Horn Coral (Little Current, Manitoulin Island, Ontario)

[CabinTom]

Found along the shore of the North Channel at Little Current on Manitoulin Island.

 

Any chance this can be ID'd more specifically?

 

 

I

[Thomas.Dodson]

Possibly. Step #1 would be to determine the age and formation of where this came from. You can use the location it was found and the bedrock type to match it to a formation and age from this geologic map of the Little Current area. http://www.geologyontario.mndm.gov.on.ca/mndmfiles/pub/data/imaging/P2670/P2670.pdf

 

Step #2 involves searching for literature that describes the fauna of that formation or age in the area. If you're lucky someone has already done the work for that stuff in the area. If this fails you will need to expand your search to literature of that formation outside your area, similar aged formations, or fauna described from that age.

 

Step #3 is matching the species from literature. This can be easy or hard depending on the coral fauna present but forum members will be happy to help with any difficulties in determining this.

 

 

Maybe @Kane is familiar with this area and could eliminate a step or 2.

[Kane]

If it is from the Little Current outcrops, I can be reasonably certain it is Ordovician in age. As for more than "horn coral," I won't be much help given my focus on other fauna. There isn't terribly much literature on Ordovician fauna up there. I can recommend a few papers:

 

Johnson, M.E., and R. Jia-Yu. Middle to Late Ordovician rocky bottoms and rocky shores from the Manitoulin Island area, Ontario. Journal of Earth Sciences 26, 642-653 (1989).

 

Foerste, A. F. The Ordovician section int he Manitoulin area of Lake Huron. The Ohio Naturalist XIII: 2, 37-48 (1912).

 

Copper, P. and D. J, Grawbarger. Paleoecological succession leading to late Ordovician biostrome on Manitoulin Island, Ontario. Canadian Journal of Earth Sciences 15, 1987-2005 (1978)

 

You may have some luck searching GEOSCAN: https://geoscan.nrcan.gc.ca/starweb/geoscan/servlet.starweb?path=geoscan/geoscan_e.web

 

And possibly some more contextual sources:

 

Brookfield, M. E., & Brett, C. E. (1988). Paleoenvironments of the Mid-Ordovician (Upper Caradocian) Trenton limestones of southern Ontario, Canada: Storm sedimentation on a shoal-basin shelf model. Sedimentary Geology, 57, 75-105.

Brunton, F. R., Turner, E., & Armstrong, D. (2009). A Guide to the Paleozoic Geology and Fossils of Manitoulin Island and northern Bruce Peninsula, Ontario, Canada. Canada Paleontology Conference (pp. 1-42). Sudbury: Ontario Geological Survey & Laurentian University.

 

Byerley, M., & Coniglio, M. (1989). Stratigraphy and sedimentology of the Upper Ordovician Georgian Bay Formation, Manitoulin Island and Bruce Peninsula. In Geosciences Research Grant Program, Summary of Research 1988-1989 (pp. 227-237). Ontario Geological Survey, Miscellaneous Paper 156.

 

Copper, P. (1978). Paleoenvironments and paleocommunities in the Ordovician-Silurian sequence of Manitoulin Island. Michigan basin Geological Society, Special Papers, No. 3, 47-61.

 

Liberty, B. A. (1968). Ordovician and Silurian stratigraphy of Manitoulin Island, Ontario. The Geology of Manitoulin Island , pp. 14-37.

Liberty, B. A. (1978). Ordovician nomenclature of Manitoulin Island. In Geology of the Manitoulin area. (J. T. Sanford, & R. Mosher, Eds.) Michigan Basin Geological Society, Special Paper 3, 43-45.

 

Sanford, J. T. (1978). The stratigraphy of the Manitoulin Island area. In Geology of the Manitoulin area. (J. T. Sanford, & R. E. Mosher, Eds.) Michigan Basin Geological Society, Special Paper 3, 31-41.

 

 

[CabinTom]

Thanks to both of you! This gives me some good direction and some interesting reading to do.

 

From looking at the map @Thomas.Dodson linked, the fossils I've been posting have been found on "Spider Island" (no longer an island), which is within the Lindsay Formation (Middle-Upper Ordovician).

 

 

Edited August 6, 2021 by CabinTom

[Kane]

6 minutes ago, CabinTom said:

From looking at the map @Thomas.Dodson linked, the fossils I've been posting have been found on "Spider Island" (no longer an island), which is within the Lindsay Formation (Middle-Upper Ordovician).

If you go south toward the new OPP station off the 540, there were some shale dumps from the new houses from the overlying Whitby/Collingwood, but those are now gone. A hard black shale under the immediate surface there with small, pyritized nautiloids and graptolites (but little else). Keep an eye out for new construction there if you want to add those to your collection.  

[FossilDAWG]

Two genera and species are frequent in the Ordovician of that area.  Lambeophyllum profundum is common in the lower formations (e.g. Gull River) but it does occur in formations above that.  Streptelasma corniculum occurs in the Bobcaygeon and Verulum, and is abundant in the Lindsey.  Your specimen looks most like a Lambeophyllum to me.

 

Don

[CabinTom]

23 hours ago, FossilDAWG said:

Two genera and species are frequent in the Ordovician of that area.  Lambeophyllum profundum is common in the lower formations (e.g. Gull River) but it does occur in formations above that.  Streptelasma corniculum occurs in the Bobcaygeon and Verulum, and is abundant in the Lindsey.  Your specimen looks most like a Lambeophyllum to me.

 

Don

 

Thank you!