XiawuchuboMember Fm
Type Locality and Naming
The Xiawuchubo Formation was erected by Wan Xiaoqiao in 1985. The section for the designation is at the Xiawuchubogou on the southern side of Zongshan about 250 m southeast of the Gamba County, Xizang. Wan Xiaoqiao et al. (2000) renamed it as the Lower Member (or Xiawuchubo Member) of the Gambacunkou Fm (see the item of Gambacunkou Fm).
Synonym: Xiawuchubo Member
Lithology and Thickness
The Xiawuchubo Formation (member) is mainly represented by yellowish green clayey shale and thin-bedded marl interbedded with yellowish green shale, bearing marl lenses, yellowish green shale with thin-bedded marl and thin-bedded micrite. The Xiawuchubo Formation is 98.81 m thick.
Relationships and Distribution
Lower contact
The base of the formation is gradational with black shale of the underlying Lengqingre Fm.
Upper contact
Gradational relationship with the overlying JiubaoMember Fm.
Regional extent
The present formation (member) occurs in the Gamba-Tingri basin. It is persistent in lithology.
GeoJSON
Fossils
In the Gamba area, it yields abundant bivalves Camptonectes virgatus, Pycnodote (Phygraea) cf. vesiculosa, P. (P.) cf. pseudovesicularis, Bakevellia subpseudorotrata, Phelopteria boeckhi, Inoceramus (Cataceranus) sp., I. (Endocostea) haydeni, I. (s.l.) cf. crippsi, I. (s.l.) flatus, etc.; and Foraminifera Praeglobotruncana helvetica, Hedbergella crass, H. orectos, H. protsdownensis, H. murphi, Heterohelix globulosa, H. reussi, Valvulineria parva, etc.
Age
Depositional setting
It belongs to normal neritic facies
Additional Information