Doushangou Fm
Type Locality and Naming
It was nominated by Xiang Liwen, Lin Baoyu and Nan Runshan in 1960 and published in Paleontology Atlas of Qinling in 1963. The type section is at Doushangou, Mulianqiao of Ziyang County, Shaanxi Province. The reference section is at Bajiaokou in Ziyang County, Shaanxi Province.
Synonym: (陡山沟组)
Lithology and Thickness
The formation, 138 m in thickness, consists of grey medium-to-thick-bedded sandstone, siltstone and sandy slate intercalated with black carbonaceous slate.
Relationships and Distribution
Lower contact
The conformable contact of the Doushangou Fm with the underlying Banjiuguan Fm
Upper contact
The conformable contact of the Doushangou Fm with the overlying Wujiahe Fm is observable.
Regional extent
The formation is steady in lithology, but its thickness varies as follows: westwards from the type section 257 m thick at Bajiaokou section, 327 m at Wafangdian section and merely 138 m thick at Banjiuguan section in the southern area.
GeoJSON
Fossils
The graptolite of the formation can be classified into graptolite zones as follows: the Spirograptus turriculatus zone, the Streptograptus crispus zone and the Monoclimacis griestoniensis zone.
Age
Depositional setting
Additional Information