Prelims ask
Odd one out against Andes, Alps and Himalayas. Same ancient family of idea as the Urals: worn-down fold belts.
North America · Old fold
Appalachians
- Countries
- United States, continuing into Canada (Quebec, New Brunswick, Newfoundland).
- Length
- About 2,400 km. Exam-safe figure.
- Orientation
- Northeast–southwest.
- Mountain type
- Old fold
- Plates
- Raised in the Alleghanian collision as Laurentia met Gondwana while Pangaea assembled. Now an intraplate, eroded belt.
- Highest peak
- Mount Mitchell, 2,037 m, North Carolina.
- Rivers that rise here
- The ridge-and-valley belt is cut by the Tennessee, Potomac, Susquehanna, Hudson and the Ohio’s headwaters.
- Climate and rain shadow
- Low, rounded, and a weak climatic wall compared with the Rockies. Eastern North America stays humid on both sides.
Mains use
Contrast with young folds: low relief, mineralised ancient roots, little modern volcanism.