallurgical Geological Prospecting Corporation in 1956 in Luzhijiang region, Yimen, Yunnan Province. The reference section is in Manpo-Lujiacun, Wuding County, Yunnan Province. It is a middle formation in the Douchuan Gr.
Synonym: （绿枝江组）
Lithology and Thickness
The Luzhijiang Fm is dominated by blue-grey, greyish medium- to thick-bedded and massive stromatolite-bearing dolomite, sandwiched with sericite slate, muddy limestone, limestone, siliceous limestone and dolomite. The Luzhijiang Fm is 1500 m thick.
Relationships and Distribution
Lower contact
The base is in conformable contact with the underlying Etouchang Fm.
Upper contact
The top is disconformably overlain by the Liubatang Fm (Dayinpan Fm). Schematic stratigraphic column has next higher regional unit as the Kunyang Gr (of which the Huangcaoling Fm is the lowest entry in current Lexicon; and implying the Jixianian (Ectasian) is a major hiatus between.).
Regional extent
East-central Yunnan. The formation is exposed mainly in Yimen and Eshan counties, central Yunnan Province
GeoJSON
Fossils
It bears stromatolite and microplants. The major stromatolite taxa Conophyton garganicum, Gymnosolen confragosus, Jacutophyton f., Jurusania f., Pseudogymnosolen f., Microstylus f., Cryptozoon f.
Age
Depositional setting
Additional Information
In the Dongchuan district of eastern Yunnan Province, the formation is termed Qinglongshan Fm. The stratigraphic position of these two formations is equivalent, but differ in lithological character; therefore, the Yunnan Bureau of Geology and Mineral Resources (1996) considered that the Qinglongshan Fm is a synonym of the Luzhijiang Fm.