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 ?
- (a) Only one
- (b) Only two ✓ UPSC's answer
- (c) Only three
- (d) All four
Why the answer is (b)
• Row 3 is correct: the Appalachians of eastern North America are ancient (Palaeozoic) fold mountains, now worn down.
• Row 4 is correct: the Andes of South America are young fold mountains formed by subduction of the Nazca plate under the South American plate.
• Row 1 is wrong twice over: the Vosges are in eastern France, Europe, not Central Asia, and they are block mountains (horsts) flanking the Rhine rift valley.
• Row 2 is wrong: the Alps are young fold mountains raised by the collision of the African and Eurasian plates, not block mountains.
• Hence two rows are correct, option (b).
Why the other options are wrong
- (a) Only one
- Two rows (Appalachians and Andes) are correct, not one.
- (c) Only three
- Rows 1 and 2 are both wrong, so the count is two.
- (d) All four
- The Vosges and Alps rows are incorrect.
Asked in the GS Paper I of the UPSC Civil Services Preliminary Examination 2024, held on 16 June 2024. Question and answer key: Union Public Service Commission. Explanation: UPSC Answer Check.