The Columbus Limestone is a mapped bedrock unit consisting primarily of fossiliferous limestone. It occurs in Ohio, Pennsylvania, and Virginia in the United States, and in Ontario, Canada.
Description
Depositional environment The depositional environment was most likely shallow marine.
Stratigraphy The Columbus conformably overlies the Lucas Dolomite in northeastern Ohio, and unconformably overlies other dolomite elsewhere. It unconformably underlies the Ohio Shale in northwestern Ohio and the Delaware Limestone in eastern Ohio.Ohio Division of Geological Survey, 1990 (rev. 2000, 2004), Generalized Column of Bedrock Units in Ohio; Ohio Department of Natural Resources, Division of Geological Survey, 1p. http://www.dnr.state.oh.us/Portals/10/pdf/stratcol.pdf
Its members include: Bellepoint, Marblehead, Tioga Ash Bed, Venice, Delhi, Klondike, and East Liberty.
Notable Exposures The type section is located in Columbus, Ohio. The glacial grooves on Kelleys Island are cut into the Columbus Limestone. It is also quarried there. An exposure in Ontario is located at Ingersoll, Ontario.Ehlers, G. M., and Stumm, E. C., 1951, Middle Devonian Columbus limestone near Ingersoll, Ontario, Canada, AAPG Bulletin; v. 35; no. 8; p. 1879-1888. August.
Fossils The Columbus Limestone contains brachiopods, trilobites, bryozoans, mollusks, corals, stromatoporoids and echinoderms (including crinoids).
Due to their mid-continent depositional environment, the fossils are almost free of deformation caused by tectonic activity common in the Appalachian Mountains.
Corals +TabulataTaxonSpeciesNotesSyringoporaS. tabulataFavositesF. hemispherica minutaEmmonsiaE. polymorphaThamnoptychiaT. alternansPleurodictyumIndeterminateCoenitesC. dublinensis +RugosaTaxonSpeciesNotesPrismatophyllumP. rugosumHexagonariaH. annaEridophyllumE. serialeSynaptophyllumS. simcoenseAmplexusA. yandelliZaphrenthisZ. perovalisHeterophrentisH. nitidaCystiphylloidesC. americanumOdontophyllumO. convergensSiphonophrentisS. giganteaHadrophyllumH. dorbignyi Wells, J.W., 1944, Middle Devonian bone beds of Ohio: Geological Society of America Bulletin, v. 55, no. 3, p. 273-302.
Cephalopods TaxonSpeciesNotesWernerocerasW. staufferiGoniatiteSweet, W. C., and Miller, A. K., 1956, Goniatites from the Middle Devonian Columbus Limestone of Ohio, Journal of Paleontology, vol. 30, No. 4, p 811-817. July.TornocerasT. eberleiGoldringiaG. cyclops
Other Invertebrates TaxonSpeciesNotesSpiriferS. macrothyrisBrachiopodBrevispiriferB. gregariusLaevidentalhumL. martineiGastropodNucleocrinusN. verneulliCrinoid
Fish TaxonSpeciesNotesDrepanaspidaeIndeterminateFrom the East Liberty Member ("East Liberty bone bed")CephalaspidaeGyracanthus?PlectrodusAcanthodiiMachaeracanthus M. major"Acanthoides"A. dublinensisCoccosteusC. spatulatusPtyctodusRhynchodusPalaeomylusCladoselachidaePhoebodusOnychodusO. sigmoides
Age Relative age dating of the Columbus Limestone places it in the Early to Middle Devonian period.
Economic Uses The Columbus has been mined for aggregate. Its Calcium carbonate content is 90% or higher.GeoFacts No. 25, Ohio Department of Natural Resources, Division of Geological Survey
References
See also List of types of limestone