| Indio Formation | |
| Type: | Formation |
| Age: | Ypresian (Wasatchian-Bridgerian) ~ |
| Period: | Ypresian |
| Prilithology: | Sandstone, shale |
| Otherlithology: | Conglomerate, claystone |
| Region: | Nuevo León and Tamaulipas |
| Unitof: | Wilcox Group |
The Indio Formation is a geologic formation of the Wilcox Group in Mexico. The sandstones, shales, conglomerates and claystones preserve fossils dating back to the Ypresian age (Wasatchian to Bridgerian in the NALMA classification) of the Eocene epoch of the Paleogene period.[1]