Thunder Bay Limestone
Stratigraphic range:
TypeGeological formation
Unit ofTraverse Group[1]
Sub-unitsPartidge Point Member, Potter Farm Member, and Norway Point Member
UnderliesKettle Point Formation and Squaw Bay Limestone
OverliesPotter Farm Formation[1]
Location
Region Michigan
Country United States

The Thunder Bay Limestone is a geologic formation in Michigan. It preserves fossils dating back to the Devonian period.

Stratigraphy of the Devonian deposits of the northern part of the Lower Peninsula of Michigan, showing the Thunder Bay Limestone[1]

Fossil content

Vertebrates

Conodonts

Conodonts reported from the Thunder Bay Limestone
GenusSpeciesPresence MaterialNotesImages
Icriodus I. cymbiformis [2] Also found in the Detroit River, Traverse, Antrim, Ferron Point, Genshaw, Alpena and Norway Point formations.
I. expansus [2] Also found in the Detroit River, Traverse, Antrim, Lucas, Anderdon, Dundee, Bell, Ferron Point, Genshaw, Alpena, Potter Farm and Norway Point formations.
I. latericrescens latericrescens [2] Also found in the Traverse, Bell, Ferron Point, Genshaw, Newton Creek, Alpena, Four Mile Dam,,Norway Point and Potter Farm formations.
Polygnathus P. varcus [2] Also found in the Traverse, Antrim, Alpena, Four Mile Dam and Norway Point formations.

Placoderms

Placoderms reported from the Thunder Bay Limestone
GenusSpeciesPresence MaterialNotesImages
Ptyctodus P. sp. "Northeast shore of Partridge Point, 6.4 kilometers south of Alpena".[1] A tooth plate (UMMP 3023).[1] A ptyctodontid.

Invertebrates

Brachiopods

Brachiopods reported from the Thunder Bay Limestone
GenusSpeciesPresence MaterialNotesImages
Pentamerella P. proteus [3]
Spinulicosta S. mutocosta [3] Also found in the Bell, Rockport Quarry, Ferron Point, Four Mile Dam, Beebe School and Potter Farm formations.

Cnidarians

Cnidarians reported from the Thunder Bay Limestone
GenusSpeciesPresence MaterialNotesImages
Syringopora S. ehlersi Bluffs on northeast shore of Partridge Point, 4 miles south of Alpena, Alpena County.[4] A tabulate coral.

Echinoderms

Echinoderms reported from Thunder Bay Limestone
GenusSpeciesPresence MaterialNotesImages
Corocrinus C. pettyesi Bluffs on northeast shore of Partridge Point, 4 miles south of Alpena, Alpena County.[5] A crinoid.
Gennaeocrinus G. romingeri Bluffs on northeast shore of Partridge Point, 4 miles south of Alpena, Alpena County.[5] A crinoid.

Trilobites

Trilobites reported from the Thunder Bay Limestone
GenusSpeciesPresence MaterialNotesImages
Dechenella D. (Basidechenella) reimanni Alpena County, Michigan.[6]
D. (Basidechenella) sp. C Alpena County, Michigan.[6] A single specimen.[6]
Dipleura D. dekayi Partridge Point on Thunder Bay, about 4 miles south of Alpena.[6] Also found in the Norway Point Formation.
Greenops G. alpenensis Alpena County, Michigan.[6]
Phacops P. iowensis Alpena County, Michigan.[6] Also found in the Potter Farm and Petoskey formations.
Proetus P. (Crassiproetus) alpenensis [6] Also found in the Potter Farm Formation.

See also

References

  1. 1 2 3 4 5 6 Stack, Jack; Sallan, Lauren (2018-09-20). "An examination of the Devonian fishes of Michigan". PeerJ. 6 (2). doi:10.7717/peerj.5636. PMC 6151260.
  2. 1 2 3 4 Orr, R. William (1971). "Conodonts from Middle Devonian Strata from the Michigan Basin". {{cite journal}}: Cite journal requires |journal= (help)
  3. 1 2 Imbrie, John (1959). "Brachiopods of the Traverse group (Devonian) of Michigan. Part 1, Dalmanellacea, Pentameracea, Strophomenacea, Orthotetacea, Chonetacea, and Productacea. Bulletin of the AMNH ; v. 116, article 4". {{cite journal}}: Cite journal requires |journal= (help)
  4. ↑ Watkins, J. Lloyd (1959). "Middle Devonian Auloporid Corals from the Traverse Group of Michigan". Journal of Paleontology. 33 (5): 793–808. ISSN 0022-3360.
  5. 1 2 Kesling, Robert V. (1964). "Two New Crinoids of the Family Periechocrinitidae from the Middle Devonian Thunder Bay Limestone of Michigan". Contributions from the Museum of Paleontology, University of Michigan. XIX (11): 143–155.
  6. 1 2 3 4 5 6 7 Stumm, Erwin (1953). "Trilobites of the Devonian Traverse Group of Michigan" (PDF). University of Michigan Press - Museum of Paleontology.


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