Gull River Formation
| Gull River Formation | |
|---|---|
| Stratigraphic range: Caradoc ~ | |
Gull River Formation exposed along the shore of Lake St. John, Ramara | |
| Type | Formation |
| Unit of | |
| Underlies |
|
| Overlies | Shadow Lake Formation |
| Lithology | |
| Primary | Limestone, dolomite |
| Other | Shale, sandstone |
| Location | |
| Region | Ontario New York Pennsylvania |
| Country | Canada United States |
| Type section | |
| Named for | Gull River |
| Named by | V. J. Okulitch |
| Year defined | 1939 |
The Gull River Formation is a geological formation of Middle Ordovician age (Caradoc Stage), which outcrops in Ontario, Canada. Lithologically, the formation is dominated by light grey to brown limestones and greenish gray dolomites with thin shale and sandstone interlayers.