| Sonyea Group | |
|---|---|
| Stratigraphic range: Frasnian | |
| Type | Group |
| Unit of | Frasnian |
| Sub-units | See text |
| Underlies | West Falls Group |
| Overlies | Genesee Group and Harrell Shale |
| Lithology | |
| Primary | Shale |
| Other | Siltstone |
| Location | |
| Region | Appalachian Basin of eastern North America[1] |
| Country | United States |
 Stratigraphic cross-section of the Sonyea Formation in New York State[2] | |
The Sonyea Group is a geologic group in the northern part of the Appalachian Basin. It preserves fossils dating back to the Devonian period.
In the western part,[1][3] it is divided into the Cashaqua Shale at the top, and the Middlesex Shale at the bottom. In the east, various shale formations are included between the Cashaqua and Middlesex members, including Rye Point Shale,[4] Rock Stream Formation ("Enfield Formation") Siltstone, Pulteney shale, Sawmill Creek Shale, Johns Creek Shale and Montour Shale.
- ^ a b "Sonyea Group". USGS. Retrieved 2015-09-17.
- ^ Colton, George W.; de Witt, Wallace Jr. (1958). "Stratigraphy of the Sonyea Formation of Late Devonian Age in Western and West-Central New York". United States Geological Survey. United States Department of the Interior. Retrieved 22 September 2015.
- ^ Rickard, L.V.; Isachsen, Y.W.; Fisher, D.W. (1970). "Geologic map of New York: Finger Lakes sheet". New York State Museum. Retrieved 2015-09-17.
- ^ "Sonyea Group (NYDs;5) on Sonyea Group (NYDs;5)".