Ea Sup Fm
Type Locality and Naming
Holostratotype: along the Ea Sup and Ya Hleo streams, in the Buon Ea Sup area (x = 13°10’; y = 107°56’)- Bui Phu My, Vu Khuc, Phan Van Thuan 1992. The Continental red beds lie conformably upon terrigenous sediments containing Early Jurassic ammonites, occurring in the northern and southern margins of the Da Lat Depression, where they were found and described recently as Ea Sup Formation.
Synonym: Hệ tầng Ea Súp: Vũ Khúc, Bùi Phú Mỹ, Trần Tính (in Vũ Khúc 1993); Trần Tính et aỉ. 1998; Nguyễn Đức Thắng « al. 1999; Bùi Phú Mỹ 2000; Vù Khúc et ai. 2000,2001. - Điệp Bản Đôn (part.): Nguyễn Xuân Bao, Tạ Hoàng Tinh 1979; Tạ Hoàng Tinh và nnk. 1985; Tạ Hoàng Tinh (in Vũ Khúc, Bùi Phụ Mỹ et aỉ. 1990). - Hệ tầng Chiu Riu: Ma Công Cọ et ai. 1999.
Lithology and Thickness
The formation stratotype was established in the Ea Sup area, along the Ea Sup and Ya Hleo streams with 4 members. (1). Light grey to brownish-grey, medium- to thick-bedded, medium-grained sandstone, often with large cross-bedded structure, with some interbeds of chocolate-coloured, greenish-grey siltstone, 80 m thick. (2). Chocolate-coloured, medium-bedded siltstone interbedded with yellowish, fine-grained sandstone and chocolate-coloured, sometimes variegated claystone, 40 m thick; claystone contains the thin-shelled, small-sized lacustrine bivalves Tutuella rotunda, and T. sp. of Middle Jurassic age. (3). Greenish-grey to brownish, thin- to medium-bedded, often cross-bedded, fine-grained and medium-grained sandstone, with some interbeds of chocolate-coloured siltstone containing fine mica flakes, 60 m thick. (4). Chocolate-colourcd, medium-bedded siltstone rhythmically interbedded with thin- to medium-bedded, fine-grained sandstone containing fine mica flakes, 280 m thick. The sừeam extends into Cambodia; therefore the uppermost part of the section cannot be observed in Viet Nam. The total thickness of the formation in this section is 460 m.
Relationships and Distribution
Lower contact
Rests conformably on the Dray Linh Fm of Early Jurassic.
Upper contact
Unconformably underlies Late Jurassic volcanics of the Deo Bao Loc Fm.
Regional extent
The formation is present mostly in the Buon Ea Sup and SE Ban Don areas, but also in small exposures in the Buon Ho, Ca Lui River areas and, recently, was found in the south, at Loc Thanh, Loc Ninh District, where it was described as the Chiu Riu Fm.
GeoJSON
Fossils
Lacustrine bivalves Tutuella rotunda, and T. sp. of Middle Jurassic
Age
Depositional setting
Additional Information