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

Longyin Fm


Period: 
Permian

Age Interval: 
P1 (77), late Cisuralian Epoch (late Early Permian)


Province: 
Guizhou

Type Locality and Naming

The type section is located in the area of the Longyin Village 28 km to the east of the Pu’an County Town, Guizhou Province. It was named by the Guizhou Regional Geological Reconnaissance Party in 1973.


Lithology and Thickness

Clastics and Limestone. Interbedded yellow-brown siltstone, medium- and thick-bedded quartz-sandstone, micrite and marl. It is divisible into two parts as follows: Lower part is composed of brown, grey-brown and black clayey and sandy shales, intercalated with a small amount of quartz-sandstone and clayey limestone. Upper part is composed of yellow-brown quartz-sandstone, siltstone, claystone and carbonaceous shale. The basal part of the formation is composed of dark-grey and black thin-bedded siltstone, intercalated with micrite. Thickness is 250-300 m.


Lithology Pattern: 
Siltstone


Relationships and Distribution

Lower contact

Conformable contact with the dark-grey and grey medium- and thick-bedded micrites on the top of the underlying Shazitang Fm

Upper contact

Conformable contact with the dark-grey thick-bedded micrite and bioclastic limestone at the base of the overlying Baomoshan Fm

Regional extent

Distributed in the areas of the Panxian, Liuzhi, Pu’an and Qinglong Counties, with the limestone tending to increase in amount southerly to change physically to the Maping Fm.


GeoJSON

{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[104.93,25.75],[104.9,25.76],[104.85,25.77],[104.74,25.77],[104.68,25.78],[104.65,25.78],[104.6,25.78],[104.53,25.78],[104.5,25.8],[104.51,25.86],[104.55,25.87],[104.62,25.89],[104.68,25.9],[104.76,25.91],[104.92,25.91],[104.97,25.91],[105.06,25.9],[105.15,25.88],[105.2,25.88],[105.25,25.88],[105.3,25.88],[105.32,25.87],[105.33,25.82],[105.29,25.76],[105.25,25.74],[105.2,25.73],[105.14,25.72],[105.07,25.72],[105.01,25.73],[104.98,25.73],[104.96,25.74],[104.93,25.75]]]]}}

Fossils

In the Longyin area it yields Fusulinida fauna represented by Sphaeroschwagerina glomerosa, Pseudofusulina moelleri, as well as Ammonoid fauna represented by Popanoceras.


Age 

Late stage of the Early Permian Epoch

Age Span: 

    Beginning stage: 
Asselian

    Fraction up in beginning stage: 
0.5

    Beginning date (Ma): 
296.21

    Ending stage: 
Artinskian

    Fraction up in the ending stage: 
0.35

    Ending date (Ma):  
287.99

Depositional setting

It is interpreted as a shallow-sea facies deposit.


Depositional pattern:  


Additional Information


Compiler:  

Fei Shuying, Zhu Zili

GeoJSON estimate by Can Cai and Xinyi Zhang (Chengdu Univ. Tech. students)