Age of the Appalachians Part 1: Geology Ground Rules

Research & Collections

One of those things that “everybody knows” is that the Appalachians are the “oldest in the world.”  That conclusion is usually based on the amount that the Appalachians are eroded- young mountains, sharp topography, old mountains, rounded topography. But the age of the Appalachians is a simple question with no simple answer. A good guide can be downloaded from the United States Geological Survey if you click here.

To get at the answer, you need to know something about the way geologists do business. So this is part 1 of a two-part blog.

Geology is often oversimplified as the study of rocks, but if you look closer, it is actually the study of deep time and the sequence of events. You can build a picture of a sequence of events by crosscutting relationships: Younger events cut across older events.

Sediments stack up on top of each other, so…

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