Shifang Gr
Type Locality and Naming
The type section is located Mingbaogou - Lingjiang area, and the reference section is located at Mingbaogou, northwestern Wenxian County of Gansu Provence. It was named by Ye Maoquam and others in 1960, and was published in 1976 by Qinfeng and Gan Yiyan.
Lithology and Thickness
Slate. The Group is dominated by dark greyish sandy slate intercalated with fine-grained sandstone rich in organic materials. The middle and upper parts of the Group contain several beds of siliceous conglomerates and pebbly coarse-grained sandstone. Limestone is rare and is only seen in the upper part of the Group in Mingbaogou where it is characterized by nodular limestone and sandy limestone. The Group is 925-1550 m thick.
Relationships and Distribution
Lower contact
The Group rests disconformably or with an angular unconformably on the Gangou Fm of Lower Cambrian.
Upper contact
The formation terminates with a disconformably to the Xigou Fm, which has a basal siliceous breccia.
Regional extent
GeoJSON
Fossils
The fossils mainly developed in the upper part of the Group are
corals: Squameofavosites bohemicus, Favosites cf. parastriatoporoides, Aulacophyllum sp.,
brachiopods: Protathyris sibirica, Howellella laeviplicata labilis.
Age
Depositional setting
Additional Information