Wanderlust World Wanderlust World The Appalachian Mountains (including the Pennsylvania sections) are far older than both the Green Mountains of Vermont and the White Mountains of New Hampshire.
| Range | Age (Orogeny) | Key Event |
|---|---|---|
| Appalachians | ~480–300 Ma (Ordovician–Permian) | Taconic, Acadian, Alleghenian collisions (Pangaea assembly) |
| Green Mountains | ~100 Ma (Cretaceous) | Late-stage Appalachian overprint / New England uplift |
| White Mountains | ~125 Ma (Early Cretaceous/Jurassic) | White Mountain Magma Series intrusion (monzonite, syenite) |
The Appalachians formed during multiple Paleozoic collisions that built Pangaea. The Greens and Whites are Mesozoic expressions—younger uplift and igneous activity on the rifted margin of the opening Atlantic. The Appalachians' rounded, eroded peaks vs. the Whites' rugged, glacially carved notches reflect this age gap.