| Phra Wihan Formation | |
|---|---|
| Stratigraphic range: Berriasian-Valanginian ~ | |
| Type | Geological formation |
| Unit of | Khorat Group |
| Underlies | Sao Khua Formation |
| Overlies | Phu Kradung Formation |
| Thickness | 150 m (490 ft) |
| Lithology | |
| Primary | Sandstone |
| Other | Siltstone, mudstone, conglomerate |
| Location | |
| Coordinates | 16°06′N 103°54′E / 16.1°N 103.9°E |
| Approximate paleocoordinates | 14°18′N 111°24′E / 14.3°N 111.4°E |
| Region | Northeast Thailand (Khorat Basin) |
| Country |  Thailand |
| Extent | Khorat Plateau |
| Type section | |
| Named for | Khao Phra Wihan, an 11th-century Khmer Temple (Khao Phra Wihan National Park) |
| Named by | Ward & Bunnag |
| Year defined | 1964 |
  Phra Wihan Formation (Thailand) | |
The Early Cretaceous Phra Wihan Formation is the second lowest member of the Mesozoic Khorat Group which outcrops in Northeast Thailand.
Comprises fine- to coarse-grained sheet and channelled sandstone beds and rarer variegated siltstone and mudstone. Intermittent conglomerate beds.
Deposited in a fluvial environment dominated by high-energy, shallow braided rivers with subordinate lower energy meandering river systems and associated flood plains.
The Phra Wihan Formation is considered to be Berriasian-Valanginian in age based on palynological analysis.[1][2][3]
Sauropod (fossil) tracks have been recorded from this formation.[4]
- ^ Suteetorn and Jarnyahran (1986). "Geological Map of Thailand." Sheet NE 48-14 1:250,000.
- ^ Racey and Goodall (2009). "Late Palaeozoic and Mesozoic Ecosystems in SE Asia". Geological Society. London. Special Publication 315 Pp 69-84.
- ^ Tucker, Ryan T.; Hyland, Ethan G.; Gates, Terry A.; King, M. Ryan; Roberts, Eric M.; Foley, Elliot K.; Berndt, David; Hanta, Rattanaphorn; Khansubha, Sasa-on; Aswasereelert, Wasinee; Zanno, Lindsay E. (September 2022). "Age, depositional history, and paleoclimatic setting of Early Cretaceous dinosaur assemblages from the Sao Khua Formation (Khorat Group), Thailand". Palaeogeography, Palaeoclimatology, Palaeoecology. 601: 111107. Bibcode:2022PPP...60111107T. doi:10.1016/j.palaeo.2022.111107. ISSN 0031-0182.
- ^ Weishampel, et al. (2004). "Dinosaur distribution." Pp. 517-607.