Song Ba Fm
Type Locality and Naming
Tay Nguyen Highland area. The type section is established along the Song Ba River Valley, in the section extending from Le Bac Bridge to Phu Tuc Townlct, Gia Lai Province (N = 13° 12’; E = 108°42’).
Synonym: Điệp Sông Ba: Trinh Dánh (in Vũ Khúc và link.) 1984; Trịnh Dánh 1985,1993 (Miocen muộn), Hệ tầng Sông Ba: Trần Tính et al. 1998; Trịnh Dánh (in Vũ khúc et al.) 2000. Hệ tầng Sông Ba (part.): Trịnh Dánh (in Phan Cự Tiổn et al.) 1989; (in Vũ Khúc, Bùi Phú Mỹ et al.) 1990.
Lithology and Thickness
Typical intermontaine basin succession (350-450 m) is: (1) Conglomerate with interbeds of gritty sandstone and feldspar-rich sandstone; 200 m. (2) Rhythmic intercalation of gritty sandstone with conglomerate, and some coal seams in places; 200-300 m. (3) Greenish-gray silty sandstone to claystone, usually containing calcaro-cherty concretions, and in some places, bentonite lenses; 40-60 m thick.
Relationships and Distribution
Lower contact
Unconformably rests upon the Lower-Middle Jurassic Ban Don Gr (Binh Son Fm), upon rhyolite of the Middle Triassic Mang Yang Fm or upon granite of Jurassic-Cretaceous age (associated with Deo Bac Loc Fm).
Upper contact
Unconformably overlain by the Kon Tum Fm
Regional extent
The Song Ba Fm occurs in the valley of the Song Ba River, in the Plei Ku (Gia Lai Province) and Kon Turn Towns, Dak To Townlct (Kon Turn Province) and Buon Ma Thuot City (Dac Lak Province) areas. Along the valley of the Song Ba River, in the section extending from the Le Bac bridge to the Phu Tuc Townlet.
GeoJSON
Fossils
Diospyros brachysepala, Sapindus linearyfolius, Phoebe pseudolanceolata, Phragmites oeningensis, Dipterocarpus sp., Castanopsis sp., Laurus sp., etc..
Laurus vetusla, Ocotea foetens, Ficus beauveriei, Phragmites oeningetisis, Persea sp., Quercus sp., Dipterocarpus sp..
Laurus sỉmilis, Ocotea foe tens, Ulmus carpinoides, Zyziphiis miojujuba, Dipterocarpus sp., Ficus beauveriei, Carya phaseolites, Phragmites oeningensis, Hoped sp. and a palynological assemblage with 10- 16.5% ferns including Lygodium, Polypodium, Lycopodium, Gleichenia; 79-80% angiosperm pollen with species of Sapotaceae, Apocynaceae, Dipterocarpaceae, Juglandaceae (with Platycarya, Carya), Fagaceae (with Quercus, Castanea, Castanopsis) etc.; 2-4.5% gymnosperm pollen of Dacrydiutn, Cycas, Ginkgo, Pinus, etc..
Age
Depositional setting
It is interpreted as intermontaine basins.
Additional Information