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

Keshan Fm

Period: 
Cretaceous

Age Interval: 
Late Cretaceous, K2k, (36a)


Province: 
Zhejiang

Type Locality and Naming

The Zhejiang Petroleum Geological Team erected the Zhejiang Rhyolite in its summary report of petroleum geological work (unpublished) in 1959. The section for the designation is in Keshan of Xinchang of the Laixian County, Zhejiang.


Lithology and Thickness

The Keshan Formation is represented by a set of light flesh rhyolite porphyry. It is 100 m thick generally. But it is in excess 100 m in Keshan of Xinchang, 51.9 m in Maanshan of Shaoxing, more than 81 m in Shuangxikou of Jinyun, and up to 238.7 m in Bijiashan of Gaoping of Suichang.


Lithology Pattern: 
Lava


Relationships and Distribution

Lower contact

Its base marked by rhyolite porphyry is distinguished from the shale with small calcareous nodules of the underlying Fangyan Fm (uppermost Yongkang Gr). It shows an eruptive unconformable contact with the underlying strata.

Upper contact

Its top is not exposed completely.

Regional extent

The formation occurs in Bijiashan of Gaoping of Suichang, Qiaoshan and Wuyishan of Xinchang and Maanshan of Shaoxing. It is represented by intruded -overflowed acidic lava. In Shuangxikou east of Jinyun acid tuff occurs on conglomerate, and in Geshanjian of Dongyang, the formation is represented by gray purple rhyolitic crystal and vitric ignimbrite.


GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[120.53,29.79],[120.79,29.83],[120.89,29.74],[120.8,29.6],[120.71,29.32],[120.82,28.36],[120.49,28.41],[120.18,28.31],[119.84,28.16],[119.56,28.13],[119.4,28.31],[119.4,28.57],[119.5,28.68],[119.82,29],[120,29.18],[120.17,29.54],[120.53,29.79]]]]}}

Fossils

None listed


Age 


Age Span: 

    Beginning stage: 
Cenomanian

    Fraction up in beginning stage: 
0.5

    Beginning date (Ma): 
97.20

    Ending stage: 
Cenomanian

    Fraction up in the ending stage: 
0.8

    Ending date (Ma):  
95.22

Depositional setting


Depositional pattern:  


Additional Information


Compiler:  

Wan Xiaoqiao