Rilagou Fm
Type Locality and Naming
Sichuan Diaoduan and Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (1982) collectively referred to the Early Triassic Induan-Olenekian strata in western Sichuan as the Boatigou Fm. In 1991, Sichuan Bureau of Geology and Mineral Resources separated the upper strata of the Botzigou Fm (Bocigou Fm) and named it Rilagou Fm, which was determined to be the Early Triassic Olenekian.
Synonym:
Lithology and Thickness
It is gray with purplish red, grayish green, brown slate, crystalline limestone and a little siltstone. Purplish red or brown is the striking mark of this group, and it is the top and bottom boundary mark of this group.
Relationships and Distribution
Lower contact
It is conformable with the underlying Bocigou Fm
Upper contact
Pseudo-conformable with the overlying Zagashan Fm
Regional extent
The lithology is stable and the thickness is generally 30 to 100 m. Distributing in Sichuan Luhuo, Songpan, New Jin, Rang Tang area. In the area of Songpan Gold Panning Gou, the formation overlaps over the Permian system.
GeoJSON
Fossils
It contains conodonts Neospathodus waageni, N. collinsoni, N. timorensis, Neogondolella jubata and Gladigondolella tethydis.
Age
Depositional setting
It is interpreted as warm, normal marine deposits.
Additional Information