| Oxaya Formation | |
| Period: | Miocene |
| Age: | Late Oligocene–Early Miocene |
| Prilithology: | Ignimbrite |
| Namedfor: | Oxaya |
| Region: | Arica y Parinacota Region |
| Country: | Chile |
| Overlies: | Azapa Formation, Lupica Formation? |
| Thickness: | ca. 1000m (3,000feet) |
Oxaya Formation (es|Formación Oxaya) is a geological formation in northern Chile made up of ignimbrite sheets. The formation formed about 25 to 19 million years ago in the Late Oligocene and Early Miocene.[1] Oxaya Formation is deformed by the Oxaya anticline.[2]