Dayer Fm
Type Locality and Naming
It was named by Zhao Xijin in 1985. The naming section is located 5 km east of Changdu County Town (=Chamdo County Town) in the area of Sichuan Bridge on the Zaqu River in the vicinity of Dayi to the Guobuka Village on the western slope of the Damala Mts.
Synonym: （大野组）
Lithology and Thickness
Representing a set of purple sandstone and mudstone. Lower part being composed of purple and dark-purple silty mudstones, intercalated with purple sandstone and grey-green pebble-bearing siltstone. Upper part is composed essentially of grey-violet and purple sandstones, intercalated with purple silty mudstone and conglomerate lenses. It is 1574 m thick.
Relationships and Distribution
Lower contact
It is in a disconformable contact with the underlying Duogaila Fm (= upper unit of Bagung Fm of late Triassic)
Upper contact
Regionally, the schematic strat column indicates the next younger unit as Dapuka Fm
Regional extent
The formation is distributed in the areas of Chamdo, Chaya, Mongkang and Leiwuqi of eastern Tibet.
GeoJSON
Fossils
Its lower part yields reptiles Lufengosaurus changduensis, Megalosaurus tibetensis, and Ickthyosaurus and fish fossil Hybodus changduensis, indicating the connection of it with sea water.
Age
Depositional setting
Additional Information