The Columbus Limestone is of Middle Devonian age and was named for Columbus, Ohio where it has long been quarried. The Ohio Statehouse is constructed of this limestone. The Columbus Limestone crops out in a north-south line from Kelleys Island in Lake Erie to south of Columbus and many quarries are, or have been, actively removing this high-calcium limestone for use in production of cement, rip-rap, driveway gravel and road base, agricultural lime, and other uses. The unit was formed in a clear, shallow, tropical sea that covered the state. Fossils of marine animals are abundant in the Columbus Limestone.