How were the Appalachian mountains formed?

The Appalachian Mountains (French: les Appalaches), often called the Appalachians, are a system of mountains in eastern North America. The Appalachians first formed roughly 480 million years ago during the Ordovician Period. read more

A look at rocks exposed in today's Appalachian mountains reveals elongate belts of folded and thrust faulted marine sedimentary rocks, volcanic rocks and slivers of ancient ocean floor. Strong evidence that these rocks were deformed during plate collision. read more

Appalachian Mountains - Geology: The Appalachians are among the oldest mountains on Earth, born of powerful upheavals within the terrestrial crust and sculpted by the ceaseless action of water upon the surface. The two types of rock that characterize the present Appalachian ranges tell much of the story of the mountains’ long existence. read more