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
Mahalagou Formation

Mahalagou Fm

Period: 
Paleogene

Age Interval: 
?middle Eocene to early Oligocene, (6c)


Province: 
Gansu, Qinghai

Type Locality and Naming

Lanzhou-Xining region. Named after Mahalagou in Huangzhong County, Qinghai Province. Qinghai Bureau of Geology and Mineral Resources, 1991, Regional Geology of Qinghai Province [Geological Memoirs of the Ministry of Geology and Mineral Resources of the People’s Republic of China, (1) Regional Geology, no.24], Beijing: Geological Publishing House, 209. First appeared in a 1977 manuscript by Huang Youyuan.

Synonym (or equivalent): Yehucheng Fm (in adjacent Gansu sub-basin). Former larger lacustrine setting was disrupted by late Cenozoic tectonics; hence different sub-basin names for the same strata.


Lithology and Thickness

Red calcareous silty mudstone with gray gypsiferous mudstone. Light brown, yellowish brown sandy mudstone with interbeds of gypsum rocks.


Lithology Pattern: 
Gypsiferous claystone


Relationships and Distribution

Lower contact

The equivalent Yehucheng Fm has a conformable contact with the underlying Eocene Xiliugou Fm.

Upper contact

It has a conformable contact with the overlying Xiejia Fm

Regional extent

Lanzhou-Xining region.


GeoJSON

null

Fossils


Age 

Oligocene; but indicated as extending down to mid-Ypresian by Y.Q. Wang et al. (2019, Paleogene chapter of China Integrated Stratigraphy and Timescale).

Age Span: 

    Beginning stage: 
Ypresian

    Fraction up in beginning stage: 
0.5

    Beginning date (Ma): 
52.04

    Ending stage: 
Rupelian

    Fraction up in the ending stage: 
0.5

    Ending date (Ma):  
30.60

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

Geological Formation Names of China (Springer Publ.)