| Tanos Formation | |
|---|---|
| Stratigraphic range: Oligocene, | |
 Tanos Formation outcrop near Espinaso Ridge, New Mexico, USA | |
| Type | Formation |
| Unit of | Santa Fe Group |
| Underlies | Blackshare Formation |
| Overlies | Espinaso Formation |
| Thickness | 279 m (915 ft) |
| Lithology | |
| Primary | Mudstone, sandstone |
| Other | conglomerate |
| Location | |
| Coordinates | 35°24′50″N 106°18′40″W / 35.414°N 106.311°W |
| Region | New Mexico |
| Country |  United States |
| Type section | |
| Named for | Arroyo de la Vega de los Tanos |
| Named by | Connell et al. |
| Year defined | 2002 |
  Tanos Formation (the United States)  Tanos Formation (New Mexico) | |
The Tanos Formation is a geologic formation in central New Mexico. It is estimated to be about 25 million years in age, corresponding to the Oligocene epoch.[1]