Songzong Gr
Period:
Devonian
Age Interval:
D2-3 (25), Middle to Late Devonian
Province:
Xizang (Tibet)
Type Locality and Naming
The type section location is unknown, and the reference section is at Ranwuya-Laigu, Basuo County of Tibet. It was named by Li Pu in 1955.
Lithology and Thickness
Limestone. The group, 940 m thick, is composed of gray to dark-gray thin-bedded limestone, medium-to thick-bedded dolomitic limestone and clayey limestone, intercalated with siliceous limestone in the lower part.
Lithology Pattern:
Limestone
Relationships and Distribution
Lower contact
Unknown – Thrust fault contact onto Jurassic. However, regionally, the next older exposed formation is the Chunjieqiao Fm (used in Lexicon chart for regional column)
Upper contact
The group is conformably overlain by the Lower Carboniferous Qingduo Gr.
Regional extent
GeoJSON
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Age
Middle to Late Devonian (uncertain base due to fault)
Age Span:
S
Beginning stage:
Eifelian
Fraction up in beginning stage:
0.0
Beginning date (Ma):
394.30
Ending stage:
Famennian
Fraction up in the ending stage:
1.0
Ending date (Ma):
359.30
Depositional setting
Depositional pattern:
Additional Information
Compiler:
(Xian Shiyuan)