| Caleta Chonos Formation | |
| Type: | Geological formation |
| Period: | Oligocene |
| Age: | Oligocene |
| Prilithology: | Conglomerate, sandstone |
| Otherlithology: | Coal, tuff breccia |
| Namedfor: | Caleta Chonos |
| Region: | Los Lagos Region |
| Coordinates: | -41.8°N -74°W |
| Underlies: | Ancud Volcanic Complex |
| Overlies: | Bahía Mansa Metamorphic Complex |
| Extent: | Lacuy Peninsula |
Caleta Chonos Formation (Spanish; Castilian: Formación Caleta Chonos) is a geological formation of Oligocene age located around Chacao Channel in southern Chile. The formation overlies Bahía Mansa Metamorphic Complex and is overlain by the Ancud Volcanic Complex. It crops out in northwestern Chiloé Island in the isthmus of Lacuy Peninsula.[1]