Shinagan Gr
Type Locality and Naming
Southeast-central Inner Mongolia (north of Yellow River loop). The Shinagan Gr was named by Sun Jianchu (Sun, C. C.) in 1934. The type locality is the Shinagan Village, 18 km north of Shetai Town, Urad-Qianqi, Inner Mongolia.
Synonym: （石纳干组）
Lithology and Thickness
The Shinagan Gr is composed of a sedimentary association dominated by carbonate rock. Lower part is quartz sandstone, sandstone and shale. Upper part is dominated by chert-banded dolomite and siliceous dolomitic limestone, intercalated with Mn-bearing limestone and bearing stromatolites. The Shinagan Gr 1000 m thick
Relationships and Distribution
Lower contact
It probably has an unconformable contact with the underlying Zhartaishan Gr, although no direct overlying strata has been seen, except for Quaternary cover. It is in unconformable contact with the underlying Wulashan Gr of Neoarchean Erathem.
Upper contact
Schematic stratigraphic section indicates the next younger regional unit is Middle Cambrian.
Regional extent
Southeast-central Inner Mongolia (north of Yellow River loop) to Hebei. It is best exposed in Shaotou Mountain and surrounding Shanheila, Urad Qianqi, Inner Mongolia. The group is sporadically distributed also in Wuyuan, Guyang, Wuchuan, Qahar Youyi Houqi, Inner Morgolia. It extends even to Shangyi, Hebei Province. It is stable in lithological character, but it is gradually thinned from west to east owing to denudation.
GeoJSON
Fossils
In the lower lithological association, there are some elements of Conophyton cylindricum, C. garganicum and Tabuloconigera f., Stratifera f. The stromatolites in uppermost stratigraphic position are Colonnela, Baicalia, Scopulimorpha etc., and elow them occur some elements of Pseudogymnoso lenceae.
Age
Depositional setting
Additional Information
Chronologically, there may be a diachronous phenomenon.