Consider the following information:
| Region | Name of the mountain range | Type of mountain | |
|---|---|---|---|
| 1. | Central Asia | Vosges | Fold mountain |
| 2. | Europe | Alps | Block mountain |
| 3. | North America | Appalachians | Fold mountain |
| 4. | South America | Andes | Fold mountain |
In how many of the above rows is the given information correctly matched?
Answer & explanation
Answer: (b) Only two
Rows 3 and 4 are right: the Appalachians and the Andes are fold mountains raised where plates converged. Row 1 is wrong twice over — the Vosges are in Europe (France) and are a block mountain beside the Rhine rift valley; row 2 is wrong because the Alps are young fold mountains, not block mountains.
- ✗ 1. The Vosges are in north-eastern France, west of the Rhine Graben — a sunken block of crust. They are a classic block (horst) mountain of Europe, not a fold range of Central Asia.
- ✗ 2. The Alps belong to the young zone of continental collision that runs from the Himalayas to Europe; they are fold mountains, not block mountains.
- ✓ 3. The Appalachians formed in continental collisions 500–300 million years ago; their sedimentary layers were folded and faulted. They are old, worn-down fold mountains.
- ✓ 4. The Andes were raised as the oceanic Nazca Plate pushed under the South American Plate — a convergent-boundary fold range.
Remember · Fold: Himalayas, Alps, Andes, Rockies (young); Appalachians, Aravallis, Urals (old). Block: Vosges and Black Forest on either side of the Rhine rift valley.
Sources
- NASA MODIS Image Gallery: The Vosges Mountains, the Black Forest, and the Rhine Valley ↗ “The Rhine River Valley in that area is known to geologists as the Rhine Graben. A graben is an elongated block of Earth’s crust that has sunk relative to the surrounding blocks.”
- US National Park Service: Convergent Plate Boundaries — Collisional Mountain Ranges ↗ “The Appalachian Mountains formed during a collision of continents 500 to 300 million years ago. In their prime they probably had peaks as high as those in the modern zone of continental collision stretching from the Himalayas in Asia to the Alps in Europe.”
- USGS: This Dynamic Earth — Understanding plate motions ↗ “In turn, the overriding South American Plate is being lifted up, creating the towering Andes mountains, the backbone of the continent.”
Question and answer: UPSC's official GS Paper I (2024, Series A) — paper ↗ · answer key ↗. Explanation: Minimalist IAS, checked 30 Sept 2026 (how we verify). ·