Tunlonggongba Fm
Type Locality and Naming
The type section is located in the West Trench of the Tunlonggongba area, Duoma Region, Ritu County, Tibet.It was named by Wang Yujing and Mu Xinan in 1980.
Synonym: Cainaha Fm
Lithology and Thickness
Clastics and Limestone. Grey-green sandstone, black slate and dark-grey limestone. Thickness is over 500 m.
Relationships and Distribution
Lower contact
Conformable contact with the underlying Qudi Fm
Upper contact
Seems to be in disconformable contact with the overlying Longge Fm
Regional extent
Distributed extensively in the Duoma Region of the Ritu County of Tibet. The Tunlonggongba Fm that is distributed in the Mushirebuka area in the southern part of Qiangtang Region used to be known separately as the Cainaha Fm which is composed mainly of carbonate, intercalated with a small amount of sandstone, as well as some basaltic strata. Its thickness is increasing easterly to reach as great as 2200 m.
GeoJSON
Fossils
Yields fairly abundant marine animal fossils, with its lower part yielding Brachiopods of the Costiferina-Juresania assemblage and with its upper part yielding the Paraderbyia duomaensis-Jipuproductus assemblage. The Fusulinids belongs to the Monodiexodina fauna. There occur also two Coral assemblages, namely the Lytvolasma assemblage and the Polythecalis-Chusenophyllum assemblage.
Age
Depositional setting
Additional Information
GeoJSON estimate by Longgang Ye and Yuyin Li (Chengdu Univ. Tech. students)