| Cashaqua Shale | |
| Type: | Formation |
| Age: | Devonian |
| Region: | , |
| Unitof: | Sonyea Group |
| Underlies: | West Falls Group |
| Overlies: | (see description) |
The Cashaqua Shale is a geologic formation in New York. It preserves fossils dating back to the Devonian period.
The Cashaqua shale underlies the Rhinestreet Shale member of the West Falls Group, and overlies various other members of the Sonyea Group. In the western part of New York State, it overlies the Middlesex Shale, and moving eastward, it overlies the Pulteney shale and then the Rock Stream Formation in west-central New York.