Longdanyan Fm
Type Locality and Naming
It was named by Jin Chuntai et al. (1989). The type section is located at the roadside from Yuanyangyan to Longdanxi, east of Erlangshan Mt. in western Sichuan Province.
Synonym: (龙胆岩组)
Lithology and Thickness
It is composed of gray and dark gray lenticular limestone, dolomitic argillaceous limestone and calcareous mudstone. It is 88 m in thickness in the type locality.
Relationships and Distribution
Lower contact
It rests conformably on the underlying Luoquanwan Fm
Upper contact
It rests conformably below the overlying Changyanzi Fm
Regional extent
The exposures of the formation are observed in the area of Erlangshan Mt. in western Sichuan Province.
GeoJSON
Fossils
The main fossils contained are as follows: brachiopods Levenea, Qianomena, Striispirifer, Nalivkinia; trilobite Encrinuroides; tetracoralla Brachyelasma and abundant conodonts Distomodus kentuckyensis, Paracordylodus guizhouensis, Ligonodina kentuckyensis etc.
Age
Depositional setting
Additional Information