Lianghekou Fm
Type Locality and Naming
The type section is located at Lianghekou, Yajiang County, Sichuan. It was named by Li Yueyan in 1940.
Synonym: It was firstly named as “Lianghekou Shale”. And then it was revised as “Lianghekou Formation” by the District Geological Survey Group of the Sichuan Geology and Mineral Bureau in 1984. Here it was suggested that it should be new name for this formation in the Luhuo area (Zhang Shunxin and Yang Zunyi).
Lithology and Thickness
It is gray and dark gray metamorphic quartz sandstone, feldspar quartz sandstone and interbedded with the silty slate and carbonaceous slate. And there are many meta-sandstones in the upper and lower parts of this formation. In the Luhuo area, it is dominated by sandstones and conglomerates. Its thickness is 2000 to 4000 m.
Relationships and Distribution
Lower contact
This formation is conformable in contact to the underlying Waduo Fm
Upper contact
Next younger regional unit is the Yajiang Fm of late Norian-Rhaetian (also same Yajiang county as this formation).
Regional extent
This formation is distributed in the areas of Yajiang and Xinlong, Sichuan.
GeoJSON
Fossils
Bivalves: Halobia pluriradiata, H. Fallax, H. cf. salinarum, Pergamidia eumenea, P. attalea and so on. Plants: Pterophyllum yunnanensis, Anomozamites loczyi, Taeniopteris stenophylla.
Age
Depositional setting
In the Luhuo area, the facies became delta deposits.
Additional Information