Sijiagou Fm
Type Locality and Naming
The type section is at Sijiagou in Xiehao, Wuwei, Gansu. The Sijiagou Fm was named by Mu Enzhi and Zhang Youkui in 1964.
Synonym: (斯家沟组）
Lithology and Thickness
The formation is dominated by argillaceous limestone, nodular limestone, limestone, shale, siltstone and line-grained sandstone. In the type area, the Sijiagou Fm is 397 m thick.
Relationships and Distribution
Lower contact
It rests conformably on the sandstone and fine conglomerate at the top of the Tianzhu Fm
Upper contact
It is conformably overlain by the Xiehao Fm.
Regional extent
With a persistent lithology, the Sijiagou Fm is exposed at Qiqiaogou (225 m thick), Sijiagou (397 m thick), Zhigou (490 m thick) in Xiehao, Wuwei and Shichengzi in Dajing, Gulang (32 m thick), Gansu.
GeoJSON
Fossils
The lower part yields trilobites Cyclopyge and Birmanites, and the upper yields graptolites of Orthograptus quadrimucronatus assemblage.
Age
Depositional setting
Additional Information