Georgian Bay Formation

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.[2]

Georgian Bay Formation
Stratigraphic range: Upper Ordovician (upper Maysvillian-lower Richmondian)[1]
TypeFormation
Underlies
OverliesBlue Mountain Formation[2]
Location
Region Michigan,  Ontario
Country United States,  Canada

Description edit

The formation consists of massive shale interbedded with siltstone/sandstone and limestone, with sub-horizontal bedding planes and widely spaced jointing.[3]

Fossil content edit

Color key
Taxon Reclassified taxon Taxon falsely reported as present Dubious taxon or junior synonym Ichnotaxon Ootaxon Morphotaxon
Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.

Ichnotaxa edit

Ichnotaxa
Genus Species Presence Material Notes Images
Paleodictyon P. isp. A Southern Ontario.[1] 2 specimens, ROM 49424 and ROM 49624.[1]
?P. isp. B Southern Ontario.[1] 1 specimen: ROM 49625.[1]
Planolites P. constriannulatus Southern Ontario.[4]

Vertebrates edit

Conodonts
Genus Species Presence Material Notes Images
Amorphognathus A. ordovicicus Lower part of the formation.[2] Also found in the Blue Mountain Formation.
Aphelognathus A. grandis Uppermost lower and upper members.[2]
A. politus Lower part of the formation.[2] Also found in the Blue Mountain Formation.
A. pyramidlis Upper member.[2]
Belodina B. confluens Lower member at southern Georgian Bay.[2]
Coelocerondontus C. trigonius Lower part and Upper member of the formation.[2]
Decoriconus D. fragilis Upper member, Kagawong West Quarry.[2]
Drepanoistodus D. suberectus Lower part, uppermost lower and upper members of the formation.[2] Also found in the Blue Mountain Formation.
Gen. et. sp. indet. 1 Upper member.[2]
Gen. et. sp. indet. 2 Upper member, Kagawong West Quarry.[2]
Gen. et. sp. indet. 3 Upper member, Kagawong West Quarry.[2]
Icriodella I. prominens Upper member, Kagawong West Quarry.[2]
I. superba Lower part of the formation.[2]
Oulodus O. robustus Upper and lower members.[2]
O. ulrichi Upper member.[2]
O. undulatus Upper member.[2]
Ozarkodina O. aff. O. hassi Upper member, Kagawong West Quarry.[2]
Panderodus P. gracilis Lower part and upper member of the formation.[2]
P. aff. P. gracilis Uppermost lower and upper members.[2]
P. staufferi Lower part and upper member of the formation.[2]
Paroistodus P. mutatus Lower part of the formation.[2] Also found in the Blue Mountain Formation.
Periodon P. grandis Lower part of the formation.[2] Also found in the Blue Mountain Formation.
Phragmodus P. undatus Lower part and upper member of the formation.[2] Also found in the Blue Mountain Formation.
Plectodina P. inclinata Upper member at southern Georgian Bay.[2]
P. tenuis Lower part and upper member of the formation.[2]
Pseudobelodina P. inclinata Upper member, Manitoulin Island.[2]
P. cf. P. kirki Upper member, Manitoulin Island.[2]
P. microdentata Manitoulin Island.[2]
P. quadrata Upper member,Manitoulin Island.[2]
P. vulgaris vulgaris Upper member,Manitoulin Island.[2]
Pseudooneotodus P. beckmanni Upper member, Kagawong West Quarry.[2]
Rhipidognathus R. symmetricus Upper part of the formation.[2]
Staufferella S. falcata Lower member at southern Georgian Bay.[2]
Walliserodus W. curvatus Upper member, Kagawong West Quarry.[2]
Zanclodus Z. sp. Upper member.[2]

Invertebrates edit

Arthropods
Genus Species Presence Material Notes Images
Orcanopterus O. manitoulinensis Kangawong Submember, Manitoulin Island.[5] A eurypterid.
 
Brachiopods
Genus Species Presence Material Notes Images
Kinnella K. laurentiana Lower Kagawong Submember.[6] An orthide.
Other animals
Genus Species Presence Material Notes Images
Curviconophorus C. andersoni Scleritomous metazoan.[7]


See also edit

References edit

  1. ^ a b c d e Stanley, D. C.A.; Pickerill, R. K. (1993-07-01). "Shallow marine Paleodictyon from the Upper Ordovician Georgian Bay Formation of southern Ontario". Atlantic Geology. 29 (2). doi:10.4138/1994. ISSN 1718-7885.
  2. ^ a b c d e f g h i j k l m n o p q r s t u v w x y z aa ab ac ad ae af ag ah ai aj ak Zhang, Shunxin; Tarrant, Glen A.; Barnes, Christopher R. (November 2011). "Upper Ordovician conodont biostratigraphy and the age of the Collingwood Member, southern Ontario, Canada1Earth Science Sector (ESS) Contribution 20100302". Canadian Journal of Earth Sciences. 48 (11): 1497–1522. doi:10.1139/e11-047. ISSN 0008-4077.
  3. ^ Cao, Laifa; Peaker, S. M.; Ahmad, Shaheen; Sirati, A. (September 2014). "Engineering characteristic of Georgian Bay Formation in Toronto". GeoRegina. doi:10.13140/2.1.2400.5123.
  4. ^ Christopher, D.; Stanley, A.; Pickerill, Ron K. (January 1994). "Planolites constriannulatusisp. nov. from the Late Ordovician Georgian Bay Formation of southern Ontario, eastern Canada". Ichnos. 3 (2): 119–123. doi:10.1080/10420949409386379. ISSN 1042-0940.
  5. ^ STOTT, CHRISTOPHER A.; TETLIE, O. ERIK; BRADDY, SIMON J.; NOWLAN, GODFREY S.; GLASSER, PAUL M.; DEVEREUX, MATTHEW G. (November 2005). "A NEW EURYPTERID (CHELICERATA) FROM THE UPPER ORDOVICIAN OF MANITOULIN ISLAND, ONTARIO, CANADA". Journal of Paleontology. 79 (6): 1166–1174. doi:10.1666/0022-3360(2005)079[1166:anecft]2.0.co;2. ISSN 0022-3360.
  6. ^ A., Stott, Christopher (2007). The earliest known Kinnella, an orthide brachiopod from the Upper Ordovician of Manitoulin Island, Ontario, Canada. OCLC 999203691.{{cite book}}: CS1 maint: multiple names: authors list (link)
  7. ^ Rudkin, David M (1998). "A new scleritomous metazoan from the Late Ordovician Georgian Bay Formation, southern Ontario". Canadian Journal of Earth Sciences. 35 (7): 827–831. doi:10.1139/e98-032. ISSN 0008-4077.