Dabalao Fm
Type Locality and Naming
Himalayas. The type section is at Dabalao to the highest peak (elevation 6004 m) in Xialazi Mount in the south part of Polin, Zanda County, southwestern Tibet. The Dabalao Fm is derived from the Lower Dabalao Fm and Upper Dabalao Fm of Liang Dingyi et al. (1991).
Before the Lower Dabalao Fm and Upper Dabalao Fm were published, Nie Zetong (1990) had used these two terms.
Synonym: (达巴劳组）
Lithology and Thickness
In the type section, the Dabalao Fm is divided into two parts. Lower part, equivalent to the Lower Dabalao Fm, is composed of 366 m thick sequence of brownish yellow quartz sandstone, quartz greywacke, calcareous sandstone. Upper part, about 345 m thick, is composed of feldspar quartz sandstone, calcareous sandstone intercalated with mudstone and argillaceous limestone.
Relationships and Distribution
Lower contact
The formation rests conformably on the metamorphosed sandstone of the Duanlongri Fm (not in lexicon); next older regional unit is the Rouqiecun Gr of Late Cambrian.
Upper contact
Regional extent
It is only exposed in Dabalao district.
GeoJSON
Fossils
It yields abundant trilobites of Isoteloides-Hystricurus assemblage, cephalopods of Manchuroceras-Protocycloceras assemblage and trace fossils Rhycodes, Fucosopsis and Quebecichnus in the lower part, and contains cephalopods Protocycloceras sp., Endoceras sp., “Cameroceras" sp. in the upper part.
Age
Depositional setting
Additional Information