Cam Thuy Fm
Period:
Permian
Age Interval:
Late Permian; P3ct, (7, 11)
Province:
West Bac Bo
Type Locality and Naming
Lithology and Thickness
Lithology Pattern:
Lava
Relationships and Distribution
Lower contact
Unconformably overlies the limestone of the Bac Son Fm.
Upper contact
Conformably underlying the Yen Duyet Fm (upper P3)
Regional extent
The Cam Thuy Fm is characterized by mafic volcanogenic sedimentary lithology wide spreads in West Bac Bo. Its distribution is close to that of die overlying Yen Duyet Fm, and it is widespread in the southeast of the Song Ma Anticlinorium, on the territory of the Thanh Hoa, Ninh Binh, and Hoa Binh provinces; besides, there are small exposures in Lao Cai and Son La provinces.
GeoJSON
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Fossils
Pachyphloia, Textularia, Siaffella (?) and Geiniizina in the vicinities of Cam Thuy Townlet, and Pachyphloia, Geinitzina, Nodosaria,
Age
Late Permian. [Conformable below Late Changhsingian age Van Duyet Fm of upper Changhsingian. Strat column graphics suggests late Wuchiapingian-early Changhsingian?].
Age Span:
Beginning stage:
Wuchiapingian
Fraction up in beginning stage:
0.7
Beginning date (Ma):
255.83
Ending stage:
Changhsingian
Fraction up in the ending stage:
0.5
Ending date (Ma):
253.07
Depositional setting
Depositional pattern:
Additional Information
Compiler:
Tran Van Tri and Vu Khuc (Editors; Geology and Earth Resources of Viet Nam, General Dept. of Geology and Minerals of Viet Nam; completed in Dec., 2011), with additional details from Tong-Dzuy Thanh and Vu Khuc (Editors; Stratigraphic Units of Viet Nam, 2nd edition; 2011; English edited by A. Boucot).