| Chucal Formation | |
| Type: | Geological formation |
| Period: | Miocene |
| Region: | Arica y Parinacota Region |
| Country: | Chile |
| Overlies: | Lupica Formation |
Chucal Formation (es|Formación Chucal) is a volcano-sedimentary geological formation in the Andes of Arica y Parinacota Region in northernmost Chile. Sediments of the formation deposited sometime during the Miocene epoch (23 to 5 million years ago) and represent fluvial and lacustrine environments.[1] It overlies Lupica Formation.[1]