OHIO — While there is no ancient ocean beneath Ohio today, the state’s bedrock preserves evidence of a long-lost ocean that helped shape eastern North America hundreds of millions of years ago.
The ancient Iapetus Ocean formed between about 600 million and 540 million years ago as the supercontinent Rodinia broke apart. At the time, what is now Ohio sat along the stable edge of the ancient North American continent, known as Laurentia.
According to the Ohio Department of Natural Resources, the opening of the Iapetus Ocean created tectonic forces that stretched the Earth’s crust, leading to the formation of large fault-bounded basins. One of those features, known as the Rome Trough, developed south and east of present-day Ohio through parts of Kentucky, West Virginia and Pennsylvania, where thick layers of sediment accumulated. The Iapetus Ocean itself lay farther east of Ohio rather than directly beneath the state…