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
Xisha Formation

Xisha Fm


Period: 
Neogene

Age Interval: 
Miocene, N, (37)


Province: 
South China Sea

Type Locality and Naming

South China Sea – Xisha islands. The type section is located at Xiyong Well No.1, Xisha Islands ("Paracel Islands"). It was named and surveyed by Wang C. et al. in 1976, published in 1979.

NOTE: There is not a standardized regional lithostratigraphy for the Xisha islands; nor for the nomenclature in the reference wells.

Synonym: Sanya Fm and Meishan Fm?


Lithology and Thickness

It is characterized by the grayish white calcareous algae- dolomite in Lower part; dolomitic limestone with bioclast in Bottom part; grayish white bioclastic limestone. Foraminifera, sporopollen, coral and algae fossils are yielded. The thickness is 401 m.


Lithology Pattern: 
Dolomitic limestone


Relationships and Distribution

Lower contact

It is unconformable in contact to underlying bedrock.

Upper contact

It is conformable in contact to overlying Xuande Fm.

Regional extent

The formation is distributed in area around Xisha Islands ("Paracel Islands").


GeoJSON

null

Fossils

Nephrolepidina morgana, Quinqueloculina spp., Triloculina sp., Pyrgo sp., Peneroplis pertusus, Amphicoryna sp., Ficus- Rhizophoraceae.


Age 

Lower dolomite = Early Miocene if equivalent to dolomitic Sanya Fm. Upper dolomitic limestone = Middle Miocene if equivalent to Meishan Fm.

Age Span: 

    Beginning stage: 
Aquitanian

    Fraction up in beginning stage: 
0.0

    Beginning date (Ma): 
23.04

    Ending stage: 
Serravallian

    Fraction up in the ending stage: 
1.0

    Ending date (Ma):  
11.63

Depositional setting

It is interpreted as an atoll environment.


Depositional pattern:  


Additional Information


Compiler:  

Tao Deng, Sukuan Hou, J.Z. Qigao, Q. Li, Q.Q. Shi, B.Y. Sun, S.Q. Wang, F.X. Wu