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Geetika AroraAIR 22· 2025

Question Q.15Discuss, ExplainGS1GS1

Discuss the concept of isostasy and explain its role in shaping Earth's major landforms. (15 marks, 250 words)

Open scan (p.35)

Introduction

ISOSTASY - is a geographical phenomenon, where the process of 'erosion' and 'deposition' takes place together; leading to balance and formation/shaping of different Earth's landforms.

25 words

Main Body

Concept of Isostasy:-

1As per this concept, there exist 'natural balance' between Earth's formation & destruction.
2The Natural balance leads to a 'static state' and balance in the geological sphere.
3The concept is applicable in geomorphology to identify factors for different Natural phenomenon like Earthquake, landslides, Mountain Building, Continental building.

[Seminal concept in study of Earth's evolution, in current shape/size etc.]

Role of Isostasy in shaping major Earth's landforms:-

1The forces of [deposition] leading to formation of Himalayas:- The continent-continent convergence lead to shrinking of Tethys sea. The Himalayas uplifted, with three collisions (Shivaliks, lesser Himalayas, Greater Himalayas)
2Desert landforms like Zeugens, Yardangs, Peneplain, Pediplain excluding Mushroom rocks etc. due to concept of Isostasy.
3The landforms formed by Running water includes:- U shaped valley & V shaped valley. Gorges & canyons (due to undercutting of rivers)

(eg) Gandikota canyon of south India.

Delta formation, at the mouth of River, merging into ocean: (eg) Sunderban Delta due to Ganga-Brahmaputra confluence

4Landforms formed due to [Vulcanism] include - Dykes, Sills, Batholith, Phacolith, Phorolith, Ash and cinder cone; Basaltic large [illegible] volumes etc. (eg) Hurumian Plains.
5Glacial landforms formation like Eskers, Fjords, U shaped valley, Moraines etc.
202 words7 paragraphs

Conclusion

Thus, the 'Isostasy' as a concept helps in explaining various landforms formation on planet Earth.

15 words

  • Clear conceptual definition
  • Good linkage to geomorphological phenomena

Topper

Geetika Arora

AIR 222025

Subject & Paper

GS1GS1

Topic

Physical Geography

Geomorphology

Isostasy

Writing Stats

242

Total words

7

Paragraphs

analytical

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