Fundamentals of Physical Geography

Geomorphic Processes Notes

Class 11 Geography Chapter 5 – Geomorphic Processes Notes

These Geomorphic Processes Class 11 Notes explain the forces and processes responsible for shaping the Earth’s surface. The chapter discusses endogenic and exogenic processes, weathering, mass wasting, erosion, deposition and soil formation in detail. (NCERT Pages 37–46)

Useful for UPSC, SSC, Railways, State PSC, CUET and CBSE Board Exams, these notes include exact NCERT page references, important geographical concepts, revision tables, FAQs and exam-oriented questions for quick preparation. (NCERT Pages 37–46)

Table of Contents

Chapter Overview

This chapter explains the geomorphic forces responsible for continuous modification of Earth’s surface. It highlights the role of internal and external forces, weathering, mass movements, erosion, deposition and soil-forming processes. (NCERT Pages 37–46)

Major Topics Covered

  • Geomorphic processes
  • Endogenic and exogenic forces
  • Diastrophism
  • Volcanism
  • Weathering
  • Chemical weathering
  • Physical weathering
  • Biological weathering
  • Mass movements
  • Landslides
  • Erosion and deposition
  • Soil formation
  • Soil-forming factors

Geomorphic Processes (NCERT Pages 37–38)

Geomorphic processes are physical and chemical actions that modify Earth’s surface.

Causes of Geomorphic Processes

  • Endogenic forces
  • Exogenic forces

Types of Geomorphic Processes

Type Description
Endogenic Processes Internal Earth forces
Exogenic Processes External surface processes

Endogenic and Exogenic Forces (NCERT Page 37)

Endogenic Forces

  • Originate inside the Earth.
  • Responsible for:
    • Mountain building
    • Upliftment
    • Volcanism
    • Earthquakes
  • Known as land-building forces.

Exogenic Forces

  • Originate from atmosphere.
  • Powered mainly by solar energy.
  • Responsible for wearing down relief.
  • Fill depressions through deposition.

Geomorphic Agents (NCERT Page 38)

Agent Function
Running Water Erosion and deposition
Groundwater Solution and deposition
Glaciers Erosion and transportation
Wind Deflation and deposition
Waves and Currents Coastal erosion and deposition

Role of Gravity (NCERT Page 38)

  • Gravity activates downslope movement.
  • Responsible for:
    • Erosion
    • Transportation
    • Deposition

Endogenic Processes (NCERT Page 38)

Main Sources of Energy

  • Radioactivity
  • Primordial heat
  • Rotational friction
  • Tidal friction

Major Endogenic Processes

Process Description
Diastrophism Crustal deformation
Volcanism Magma movement

Diastrophism (NCERT Page 38)

Type Features
Orogeny Mountain building
Epeirogeny Continental uplift
Earthquakes Local crustal movement
Plate Tectonics Horizontal plate movement

Important Facts

  • Orogeny forms mountains.
  • Epeirogeny forms continents.
  • Faulting and folding occur due to tectonic activity.

Volcanism (NCERT Pages 38–39)

  • Movement of magma toward Earth’s surface.
  • Produces:
    • Intrusive landforms
    • Extrusive landforms

Exogenic Processes (NCERT Page 39)

Exogenic processes derive energy mainly from the Sun and are controlled by climate, gravity and slope.

Main Exogenic Processes

Process Role
Weathering Breakdown of rocks
Mass Movement Downslope movement
Erosion Removal of material
Deposition Accumulation of material

Weathering (NCERT Pages 40–41)

Meaning of Weathering

  • Mechanical disintegration and chemical decomposition of rocks.
  • It is an in-situ process.
  • No major transportation involved.

Types of Weathering

Type Features
Chemical Weathering Decomposition of minerals
Physical Weathering Mechanical breakdown
Biological Weathering Action of organisms

Chemical Weathering (NCERT Page 40)

Process Description
Solution Dissolving minerals
Carbonation Reaction with carbon dioxide
Hydration Addition of water
Oxidation Reaction with oxygen
Reduction Removal of oxygen

Physical Weathering (NCERT Page 40)

Causes

  • Temperature changes
  • Crystal growth
  • Pressure release
  • Wetting and drying

Important Feature

  • Rocks break without chemical change.

