Thong - Mang Cau Fm

Period:

Neogene

Age Interval:

Middle Miocene; N₁², (31)

Province:
Vietnam Offshore south

Type Locality and Naming

Nam Con Son Basin. The type section is located established in borehole Dua-IX, at a depth of 2170 - 2852 m (N = 7°36’; E = 109°5’).

Synonym: Hệ tầng Thông - Măng cầu: Đồ Bạt 2000. Hệ tầng Thông, Hệ tầng Mãng cầu: Lồ Văn Cự 1982. Hệ tầng Thông - hệ tầng Mãng cầu: ĐÕ Bạt 1985, 1993. Hệ tằng yũng Tàu: Ngô Thường San 1982.

Lithology and Thickness

Its lower part sandstone containing glauconite and carbonate cement interbedded with claystonc and marl; grading upwards into interbedded carbonate-terrigenous sediments and limestone forming thick members of white-grey sediments. The total thickness of the formation in this borehole is 682 m.

Lithology Pattern:

Sandy limestone

Relationships and Distribution

Lower contact

Conformably upon the Dua Fm

Upper contact

Unconformably under the Nam Con Son Fm.

Regional extent

Nam Con Son Basin.

[Figure: Upper Jurassic - Tertiary Formation Correlation Chart (images courtesy of Prof. Ta Hoa Phuong, Vietnam Natl. Univ. Hanoi)]

GeoJSON

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Fossils

Fossils arc relatively abundant, Middle Miocene, belonging to the Florschuetzia meridionalis Zone; Florschuetzia trilobata Subzone; N9-N13, TÍ2-TÍ3 zones; andNN7-NN9 zones.

Age

Middle Miocene.

Age Span:

Beginning stage:

Langhian

Fraction up in beginning stage:

0.0

Beginning date (Ma):

15.99

Ending stage:

Serravallian

Fraction up in the ending stage:

1.0

Ending date (Ma):

11.63

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).