Zhangkezhai Fm
Type Locality and Naming
It was named by the No. 16 Geological Party under the Geological Bureau of Yunnan Province in 1966. The naming locality is situated at the Zhangkezhai Village 18 km west of the Pu’er County town, Yunnan Province, with the section in the Nanbangpo area of Dehua region, Pu’er County serving as its reference section.
Lithology and Thickness
Lower part is composed mainly of purple and grey-violet mudstones, siltstones and fine-grained sandstones, intercalated with yellow and grey-green mudstones and siltstones, with its basal part consisting of lime-conglomerates and sandy conglomerates. Middle part consists of brown-red and violet massive mudstones and silty mudstones, intercalated with yellow-green and grey mudstones, siltstones and fine-grained sandstones. Upper part is thick alternating layers of grey-yellow, violet-grey and grey fine- to medium-grained sandstones in association with purple and violet mudstones and siltstones, with the sandstones containing pebbles locally. Its total thickness is of 1096 m.
Relationships and Distribution
Lower contact
It is in a disconformable contact with the underlying Dapingzhang Fm (column TJ51).
Upper contact
Coeval with sandy claystone of Yangjiang Fm in same region. In Pu'er graphic column, next younger unit had been indicated as early-Middle Jurassic clayey sandstone of Huekalzuo Fm.
Regional extent
The formation is distributed in the Jinggu, Pu’er, Simao and Mengla county regions, with its lithology being consistent from region to region, but with increase of the basal sandy conglomerate in thickness (600 m) in the Xiaohewan area of Jinggu County. And there are greater variations in the total thickness of the formation, being in a range from tens of meters to 1600 meters.
GeoJSON
Fossils
Its lower part yields clam shrimps such as Palaeolimnadia diannanensis, P. longyinensis and P. longmenshanensis; bivalves such as Pseudocardinia sibireconchiformis and P. khadjakalanensis.
Age
Depositional setting
Additional Information
Bureau of Geology and Mineral Resources of Yunnan Province (1996) abandoned the Zhangkezhai Formation for its ambiguous definition and chaotic citations.