| Columbus Limestone | |
| Type: | Sedimentary |
| Prilithology: | Limestone |
| Otherlithology: | Sandstone |
| Namedfor: | Columbus, Ohio |
| Namedby: | Mathur, 1859 |
| Region: | Cincinnati Arch of North America |
| Unitof: | Onondaga Group |
| Subunits: | Bellepoint, Marblehead, Tioga Ash Bed, Venice, Delhi, Klondike, East Liberty |
| Overlies: | Lucas Formation |
| Underlies: | Bass Islands Formation, Delaware Formation, and Ohio Shale |
| Thickness: | 0 to 105 feet[1] |
| Extent: | Ohio, Pennsylvania, Virginia, Ontario |
| Age: | Devonian |
| Period: | Devonian |
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.
The depositional environment was most likely shallow marine.
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.[2]
Its members include: Bellepoint, Marblehead, Tioga Ash Bed, Venice, Delhi, Klondike, and East Liberty.
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.
| Syringopora | S. tabulata | [4] |
| Favosites | F. hemispherica minuta | |
| Emmonsia | E. polymorpha | |
| Thamnoptychia | T. alternans | |
| Pleurodictyum | Indeterminate | |
| Coenites | C. dublinensis |
| Prismatophyllum | P. rugosum | ||
| Hexagonaria | H. anna | ||
| Eridophyllum | E. seriale | ||
| Synaptophyllum | S. simcoense | ||
| Amplexus | A. yandelli | ||
| Zaphrenthis | Z. perovalis | ||
| Heterophrentis | H. nitida | ||
| Cystiphylloides | C. americanum | ||
| Odontophyllum | O. convergens | ||
| Siphonophrentis | S. gigantea | ||
| Hadrophyllum | H. dorbignyi | [5] [6] |
| Taxon | Species | Notes | |
|---|---|---|---|
| Werneroceras | W. staufferi | Goniatite[7] | |
| Tornoceras | T. eberlei | ||
| Goldringia | G. cyclops | [8] |
| Taxon | Species | Notes | |
|---|---|---|---|
| Spirifer | S. macrothyris | Brachiopod | |
| Brevispirifer | B. gregarius | ||
| Laevidentalhum | L. martinei | Gastropod | |
| Nucleocrinus | N. verneulli | Crinoid |
| Taxon | Species | Notes |
|---|---|---|
| Drepanaspidae | Indeterminate | From the East Liberty Member ("East Liberty bone bed") |
| Cephalaspidae | ||
| Gyracanthus? | ||
| Plectrodus | ||
| Acanthodii | ||
| Machaeracanthus | M. major | |
| "Acanthoides" | A. dublinensis | |
| Coccosteus | C. spatulatus | |
| Ptyctodus | ||
| Rhynchodus | ||
| Palaeomylus | ||
| Cladoselachidae | ||
| Phoebodus | ||
| Onychodus | O. sigmoides |
Relative age dating of the Columbus Limestone places it in the Early to Middle Devonian period.
The Columbus has been mined for aggregate. Its Calcium carbonate content is 90% or higher.[9]