Gezi Fm
Period:
Silurian
Age Interval:
Aeronian to Lower Telychian of Silurian (S1), (39, 40)
Province:
Gansu, Sichuan
Type Locality and Naming
It was proposed by Fu Lipu et al. in 1983. The type section is at Goujiaozi of Wuaba in Diebu County, Gansu Province. The reference section is at Baiyigou of Ruoergai County, Sichuan Province.
Synonym: (各子组)
Lithology and Thickness
It consists of dark grey, grayish black silty slate and phyllite intercalated with limestone lenses. The formation is over 600 m in thickness.
Lithology Pattern:
Pelagic marl
Relationships and Distribution
Lower contact
It rests conformably in between the underlying Anzigou Fm
Upper contact
It rests conformably in between the overlying Jiannigou Fm
Regional extent
The variation in lithology and thickness yet remain unclear because of rareness of the exposures.
GeoJSON
null
Fossils
It yields graptolites, such as Monograptus sedgwickii, Spirograptus turriculatus, Streptograptus sp., etc.
Age
Age Span:
Beginning stage:
Aeronian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
440.49
Ending stage:
Telychian
Fraction up in the ending stage:
0.2
Ending date (Ma):
437.46
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Wang Chuanshang and Wang Xiaofeng