Manquhe Formation
Type Locality and Naming
The Manquhe Formation was erected by Liu Guifang and Wang Sien in 1987. The section for the designation is in Xishan of the Gucuo Village of Sidaoban along the China-Nepal Highway from Tingri to Nyalam of Xizang. The present lexicon refers it to as lower part of the Gucuocun Gr (see the item of Gucuocun Gr).
Synonym: “Manquhe Formation” (in quote marks), Gucuocun Fm
Lithology and Thickness
Himalayan South Belt. Lower part of the Manquhe Formation is built up by yellow green thin-bedded fine sandstone with small amounts of black shale. Middle part is black shale with marl lenses, with 5 m calcareous siltstone and ferruginous nodules at the top. Upper part is gray and dark gray calcareous shale with sandstone and gray black shale with small amounts of green thin-bedded siltstone. The Manquhe Formation is 237.4 m thick.
Relationships and Distribution
Lower contact
The yellow green fine sandstone at the base of the formation is gradational with the black shale at the top of the underlying Gucuobingzhan Fm (Gucobingzhan Fm in spelling in Jurassic lexicon entry).
Upper contact
Regional extent
The present formation mainly occurs in the Gucuo and Menbu areas. It is persistent in lithology.
GeoJSON
Fossils
In the Gucuo Village, it yields ammonites Berriasella cf. grandis, B. cf. berthei, Neocomites sp., etc. and the bivalve Neilo biplicata-Pseudolimea-Eotrigonia tibetensis fauna mainly including Neilo biplicata, N. elongata, Mesosaccella simplix, Nuculana (Praesaccella) ovata, Grammatodon (Lamellelodon) gucuoensis, G. (L.) ingenitis, Entolium protentum, E. altilis, Pseudolimea globata, P. gaultina, Astarte elongata, etc.
Age
Depositional setting
It is marked by trough margin-external shelf deposition.
Additional Information