Limestone Quarry - Virtual Tour Of Illinois History (sitios de interés)
Descripción del sitio
| What is now the city of Chicago lies in a broad plain which, hundreds of millions of years ago, was a great interior basin covered by warm, shallow seas. These seas divided North America, from the Arctic Ocean to the Gulf of Mexico. Evidence of these seas are found in the fossils of coral, such as those unearthed in Illinois quarries Reference |