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
Xinduqiao Formation

Xinduqiao Fm

Period: 
Triassic

Age Interval: 
Early-middle Late Triassic, (TJ74)


Province: 
Sichuan

Type Locality and Naming

The named section is located in Xinduqiao Town, Kangding County, Sichuan Province. And it was named by the Sichuan Province Regional Stratigraphic Table Compilation Group in 1978.

Synonym:


Lithology and Thickness

The Xinduqiao Fm is mainly composed of clastic rocks. Lower part consists of dark gray and black carbonaceous slate, silty slate intermingled with gray metamorphic quartz fine sandstone and siltstone; in the middle and upper part, there can be sand-argillaceous limestone lens with thickness of 400-700 m. Upper section is interbedded with grey and dark grey metamorphic feldspar quartz sandstone, siltstone and silty slate and slate. The thickness of this formation is about 800 to 1000 m.


Lithology Pattern: 
Sandy claystone


Relationships and Distribution

Lower contact

The black slate of the Xinduqiao Fm is in conformable contact to the underlying Zhuwo Fm

Upper contact

The pyrite bearing sandstone at the bottom of the overlying Yajiang Fm

Regional extent

This formation distributes in Kangding, Li County, Songpan, Ruoergai area of Sichuan. It is coeval with upward succession of Waduo Fm and Lianghekou Fm in Yneary ajiang and Yahui counties.


GeoJSON

null

Fossils

Bivalves in the lower section: Halobia ganziensis, H. pluriradiata, H. yunnanensis, H. convexa, etc.; In addition to the fossils found in the lower section, there are also Halobia superba, H. telleri, H. salinarum, H. eximia, etc.


Age 

In 1974, the survey team of the first area of Sichuan Geological Bureau classified the age of Xinduqiao Fm into the Carnian – Norian Period of the late Triassic. Sichuan district transfer team, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences (1982) and Rao Rongbiao et al. (1987) limited the age of this formation to the Carnian period. The Sichuan Bureau of Geology and Mineral Resources (1991) determined the age of this formation as the early and middle Norian of the late Triassic. Yang Zunyi et al. (2000) believe that the era of this formation should be classified into the late Carnian to the early and middle Norian of the Late Triassic. In 1977, the aviation area survey team of Sichuan Geological Bureau named the strata with roughly the same lithology, horizon and distribution as the Xinduqiao Fm as "Xianjire Formation".

Age Span: 

    Beginning stage: 
Carnian

    Fraction up in beginning stage: 
0.65

    Beginning date (Ma): 
230.70

    Ending stage: 
Norian

    Fraction up in the ending stage: 
0.5

    Ending date (Ma):  
216.52

Depositional setting

It is interpreted as the marine sediments.


Depositional pattern:  


Additional Information


Compiler:  

Zhang Shunxin, Zhang Shiyan and Tong Jinnan.