Gull River Formation

The Gull River Formation is a geological formation of Middle Ordovician age (Caradoc Stage), which outcrops in Ontario, Canada.[1] Lithologically, the formation is dominated by light grey to brown limestones and greenish gray dolomites with thin shale and sandstone interlayers.[2][3]

Gull River Formation Stratigraphic range: Caradoc ~460.9–449 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Gull River Formation exposed along the shore of Lake St. John, Ramara
Type	Formation
Unit of	Simcoe Group Black River Group
Underlies	Bobcaygeon Formation Coboconk Formation
Overlies	Shadow Lake Formation
Lithology
Primary	Limestone, dolomite
Other	Shale, sandstone
Location
Region	Ontario, New York
Country	Canada, United States
Type section
Named for	Gull River
Named by	V. J. Okulitch
Year defined	1939

References

1. "Gull River formation". Natural Resources Canada. January 9, 2008. Retrieved January 4, 2015.
2. Armstrong, Derek K.; Dodge, J. E. P. (2007). Paleozoic Geology of Southern Ontario (PDF). Ontario Geological Survey. p. 4. ISBN 978-1-4249-4526-9.
3. Armstrong, D. K. (2000). Paleozoic Geology of the Northern Lake Simcoe Area, South-Central Ontario (PDF). Ontario Geological Survey. pp. 9–15. ISBN 978-0--7778--9451--4.

See also

• List of fossiliferous stratigraphic units in Ontario