Columbus Limestone
Geologic formation in the United States and Canada
From Wikipedia, the free encyclopedia
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.
| Columbus Limestone | |
|---|---|
| Stratigraphic range: Devonian | |
Etched section of hand sample of Columbus Limestone from Kelleys Island | |
| Type | Sedimentary |
| Unit of | Onondaga Group |
| Sub-units | Bellepoint, Marblehead, Tioga Ash Bed, Venice, Delhi, Klondike, East Liberty |
| Underlies | Bass Islands Formation, Delaware Formation, and Ohio Shale |
| Overlies | Lucas Formation |
| Thickness | 0 to 105 feet[1] |
| Lithology | |
| Primary | Limestone |
| Other | Sandstone |
| Location | |
| Region | Cincinnati Arch of North America |
| Extent | Ohio, Pennsylvania, Virginia, Ontario |
| Type section | |
| Named for | Columbus, Ohio |
| Named by | Mathur, 1859 |
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.[2]
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.[3]
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
| Taxon | Species | Notes |
|---|---|---|
| Syringopora | S. tabulata | [4] |
| Favosites | F. hemispherica minuta | |
| Emmonsia | E. polymorpha | |
| Thamnoptychia | T. alternans | |
| Pleurodictyum | Indeterminate | |
| Coenites | C. dublinensis |
| Taxon | Species | Notes |
|---|---|---|
| Prismatophyllum | P. rugosum | [4] |
| 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] |
Cephalopods
| Taxon | Species | Notes |
|---|---|---|
| Werneroceras | W. staufferi | Goniatite[7] |
| Tornoceras | T. eberlei | |
| Goldringia | G. cyclops | [5][8] |
Other Invertebrates
| Taxon | Species | Notes |
|---|---|---|
| Spirifer | S. macrothyris | Brachiopod[5] |
| Brevispirifer | B. gregarius | |
| Laevidentalhum | L. martinei | Gastropod[5] |
| Nucleocrinus | N. verneulli | Crinoid[5] |
Fish
| Taxon | Species | Notes |
|---|---|---|
| Drepanaspidae | Indeterminate | From the East Liberty Member ("East Liberty bone bed")[6] |
| Cephalaspidae | ||
| Gyracanthus? | ||
| Plectrodus | ||
| Acanthodii | ||
| Machaeracanthus | M. major | |
| "Acanthoides" | A. dublinensis | |
| Coccosteus | C. spatulatus | |
| Ptyctodus | ||
| Rhynchodus | ||
| Palaeomylus | ||
| Cladoselachidae | ||
| Phoebodus | ||
| Onychodus | O. 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.[9]