Columbus Limestone

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

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 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]

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.

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]

• List of types of limestone