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
Xiaogaolu Gr

Xiaogaolu Gr

Period: 
Neoproterozoic

Age Interval: 
Late Sinian (late Ediacaran), (31)


Province: 
Qinghai

Type Locality and Naming

Quanji block (NW Qinghai)

Synonym: upper Quanji Gr (when it had encompassed the entire Proterozoic succession)

[Figure: Location of the Quanji Block and Xiaogaolu Gr (from Wang et al., 2022)]


Lithology and Thickness

It consists of a Diamictite (Hongtiegou Fm) overlain by Limestone and sandstone (Zhoujieshan Fm )

[Figure: Measured sections of the Quanji Gr, Heitupo Fm, and Xiaogaolu Gr (from Wang et al., 2022)]


Lithology Pattern: 
Sandy limestone


Relationships and Distribution

Lower contact

This massive diamictite rests unconformably on the Hongzaoshan Fm (Hóngzàoshān Fm) of uppermost Quanji Gr (ca. 1.6 Ga, hence a major 1-billion-year hiatus), or on the black shales of the Heitupo Fm (ca. 1.3 Ga, hence a major 0.7 Myr hiatus).

Upper contact

Overlain disconformably by Cambrian carbonate and siliciclastic rocks of the Olongbuluke Gr and Ordovician carbonate rocks of the Duoquanshan Fm.

Regional extent

Quanji block (NW Qinghai) or Olongbuluke block of the northeastern Tibetan Plateau is a 350 km long, northwest– southeast oriented Precambrian cratonic continental fragment located south of the Qilian belt (see flgure) covered by late Paleoproterozoic to lower Paleozoic sedimentary rocks.


GeoJSON

null

Fossils

Iconic frondose rangeomorph Charnia of latest Ediacaran and the ribbon-shaped Shaanxilithes. a potential index fossil of the latest Ediacaran.


Age 

The Xiaogaolu Group is considered as a late Proterozoic succession according to the Ediacaran fossil Charnia and the ribbon-shaped fossils Shaanxilithes from the Zhoujieshan Fm. Wang et al. (2022) suggest that the underlying glacial diamictite of the Hongtiegou Fm might be a post-Gaskiers glacial episode; but for graphic purposes, it is assigned to Gaskiers here.

Age Span: 

    Beginning stage: 
Ediacaran

    Fraction up in beginning stage: 
0.55

    Beginning date (Ma): 
582.09

    Ending stage: 
Ediacaran

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
538.80

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

Extracted from Wang, C., Evans, D.A.D. et al., 2022. Proterozoic-Mesozoic development of the Quanji Block from northern Tibet and the cratonic assembly of Eastern Asia, American Journal of Science,. 322: 705-727 (and ESSO-Archive version that contains more lithostratigraphic information and images).