Minh Hoa Fm

Period:

Triassic

Age Interval:

Anisian (T₂a mh) (29)

Province:
West Nam Bo, Vietnam Offshore south

Type Locality and Naming

Holostratotype - The unique section of the formation occurs on the northern side of Minh Hoa Island (also called Hon Nghe Island), Kien Giang Province, in the Gulf of Thailand (N = 10°02'; E = 104°34’). The formation bears the name of this island..

Synonym: - Hệ tầng Minh Hoà: Nguyễn Xu.n Bao et ai. 1991, 2000 (Anisi); Nguyễu Ngọc Hoa el ./.1995; Vũ Kh.c (in Vũ Kh.c eí ai. 2000 (Anisi). - Calcaire ?Permien: Fontaine H., 1968. - Hệ tầng Hòn Nghệ (part.): B.i Ph. Mỹ, Vũ Kh.c 1980 (T2 ); Vũ Kh.c, B.i Ph. Mỹ et aí. 1990 (T2 ). - Dá vôi Hòn Nghệ: Vũ Kh.c (irt Tống Duy Thanh el ai. 1995 - Anisi).

Lithology and Thickness

Limestone: The section includes only light-grey, thick-bedded to massive limestone, approximately 200 m thick.

Lithology Pattern:

Limestone

Relationships and Distribution

Lower contact

The lower boundary has not been observed on the island. Regionally, the next older formation is the Permian Dat Do Fm.

Upper contact

Tectonic contact with the Jurassic Ta Pa Fm lying on the northern side of the island through a NW-SE trending fault; there the fault left a thin zone of tectonic breccias.

Regional extent

Gulf of Thailand

GeoJSON

null

Fossils

Foraminifera and hexacorals (not studied). Foraminifera were determined by Doan Nhat Truong, including Endotelỉa controversa, E. sp. (ex gr. E, bithynica), E. badouxi, Diplotremina astrofimbriata, D. sp., Duostroma sp., Pilaminella falsofriedu, and Malayspira fontainei of Anisian-Ladinian age.

Age

Based on existing materials and the former determination of Nguyen Van Liem the Minh Hoa Fm has been dated as Anisian, possibly Late Anisian.

Age Span:

Beginning stage:

Anisian

Fraction up in beginning stage:

0.5

Beginning date (Ma):

244.08

Ending stage:

Anisian

Fraction up in the ending stage:

1.0

Ending date (Ma):

241.46

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, 2^nd edition; 2011; English edited by A. Boucot).