Longhai Fm
Type Locality and Naming
It was named by the Group on Stratigraphy of Western Yunnan Party under the Institute of Geology, Academy of Sciences of China in 1965, and was first cited publicly by Yin Jixiang, Fang Zhongjing in 1973. The naming section is located in the area of Mengga till Longhai 26 km southwest of the Luxi County Town, Yunnan Province.
Synonym: （龙海组）
Lithology and Thickness
Composed mainly of yellow calcareous shales, with its upper part being composed of yellow ad yellow-green shales, sandy shales and siltstones, with no top part having been found, and with a thickness of 200 m.
Relationships and Distribution
Lower contact
It conformably underlies the Liuwan Fm.
Upper contact
No top has been found. But in the Longkan section the present formation is in a disconformable contact with the overlying Longkan Fm, with a thickness of 196.3 m. Schematic strat column in previous "red Chinese Lexicon" had indicated that the next younger unit is a Nongkan Fm of Cretaceous age (not in current Lexicon).
Regional extent
Longhiazi and Longkan of Luxi County, in the vicinity of Wanding County Town, the Datian Pass of Longling County, Shuifangjie of Yongde County until the Gengjie of Changning County.
GeoJSON
Fossils
It yields bivalve fossils as represented by Camptonectes longhaikensis, Placuneopsis radiata, Ostrea (Liostrea) uncata, Modiolus lassus, as well as Brachiopod fossils. In the areas of Longkan and Mengga the formation yields also fresh-water bivalves as represented by Undulatula (Ancyrunio) yunnanensis, Psilunio (Phorunio) thailandicus, Neomiodo khoratensis.
Age
Depositional setting
Additional Information