Qiaotingzi Fm
Type Locality and Naming
The type section is at Qiaotingzi in Shuangfeng, Hunan. The Qiaotingzi Fm is derived from the Qiaotingzi Series proposed by Tian Qijun (C.C. Tien) in 1933, and was published by Central-South Compiling Group for Regional Stratigraphic Scale (1974). Jin Yuqin et al. (1964) restudied the Qiaotingzi Series, and renamed it the Qiaotingzi Fm. At the same time, they suggested that the type section is incomplete due to the covering of the Quaternary; but at Shimenkou and Jiutang reservoir in Qidong County its top part is exposed completely, and at Nanshichong in Xiangtaoyuan, Taojiang County, and Hongqi reservoir in Qidong its base is exposed completely.
Synonym: (桥亭子组)
Lithology and Thickness
The Qiaotingzi Fm is dominated by gray, yellowish green slaty shale intercalated with silty shale or sandstone. It has a persistent horizon and a thickness of 170-290 m.
Relationships and Distribution
Lower contact
At Shimenkou in Qidong County and Xiangtaoyuan in Taojiang County, it rests conformably on the dark gray laminated shale of the Baishuixi Fm
Upper contact
It is conformably overlain by the dark green silty shale at the base of the Yanxi Fm.
GeoJSON
Fossils
This stratigraphic unit includes five graptolite zones, in ascending order, Tetragraptus approximatus zone, Didymograptus deflexus zone, Didymograptus abnormis zone, Cardiograptus amplus zone and a part of Undulograptus austrodentatus zone.
Age
Depositional setting
Additional Information