Digging into the bedrock of Cincinnati

Cincinnati Magazine turned to a geoscientist at the University of Cincinnati to help tell the story of the Queen City's ancient past when it was part of an enormous shallow sea.

During the Ordovician period 450 million years ago, Cincinnati was a vast tropical sea. And more weirdly, Cincinnati was located in the southern hemisphere as many as 1,300 miles south of of the equator.

Evidence of this ancient world remains in virtually every creek bed in Cincinnati today through fossils of trilobites, horn corals and other marine creatures.

“You get beautiful snapshots of a sea bottom that was probably buried by a storm or, as I’ve argued, a tsunami-type deposit,“ UC College of Arts and Sciences Professor Carlton Brett told Cincinnati magazine. “Things were literally buried alive. So you get these spectacular layers of detail where you can see the trilobites reacting to the disturbances, layers where they’re caught rolling into balls.”

Brett said the bedrock of the city is equally fascinating. Tectonic forces deep underground created what's known as the Cincinnati Arch upon which the city rests.

Geologists identified this arch during a geological survey in 1839, according to the Cincinnati Museum Center. To the west is the Illinois Basin. The Michigan Basin lies to the north. And to the east are the Appalachian mountains and their attendant basin.

Featured image at top: A trilobite on display in UC's Durrell Geology Museum in the Department of Geosciences. Photo/Joseph Fuqua II/UC