Gull River Formation | |
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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 | ![]() ![]() ![]() |
Country | ![]() ![]() |
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. [1] Lithologically, the formation is dominated by light grey to brown limestones and greenish gray dolomites with thin shale and sandstone interlayers. [2] [3]
Chelicerates reported from the Gull River Formation | |||||
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Genus | Species | Presence | Material | Notes | Images |
Lunataspis | L. borealis | Upper Member, Kingston, Ontario. [4] | 3 specimens (1 adult & 2 juveniles or subadults). [4] | A horseshoe crab. |
Acritarchs reported from the Gull River Formation | |||||
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Genus | Species | Presence | Material | Notes | Images |
Dicommopalla | D. rissae | Southern Ontario. [5] | Also found in the Bobcaygeon Formation. |