Biological Weathering (NCERT Page 41)

Agents

  • Plant roots
  • Earthworms
  • Rodents
  • Termites
  • Human activities

Effects

  • Rock breaking
  • Soil formation
  • Humus development

Mass Movements (NCERT Pages 41–42)

Mass movements are downslope movements caused by gravity.

Main Types

Type Features
Creep Slow movement
Flow Water-assisted movement
Slide Sudden movement
Fall Free fall from slope

Landslides (NCERT Pages 42–43)

Causes of Landslides

  • Steep slopes
  • Heavy rainfall
  • Earthquakes
  • Removal of vegetation
  • Overloading

Types of Landslides

Type Description
Slump Rotational movement
Debris Slide Rapid sliding
Rockslide Sliding of rock mass
Rock Fall Free fall of rocks

Important Fact

  • Himalayas are highly prone to landslides.

Erosion and Deposition (NCERT Page 43)

Erosion

  • Removal and transportation of weathered materials.

Agents of Erosion

  • Running water
  • Wind
  • Glaciers
  • Waves
  • Groundwater

Deposition

  • Settling of transported materials.
  • Occurs when transporting agents lose energy.

Soil Formation (NCERT Pages 44–45)

Soil

  • Dynamic natural body.
  • Contains:
    • Mineral matter
    • Organic matter
    • Water
    • Air

Pedogenesis

  • Process of soil formation.

Soil-Forming Factors (NCERT Pages 44–45)

Factor Role
Parent Material Source material
Topography Drainage and slope
Climate Controls weathering
Biological Activity Humus formation
Time Soil maturity

Important Topics

Important Topic NCERT Page
Geomorphic processes 37–38
Endogenic forces 37–38
Exogenic processes 39
Weathering 40–41
Mass movements 41–43
Soil formation 44–45

Important Geographical Concepts and Terms

Concept Explanation NCERT Page
Gradation Wearing down of relief 37
Denudation Overall stripping process 39
Orogeny Mountain building 38
Pedogenesis Soil formation 44
Eluviation Removal of soil materials 45

Important Questions

Very Short Answer Questions

  1. What are geomorphic processes? (NCERT Page 37)
  2. Define gradation. (NCERT Page 37)
  3. What is denudation? (NCERT Page 39)
  4. Define weathering. (NCERT Page 40)
  5. What is exfoliation? (NCERT Page 41)

Short Answer Questions

  1. Differentiate between endogenic and exogenic forces. (NCERT Pages 37–39)
  2. Explain geomorphic agents. (NCERT Page 38)
  3. Describe types of weathering. (NCERT Pages 40–41)
  4. Explain biological weathering. (NCERT Page 41)
  5. Describe causes of landslides. (NCERT Pages 42–43)

Long Answer Questions

  1. Explain geomorphic processes and their significance. (NCERT Pages 37–39)
  2. Discuss physical, chemical and biological weathering. (NCERT Pages 40–41)
  3. Explain mass movements and landslides. (NCERT Pages 41–43)
  4. Describe the process of soil formation. (NCERT Pages 44–45)

FAQs

1. What are geomorphic processes?

Processes that shape and modify Earth’s surface are called geomorphic processes. (NCERT Pages 37–38)

2. What is denudation?

Denudation is the stripping and lowering of Earth’s surface through weathering and erosion. (NCERT Page 39)

3. What are the main types of weathering?

Chemical, physical and biological weathering are the three main types. (NCERT Pages 40–41)

4. Why are Himalayas prone to landslides?

Due to steep slopes, tectonic activity and heavy rainfall. (NCERT Pages 42–43)

5. What is pedogenesis?

Pedogenesis is the process of soil formation. (NCERT Page 44)

Quick Revision Summary

  • Endogenic forces build relief.
  • Exogenic forces wear down relief.
  • Geomorphic agents include rivers, glaciers and wind.
  • Diastrophism includes orogeny and epeirogeny.
  • Weathering is an in-situ process.
  • Chemical weathering includes carbonation and oxidation.
  • Biological weathering supports soil formation.
  • Landslides are gravity-induced movements.
  • Erosion transports weathered materials.
  • Pedogenesis means soil formation.
  • Climate is a major soil-forming factor.
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