Pulai Fm
Type Locality and Naming
The type section is located at Dangduogou, 24 km northwest of Diebu County, Gansu. It was named by Cao Xuanduo et al. in 1987.
Lithology and Thickness
It is dominated by fine-grained clastic rock.
Lower member, 53.3 m thick, is mainly black silty shale intercalated with thin- to medium-bedded micrite, with a top bed of more than 10 m of massive sparry algae-bearing sandy bioclastic limestone.
Upper member, 214.2 m thick, is mainly black to gray carbonate-bearing shale intercalated with a few thin-bedded lenses of sandy micrite.
Relationships and Distribution
Lower contact
It conformably overlies on the Xiawuna Fm.
Upper contact
It conformably underlies the Cakuohe Fm.
Regional extent
GeoJSON
Fossils
Lower member contains abundant small size brachiopod and solitary coral and is characterized by tentaculites Nowakia otomari acme zone.
Upper member - lower part mainly yields Nowakia postotomari-Wedekindella clarkei assemblage zone, and the upper part has the coral Grypophyllum mackenziense-Temnophyllum longiseptatum assemblage zone.
Conodont Icriodus symmetricus and tentaculites Striatostyliolina raristriata appear on the top.
Age
Depositional setting
It is interpreted as a neritic shelf to basin facies.
Additional Information