Home Multi-Country Search About Admin Login
Cenozoic
Cretaceous
Jurassic
Triassic
Permian
Carboniferous
Devonian
Silurian
Ordovician
Cambrian
Neoproterozoic
Mesoproterozoic

Search by
Select Region(s) to search
Hold Ctrl (Windows/Linux) or Command (Mac) to select multiple
Dahuoluoshan Formation
Click to display on map of the Ancient World at:
Dahuoluoshan Fm base reconstruction

Dahuoluoshan Fm

Period: 
Neoproterozoic

Age Interval: 
Upper Qingbaikouan (middle Tonian); Qb （5, 6）


Province: 
Gansu, Inner Mongolia

Type Locality and Naming

Beishan. The Dahuoluoshan Fm was named by Wang Dawei et al. in 1968. The typical section is located in Dahuoluoshan in Mazongshan village, Subei Mongolian Autonomous County, Gansu Province. Upper formation of the Yuanzaoshan Gr.

Synonym: （大豁落山组）


Lithology and Thickness

The Dahuoluoshan Fm is dominantly composed of gray white cherty zebra dolomite, dolomitic-marble, dolomitic crystalline limestone, crystalline limestone and pelitic limestone intercalated with chert, which are dominated by the thick-bedded intercalated with the medium-to thin-bedded, bearing abundant stromatolites. Middle part is dominated by thin-bedded limestone intercalated with pelitic limestone generally bearing stylolite structures, bird's eye structure, desiccation cracks, tidal beddings etc. The thickness is from 1572- 3241 m. Its thickness and lithology are obviously varied, in Dahuoluoshan, it is more than 3241 m. Westward to Zelumu-Dahongshan area, it intercalated with sandy slate, and it is more than 1572 m thick at EjinQi (Inner Mongolia).


Lithology Pattern: 
Dolomitic limestone


Relationships and Distribution

Lower contact

The Dahuoluoshan Fm overlies conformably the underlying Yemajie Fm

Upper contact

Underlies unconformably the overlying Sinian Xichangjing Fm (tillite)

Regional extent

Beishan. Inner Mongolia and northernmost Gansu. With a widespread distribution, the Dahuoluoshan Formation is exposed west from Fangshankou in the boundary of Gansu and Xinjiang Weiwuerzhu Zizhiqu (Xinjiang Uygur Autonomous Region), eastward to Daquan, Zelumu, Dahongshan, Pingtoushan, Dahuoluoshan and Wutongjing, until to EjinaQi, Inner Mongolia.


GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[96.51,42.68],[98.16,42.5],[98.93,41.93],[100.23,41.34],[100.68,40.84],[101.01,40.18],[100.79,39.86],[99.93,40.09],[98.78,40.54],[97.16,41.04],[96.07,41.52],[94.52,42],[92.86,42.6],[92.16,43.18],[92.42,43.59],[93.14,43.71],[95.16,43.44],[96.51,42.68],[103.02,42],[104.41,41.75],[109.96,42.47],[111.57,43.44],[113.29,43.17],[113.39,42.57],[112.83,41.33],[110.12,40.81],[109.04,40.78],[107.73,40.59],[106.49,39.52],[105.92,39.39],[104.9,38.98],[104.61,39.14],[104.49,39.6],[104.19,39.93],[102.44,40.31],[101.84,41.4],[100.69,41.6],[99.62,42],[99.95,42.46],[100.98,42.53],[101.96,42.28],[103.02,42]]]]}}

Fossils

The Dahuoluoshan Fm has large stromatolite reefs, which are represented by an assemblage of Gymnosolen, Linella and Boxonia. The lower part is dominated by Gymnosolen ramsayi, G. scabridus, Tungussia inna, T. nodosa, the middle part yields Linella avis, L.ukka, L.strumosa, L. beishanensis, Jacutophyton f., Inzeria tjomusi, Kotuikania cf. toralosa etc., and the upper part yields Boxonia grumulosa, Dahuoluoshanella conica, and in addition, oncolite Osagia simplex, O. cylindrica etc.


Age 

Shown as late QIngbaikouan (middle Tonian)

Age Span: 

    Beginning stage: 
Tonian

    Fraction up in beginning stage: 
0.4

    Beginning date (Ma): 
888.00

    Ending stage: 
Tonian

    Fraction up in the ending stage: 
0.8

    Ending date (Ma):  
776.00

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.