Yeba Fm
Type Locality and Naming
South Lhasa Block – LhasaCity. The Yeba Formation was erected by Wang Naiwen et al in 1983. The section for the designation is from Qulong to Yebagou of the Dagze County of Xizang.
Lithology and Thickness
The Yeba Formation is dominated by variegated tuff and slate, which is different from the Paleogene Linzizong Fm dominated by massive volcanic rocks. Lower part is built up by gray white and yellow gray quartz sandstone, slate, volcanic breccia and gray, gray green and gray white tuff, volcanic breccia and andesite. Upper part is gray white and gray green phyllite, shale with rhyolite and purple gray and gray green andesite, volcanic breccia and tuff. The base of the formation is built up by gray, green and grayish white tuff, volcanic breccia and andesite. The Yeba Formation is 3000-10000 m thick.
Relationships and Distribution
Lower contact
The tuff-breccia-volcanic base lies conformably on the underlying Liuwu Fm consisting of limestone bearing siliceous lumps.
Upper contact
The overlying formation is unknown in the type area. Regionally it is probably in unconformable contact with the Paleogene Linbuzong Fm
Regional extent
The present formation is mainly distributed in the Qulong and Yebagou area of the Dagze County. It is persistent in lithology.
GeoJSON
Fossils
None listed
Age
Depositional setting
Additional Information