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Yemajie Formation
Click to display on map of the Ancient World at:
Yemajie Fm base reconstruction

Yemajie Fm

Period: 
Neoproterozoic

Age Interval: 
early Qingbaikous (early Tonian), Qb (5, 6)


Province: 
Gansu, Inner Mongolia

Type Locality and Naming

Beishan. The Yemajie Fm was named by Fan Guolin (1994). The type section is located in the northeast slope of Pingtuo Hills and the southwest of Yemajie (meteorological station), Niujuanzi area, Subei County, Gansu Province. Lower formation of the Yuanzaoshan Gr.

Synonym: （野马街组）


Lithology and Thickness

The Yemajie Fm consists of a series of gray, purple thin-bedded siltstone, phyllite, phyllitic silty shale, chert and fine-grained sandstone and sandstone. Going eastwards, the formation increases its thickness, and consists of gray green, gray red silty mudstone with quartz sandstone and limestone with clear sedimentary rhythmic layering. The formation is over 355 m thick southwest of Yemajie, and 3000 m thick in Wangxunshan.


Lithology Pattern: 
Siltstone


Relationships and Distribution

Lower contact

The formation is disconformable with the underlying Pingtaoshan Fm of the Jixian System (lower Mesoproterozoic) (Shule Movement ).

Upper contact

The top is conformably overlain by the Dahuoluoshan Gr

Regional extent

Beishan. Inner Mongolia and northernmost Gansu. The formation has a restricted extent. It occurs from the Yemajie meteorological station in the northeast slope of Pingtoushan, Subei County, going eastwards to Wangxushan area of Ejin Qi, Inner Mongolia.


GeoJSON

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Fossils

Stromatolites Linella f. etc. are found in interbeds of limestone.


Age 

Shown as early Qingbaikous (early Tonian) on stratigraphic column

Age Span: 

    Beginning stage: 
Tonian

    Fraction up in beginning stage: 
0.0

    Beginning date (Ma): 
1,000.00

    Ending stage: 
Tonian

    Fraction up in the ending stage: 
0.4

    Ending date (Ma):  
888.00

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

Extracts from The Neoproterozoic Erathem (chapter in Stratigraphic Lexicon of China, draft of 2022) by Gao Linzhi, Ding Xiaozhong, Zhang Chuanheng, Zhang Heng.