| Mazantic Shale | |
| Type: | Formation |
| Age: | Miocene, |
| Period: | Miocene |
| Prilithology: | Shale |
| Country: | Mexico |
| Underlies: | Balumtum Sandstone |
| Overlies: | La Quinta Formation |
| Thickness: | 310 m |
The Mazantic Shale is a geologic formation in Chiapas, Mexico.[1] It was deposited during the Early Miocene (Aquitanian). The formation comprises dark gray shales that were deposited in a marine environment. It preserves fossils, such as the turtle Allaeochelys liliae. Amber has been recovered from it.[2]