Ohio Geology By Andrew Morton

The alternating shale and limestone in Ohio’s Ordovician crop out in the Cincinnati region, exposing a vast amount of well-preserved fossils. Ohio’s Ordovician rocks were the source of the first oil and gas field in the country.

During the Ordovician Ohio was covered by shallow seas. Ohio’s Ordovician rocks record the collision of the North American and European continents. Cincinnatian rocks are divided into three types: offshore, transitional, and shoreface.

Types of Fossils Trilobites Bryozoans Starfish Corals No remains of fish in Cincinnatian fossils