News from Brown: https://news.brown.edu/articles/2016/11/appalachians
Some 300 million years ago the future "North America" bumped into the continent of Gondwana (today's Africa and South America). Gondwana slid in atop what would become South Carolina and parts of Florida, Georgia, and Tennessee, much like the process going on at the Himalayas today. The result: our southern Appalachians. Our Appalachians are indeed old. The story of the process is from scientists at Brown University.