Xiazhuang Fm
Type Locality and Naming
Xie Jiarong erected the Xiazhuang series in 1933. The reference section 1 is from Chaoshan to Liutaizhuang of the Fengtai District of Beijing (member 1); the reference section 2 is at Xishanliang of Xiazhuang of the Fengtai District of Beijing (member 2); and the reference section 3 is from the Dafu Village to the Shawo reservoir (member 3).
Lithology and Thickness
The Xiazhuang Formation is divided into three members. The lower member is dominated by yellow brown siltstone and shale with a small amount of conglomerate; the middle member by yellow green and gray white mudstone and sandstone with gypsum; and the upper member is composed of gray yellow and purple brown conglomerate, sandstone and mudstone. It is 597 m thick.
Relationships and Distribution
Lower contact
The conformable base of the formation marked by yellow brown gravel-bearing grit is distinguished from the underlying Lushangfen Fm marked by dark gray mudstone interbedded with yellow brown siltstone.
Upper contact
The unconformable top is bounded by the appearance of purple and yellow brown sandy conglomerate at the base of the Paleogene Changxindian Fm.
Regional extent
The present formation occurs in the Chaoyangshan-Liutaizhuang and Xiazhuang- Dafuzhuang-Xidian hilly areas of the Western Hills of Beijing.
GeoJSON
Fossils
The formation yields bivalves Xishanoconcha xiazhuangensis, X. yanshanensis, Sphaerium anderssoni, X. yanbianense; estherias Yanjiestheria yunnanensis, Neodiestheria xiazhuangenses; ostracods Cypridea tera, C. acclinia, C. yaojiaensis, Candona orientalis, Candoniella minuta, Candona candida, Cyprinotus xishanensis; floras Cissites jiusiensis, Sagenopteriis jinsiensis; sporopollen grains Cicatricosisporites australiensis, Lycopodiumsporites marginatus, Cyathidites australis, Tricolpites sp. and Retitricolpites sp.
Age
Depositional setting
It belongs to fluvial-lacustrine deposition.
Additional Information