Daposhan Fm
Type Locality and Naming
Northeast Liaoning. The Daposhan Fm was named by the No.9 Party of Geology, Liaoning Bu-reau of Geology and Mineral Resources in 1989. The type section is in Wenjiatun Village, Xiafeidi Township, Kaiyuan County, Liaoning Province. It is the lower formation of the Sanchazi Gr.
Synonym: （大迫山组）
Lithology and Thickness
The Daposhan Fm is composed of littoral sediments of supratidal-intertidal zone, which experienced slight metamorphism. Lower part is mainly of clastic rock, medium- to thick-bedded pebbly or pebble-free metamorphosed feldspar-quartz sandstone. Upper part consists entirely of medium-thick bedded fine-crystalline dolomite (either containing quartz sand clasts or siliceous). The formation is 782 m thick.
Relationships and Distribution
Lower contact
It is unconformably rests on the underlying metamorphosed Archean complex.
Upper contact
It is overlain by the Kangzhuangzi Fm (the middle formation of the Sanchazi Gr).
Regional extent
Northeast Liaoning. It is widely distributed in the Fanhe region and is more stable in lithological character, but changeable in thickness, for example it is seriously thinned at Sanchazi area, Tieling County, where it is thinned to 260 m thick only.
GeoJSON
Fossils
The stromatolites in it are: Xiayingella xiayingensis, Gruneria cf. biwabikia, Kussiella tuanshanxi
Age
Depositional setting
Littoral sediments of supratidal-intertidal zone
Additional Information