Thuy Nguyen Gr
Period:
Devonian, Carboniferous
Age Interval:
Late Devonian-Early Carboniferous (5, 6)
Province:
East Bac Bo
Type Locality and Naming
Thuy Nguyen (Hai Phong City); named by Tong Duy Thanh (2000). Includes the Trang Kenh Fm (Late Devonian), and the coeval Con Voi Fm and Pho Han Fm (Tournaisian of Early Carboniferous).
Synonym:
Lithology and Thickness
Limestone to siliceous limestone. See component formations.
Lithology Pattern:
Limestone
Relationships and Distribution
Lower contact
Conformable (transitional) on the Van Huong Fm of Givetian age.
Upper contact
Pseudo-conformable under the Bac Son Fm.
Regional extent
Kinh Mon (Hai Duong Province), Thuy Nguyen (Hai Phong City) areas, and on some coastal islands of the East Bac Bo region.
GeoJSON
{"type":"Feature","geometry":{"type":"MultiPolygon","coordinates":[[[[106.9426,20.9496],[107.0675,21.1144],[107.3319,21.2882],[107.5419,21.3697],[107.7103,21.4675],[107.8968,21.4729],[108.0072,21.176],[107.9348,20.9207],[107.4278,20.6925],[107.149,20.6907],[107.0078,20.7903],[106.9426,20.9496]]]]}}
Fossils
See component formations.
Age
Late Givetian through Tournaisian.
Age Span:
Beginning stage:
Givetian
Fraction up in beginning stage:
0.8
Beginning date (Ma):
380.18
Ending stage:
Tournaisian
Fraction up in the ending stage:
1.0
Ending date (Ma):
346.73
Depositional setting
It is composed of the Van Canh (newly established) and Duong Dong Fms having conformable contacts with each other.
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).