Sinuiju Formation
| Sinuiju Formation | |
|---|---|
| Stratigraphic range: Barremian-Aptian | |
| Type | Geological formation |
| Sub-units | 8 members |
| Overlies | Precambrian basement |
| Thickness | >500 metres (1,600 ft) |
| Lithology | |
| Primary | Sandstone, siltstone, mudstone |
| Other | Andesite |
| Location | |
| Coordinates | 40°06′N 124°24′E / 40.1°N 124.4°E |
| Approximate paleocoordinates | 43°48′N 125°48′E / 43.8°N 125.8°E |
| Country | North Korea |
| Type section | |
| Named for | Sinuiju city |
The Sinuiju Formation(신의주층) is a geologic formation in North Korea. Formerly of uncertain age, it is now thought to be Early Cretaceous. A variety of fossils are known from the formation, including those of anurognathid pterosaurs (possibly Jeholopterus) and birds such as the specimen of a very large enantiornithine with a 5 cm (2.0 in) long tibia and a 3.5 cm (1.4 in) long pygostyle. Frogs have also been found in the formation. Numerous compression fossils of insects have also been found.