Editing Geology of the Appalachians (section)

=== Overview ===
The [[Appalachian Mountains]] formed through a series of mountain-building events over the last 1.2 billion years:<ref>{{cite web|title=Geologic Events Affecting Eastern North America|publisher=Columbia University|url=https://www.columbia.edu/~vjd1/East_NAm_geo_events.htm}}</ref><ref>{{Cite book |last=Byerly |first=Don W. |title=The Last Billion Years: A Geologic History of Tennessee |publisher=University of Tennessee Press |year=2013 |isbn=978-1572339743}}</ref>

* The [[Grenville orogeny]] began 1250 million years ago (Ma) and lasted for 270 million years.
* The [[Taconic orogeny]] began 450 Ma and lasted for 10 million years.
* The [[Acadian orogeny]] began 375 Ma and lasted 50 million years.
* The [[Alleghanian orogeny]] began 325 Ma and lasted 65 million years.