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

Zhamokti Fm

Period: 
Neoproterozoic

Age Interval: 
early Sinian (early Ediacaran), Z (8)


Province: 
Xinjiang

Type Locality and Naming

Kuruktag region. The Zhamokti Fm was named by Zhu Chengshun, Ye Yongzheng et al. (1957-1958), which was published by Gao Zhenjia (1981). The type section is located in Zhamokti spring of central Kuruktag, Xinjiang Weiwuerzhu Zizhiqu (Xinjiang Uygur Autonomous Region). A main reference section is located in near Dongda Mt. and Yardang Mt., Kesitanbulak, Xinjiang Weiwuerzhu Zizhiqu (Xinjiang Uygur Autonomous Region). Middle formation of the Kuruktag Gr (6 of 9).

Synonym: （扎莫克提租）


Lithology and Thickness

The Zhamokti Fm consists of a series of rhythmic sediments (turbidites or flysch) of gray, gray-green fining-upward beds of coarse-grained sandstone (often with lithic sandstone in the bottom), medium-grained sandstone, fine-grained sandstone, siltstone and muddy shale with incomplete Bouma sequences and graded bedding. The basal surfaces of beds have undertow marks including flute casts, groove marks and load marks. Horizontal and deformed laminations (disturbed beddings) are well developed. The Zhamokti Formation is 1230 m thick in the eastern Kuruktag. It decreases to 560- 920 m thick in the central and western part.

[Figure: Stratigraphic Column of the Kuruktag Gr]


Lithology Pattern: 
Clayey sandstone


Relationships and Distribution

Lower contact

The base of the formation is disconformable or unconformable with the underlying Teruiaiken Tillite (diamictite), and a bed of dolomite is often found at the top of the underlying rock (some geologists consider that the dolomite is carbonate rock cap formed at the top of tillite). Because of later erosion, the dolomite is absent in some regions. The formation could overlap different underlying formations, which shows unconformable and a weathering crust.

Upper contact

The top of the Zhamokti Fm is conformable with the overlying Yukengou Fm

Regional extent

Kuruktag region. The Zhamokti Formation is widely distributed in Kuruktag area, west from Moqinwula Mountains north of Korla, eastward to Xishankou, Moqinkuduk, and Luoqin jutubulak to the northeast and east of Yuli County and also to Yulegunbulak, south of Shanshan County.


GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[90.26,42.53],[90.81,42.13],[90.93,41.81],[90.8,41.5],[90.14,40.49],[89.51,40.05],[88.08,40.18],[86.52,40.26],[83.99,40.94],[83.52,41.45],[83.96,41.97],[85.88,42.24],[88.25,42.37],[90.26,42.53]]]]}}

Fossils

Abundant microplants have been found in this formation, such as Trachysphaeridium rude, T. cultum, T. incrassatum, Pseudozonosphaera asperella etc.


Age 

early Sinian (early Ediacaran),

Age Span: 

    Beginning stage: 
Ediacaran

    Fraction up in beginning stage: 
0.0

    Beginning date (Ma): 
635.00

    Ending stage: 
Ediacaran

    Fraction up in the ending stage: 
0.2

    Ending date (Ma):  
615.76

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.