The Georgian Bay Formation is a geologic formation in Michigan and Ontario. It preserves fossils dating back to the Ordovician period. The type locality of the formation is on East Meaford Creek (previously called Workman Creek), south shore of Nottawasaga Bay, Georgian Bay.
Description The formation consists of massive shale interbedded with siltstone/sandstone and limestone, with sub-horizontal bedding planes and widely spaced jointing.
Fossil content
Ichnotaxa Ichnotaxa Genus Species Presence Material Notes ImagesPaleodictyonP. isp. ASouthern Ontario.2 specimens, ROM 49424 and ROM 49624.?P. isp. BSouthern Ontario.1 specimen: ROM 49625.PlanolitesP. constriannulatusSouthern Ontario.
Vertebrates Conodonts Genus Species Presence Material Notes ImagesAmorphognathusA. ordovicicusLower part of the formation.Also found in the Blue Mountain Formation.AphelognathusA. grandisUppermost lower and upper members.A. politusLower part of the formation.Also found in the Blue Mountain Formation.A. pyramidlisUpper member.BelodinaB. confluensLower member at southern Georgian Bay.CoelocerondontusC. trigoniusLower part and Upper member of the formation.DecoriconusD. fragilisUpper member, Kagawong West Quarry.DrepanoistodusD. suberectusLower part, uppermost lower and upper members of the formation.Also found in the Blue Mountain Formation.Gen. et. sp. indet. 1Upper member.Gen. et. sp. indet. 2Upper member, Kagawong West Quarry.Gen. et. sp. indet. 3Upper member, Kagawong West Quarry.IcriodellaI. prominensUpper member, Kagawong West Quarry.I. superbaLower part of the formation.OulodusO. robustusUpper and lower members.O. ulrichiUpper member.O. undulatusUpper member.OzarkodinaO. aff. O. hassiUpper member, Kagawong West Quarry.PanderodusP. gracilisLower part and upper member of the formation.P. aff. P. gracilisUppermost lower and upper members.P. staufferiLower part and upper member of the formation.ParoistodusP. mutatusLower part of the formation.Also found in the Blue Mountain Formation.PeriodonP. grandisLower part of the formation.Also found in the Blue Mountain Formation.PhragmodusP. undatusLower part and upper member of the formation.Also found in the Blue Mountain Formation.PlectodinaP. inclinataUpper member at southern Georgian Bay.P. tenuisLower part and upper member of the formation.PseudobelodinaP. inclinataUpper member, Manitoulin Island.P. cf. P. kirkiUpper member, Manitoulin Island.P. microdentataManitoulin Island.P. quadrataUpper member,Manitoulin Island.P. vulgaris vulgarisUpper member,Manitoulin Island.PseudooneotodusP. beckmanniUpper member, Kagawong West Quarry.RhipidognathusR. symmetricusUpper part of the formation.StaufferellaS. falcataLower member at southern Georgian Bay.WalliserodusW. curvatusUpper member, Kagawong West Quarry.ZanclodusZ. sp.Upper member.
Invertebrates Arthropods Genus Species Presence Material Notes Images OrcanopterusO. manitoulinensis Kangawong Submember, Manitoulin Island. A eurypterid.
Brachiopods Genus Species Presence Material Notes Images KinnellaK. laurentiana Lower Kagawong Submember. An orthide. Other animals Genus Species Presence Material Notes Images CurviconophorusC. andersoni Scleritomous metazoan.
See also
List of fossiliferous stratigraphic units in Michigan
References