Quang Ngai Fm
Type Locality and Naming
South Song Hong Basin. The type section is located borehole GK.l 19-CH drilled in the margin of the Quang Ngai Graben, at a depth of 790 to 1454 m (N = 15°17’15”; E= 109°3r40” ).
Synonym: Hệ tầng Quàng Ngãi. Lê Đình Thám 1992,1994,1998; SladcnC., Hoàng Ngọc Đang 1997; Phan Trung Điền 2000. Miocene Marl: BP 1991. Upper Miocene: Lamcrs E. 1992; Đồ Bạt 1993. Bac Bo Croup: Morris J. 1993.
Lithology and Thickness
Claystone with thin interbeds of siltstone, sandstone and some limestone, bearing carbonaceous materials, pyrite and glauconite. The claystone is light to dark grey, of medium consolidation, locally firm, massive. The siltstone is grey, dark grey, brown-grey, thick-bcddcd to massive, with ccment of clay and carbonate. Sandstone is white-grey, brownish-grey, with the grains often fíne, medium rounded, medium to well sorted, with the grains mainly of quartz and the cement of clay and carbonate. Limestone from interbeds is light to yellowish-grey, firm, massive, with a thickness of 0.5 -2 m (hole GK. 120-CS) bearing silt, clay and many marine fossils. The thickness of the formation in this borehole readies 664 m. The Quang Ngai Fm is developed regularly in the whole area of the depression with thickness changing from 500 to 800 m.
Relationships and Distribution
Lower contact
Unconformably upon the Tri Ton Fm.
Upper contact
Unconformably overlain by the Bien Dong Fm.
Regional extent
South Song Hong Basin.
GeoJSON
Fossils
Florschuetzia meridionalis, FI. levipoli, Ilex, Rhizophora, Dipterocarpidites, Dacrydium, Chenopodium, Liquidambar, Graminae, Loranihns, Stenochlaena laurifolia, Acrostichum, Pteris, Carya, Alnipollenites belonging to the Liquidambar - Florschuetzia meridioncitis - Ilex Assemblage of Late Miocene
Age
Depositional setting
It is interpreted as a coastal plain, shallow-sca, Continental shelf and dccp-marinc environments.
Additional Information