Agua de la Piedra Formation
The Agua de la Piedra Formation (FAP, Spanish names include Estratos de Agua de la Piedra and Complejo Volcano-sedimentario del Terciario inferior) is a Late Oligocene (Deseadan in the SALMA classification) geologic formation of the Malargüe Group that crops out in the southernmost Precordillera and northernmost Neuquén Basin in southern Mendoza Province, Argentina.
| Agua de la Piedra Formation | |
|---|---|
| Stratigraphic range: Late Oligocene (Deseadan) ~ | |
| Type | Geological formation |
| Unit of | Malargüe Group |
| Sub-units | "Rodados Lustrosos" level |
| Underlies | alluvium |
| Overlies | Pircala-Coihueco Formation |
| Thickness | 37 metres (121 ft) (tuffs) |
| Lithology | |
| Primary | Tuff |
| Other | Paleosols |
| Location | |
| Coordinates | 36.6°S 69.7°W |
| Approximate paleocoordinates | 37.8°S 62.9°W |
| Region | southern Mendoza Province |
| Country | Argentina |
| Extent | southernmost Precordillera northernmost Neuquén Basin |
| Type section | |
| Named by | Gorroño et al. |
| Location | Quebrada Fiera, Malargüe |
| Year defined | 1979 |
| Coordinates | 36°33′13.3″S 69°42′3.5″W |
| Region | Mendoza Province |
| Country | Argentina |
| Thickness at type section | 37 metres (121 ft) (tuffs) |
Agua de la Piedra Formation (Argentina) | |
The strictly terrestrial tuffs and paleosols of the formation, geologically belonging to Patagonia, have provided a wealth of mammal fossils of various groups at Quebrada Fiera, including Mendozahippus fierensis, Pyrotherium, Coniopternium and Fieratherium. Terror birds reminiscent of the terror bird Andrewsornis and indeterminate remains of the phorusrhacid family have found in conjunction with the mammals.