Nuoyinhe Gr
Type Locality and Naming
Type locality is Nuoyinhe close to Delingka, Qinghai Province. Named by Fan Jiasong et al, 1962, in Yang Zhunyi et al., Geology of Qilianshan Mountain, v. 4, fasc 4, p. 137. First appeared in a 1958 manuscript by Yang Zunyi. Composed of a lower Hajier Fm (lower siltstone; upper black shale) and a higher Zhongshigong Fm (shale).
Lithology and Thickness
Clastics. Black thin-bedded limestone (in south); and siltstone to shale (in north).
Relationships and Distribution
Lower contact
Disconformable contact with the underlying Caodigou Fm of the Bayinhe Gr.
Upper contact
Overlain by the Xiahuancang Gr (Xiahuancang Fm) of early Triassic.
Regional extent
Distributed in the South Qilian Mts. and the western segment of the Central Qilian Mts., starting from the Daban Mt. in the Turgen area in the west, to the Retong Mt. in the east. Yangkang Country, Tianjun County
GeoJSON
Fossils
Zhongshigong Fm yields Plant fossils (phytolites) such as Gigantopteris sp. and Sphenopteris, and Brachiopods such as Araxathyris aff. kueichouensis, Spinomarginifera sp.. The underlying Hajier Fm has Brachiopods: Composita yangkangensis- Spinomarginifera lopingensis-Leptodus assemblage; Bryozoa: Dybowskiella sinensis-Synocladia irregularis-Stenopora linoporalineata assemblage; plus bivalve, coral and plant fossils (phytolites).
Age
Depositional setting
The Nuoyinhe Gr in the southern marine-facies region is composed mainly of limestone, less of feldspar and quartz, with a thickness of 11.7-269.6 m, yielding abundant brachiopods. In the northern part of the area, it represents a paralic deposit region.
Additional Information