Kalpintag Fm
Type Locality and Naming
The Formation was named by the 13th Party of Ministry of Geolgy in 1955 and published by Zhang Ridong et al in 1959. The type section is approximately 10 km northwest of the Kalpin County in the Xinjiang) Uygur Zizhiqu. The reference section is at Dawuan'gou, 20 km northwest of Yingan Village, Kalpin County.
Synonym: (柯坪塔格组); Kalpintake Fm, Kelpintag Fm
Lithology and Thickness
The formation is dominated by interbeds of yellow green, gray green and purplish micritic sandstone with quartzose siltstone, pelite and silty pelite, with yellow gray conglomerate at the base; the pelitic siltstone may contain muddy gravels or micritic cross-beds.
Relationships and Distribution
Lower contact
The Kalpintag Fm, 353 m in thickness, is disconformably underlain by the Yingan Fm of late Ordovician.
Upper contact
It is conformably overlain by the Tataertag Fm.
Regional extent
In the area of Kalpin and at Halchak Mt.-Altemeishibulak, north of Lop Nur. at Xiaohaizi Reservoir in Bachu (Maralwexi) County, it is changed into purplish red colour and is 107 m in thickness. At the type section area in Kalpin, it is 445 m thick. Based on geophysical data, the formation is very widely distributed underground.
GeoJSON
Fossils
It is rich in fossils in the upper part, yielding the graptolites Normalograptus tangshanensis, N. tamariscus linearis, N. cf. tamariscus, Climacograptus nanjiangensis, C. angustus, C. minutus, Petalolithus ataum; bivalves Nuculites kalpinensis, Praectenodonta kalpiensis, Palaeoneilo sp.; gastropods Bucanopsis sp., Planitrochus sp., Eatomaria sp.；trilobites Leonaspis sp., Encrinuroides sp.; chitinozoa Conochitina sp., etc.
Age
Depositional setting
It belongs to neritic-littoral facies according to the fossils and depositional characteristics.
Additional Information