Official Answer Key & Detailed Solution
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Correct Answer: Option (D) — 1, 2, 3 and 4
Concept & Option Breakdown
Standard Reference VerifiedAll four geological and morphological features serve as evidence that the Himalayas are young fold mountains:
- Deep V-shaped valleys and gorges indicate ongoing rapid vertical river incision in an uplifting terrain.
- U-turn river courses (hairpin bends/syntaxial bends) reflect ongoing tectonic bending and antecedent drainage.
- Parallel mountain ranges (Himadri, Himachal, Shiwalik) reflect successive compressive phases of folding.
- Steep slopes and high gradients with frequent landslides indicate active tectonic instability and youthful topography.
In geological terms, young fold mountains undergo active orogeny and rapid erosion, exhibiting all features: steep gradients, deep canyons/gorges, parallel folded ridges, and syntaxial river loops.
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