Sai Bon Fm
Period:
Triassic
Age Interval:
Upper Triassic (3)
Province:
Sibumasu: Lower Peninsula
Type Locality and Naming
Nakhon Sri Thammarat province. It’s an informally named the Sai Bon Formation by Teerarungsikul et al. (1999).
Synonym: หมวดหินไสบอน
[Figure 1: Generalized distribution of different Triassic sedimentary environments and some of the more important lithostratigraphic units, and their relations to the terranes. (The geology of Thailand, 2011) page 146]
Lithology and Thickness
Red sandstone interbedded with argillaceous limestone, dolomitic limestone lenses, abundant bivalves, corals, gastropods, and ammonites. Thickness: 110 m.
Lithology Pattern:
Sandy limestone
Relationships and Distribution
Lower contact
Chaiburi Fm (conformable)
Upper contact
Khlong Min Fm (unconformable)
Regional extent
Lower Peninsula, Nakhon Sri Thammarat province
GeoJSON
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Fossils
In the same region, near Kantang, a black limestone was described by Ridd (1978) which has since been found to contain two new sphinctozoan sponge species, Platythalamiella minima n.sp. and Amblysiphonella parva n.sp. (Senowbari-Daryan & Ridd 2008). Based on the associated microflora, their age is considered to be Late Triassic and they are possibly the only recorded calcisponges from the Triassic of Thailand. The sponge-bearing Kantang limestone is a unit within a thicker interval of marine or perhaps lagoonal, calcareous sandstones and mudstones which match the brief description by Teerarungsigul et al. (1999) of the Sai Bon formation.
Age
Late Triassic (tentative) (Geology of Thailand, 2011)
Age Span:
Beginning stage:
Norian
Fraction up in beginning stage:
0.5
Beginning date (Ma):
219.01
Ending stage:
Rhaetian
Fraction up in the ending stage:
1.0
Ending date (Ma):
201.36
Depositional setting
Shallow marine deposits
Depositional pattern:
Additional Information
Compiler:
Wen Du - modified from- Chonglakmani, C.P., 2011, Chapter 6 Triassic in Ridd, M.F., Barber, A.J., and Grow, M.J., editors, The Geology of Thailand, Geol. Soc. of London.；Lexicon of Stratigraphic Names of Thailand of 2013.