Río Seco de la Quebrada Formation
| Río Seco de la Quebrada Formation | |
|---|---|
| Stratigraphic range: Anisian-Carnian? | |
| Type | Geological formation |
| Unit of | Puesto Viejo Group |
| Overlies | Quebrada de los Fósiles Formation |
| Lithology | |
| Primary | Conglomerate |
| Other | Sandstone, shale, andesite |
| Location | |
| Coordinates | 34°54′S 68°36′W / 34.9°S 68.6°W |
| Approximate paleocoordinates | 51°30′S 34°06′W / 51.5°S 34.1°W |
| Region | Mendoza Province |
| Country | Argentina |
| Extent | San Rafael Block |
The Río Seco de la Quebrada Formation is a Triassic geological formation in Mendoza Province, Argentina. Fossils of cynodonts such as Cynognathus, Diademodon, and Pascualgnathus have been found in this formation, along with dicynodonts such as Vinceria and Acratophorus. Based on biostratigraphy, the Río Seco de la Quebrada Formation is considered to have formed during the Anisian stage, as it shares fauna with the upper subzones of the Cynognathus Assemblage Zone in South Africa. However, radiometric dating controversially argues that it was deposited during the early Carnian stage, 10 million years younger than expected otherwise.