| Chamita Formation | |
|---|---|
| Stratigraphic range: Neogene, | |
 Chamita Formation near the type section, Chamita, New Mexico | |
| Type | Geological formation |
| Unit of | Santa Fe Group |
| Underlies | Puye Formation |
| Overlies | Tesuque Formation |
| Thickness | 210 metres (690 feet) |
| Lithology | |
| Primary | Sandstone |
| Other | Tuff, siltstone, conglomerate |
| Location | |
| Coordinates | 36°04′42″N 106°05′11″W / 36.0783°N 106.0864°W |
| Region |  New Mexico |
| Country |  United States |
| Type section | |
| Named for | Chamita, New Mexico |
| Named by | Galusha and Blick |
| Year defined | 1971 |
  Chamita Formation (the United States)  Chamita Formation (New Mexico) | |
The Chamita Formation is a geologic formation in north-central New Mexico. It preserves unique fossils dating back to the Neogene period. The presence of volcanic ash beds in the formation, which can be radiometrically dated, gives the absolute age of the fossils, which is valuable for establishing the geologic time scale of the Neogene.