This MCQ module is based on: Introduction to India’s Physical Diversity & The Himalayan Mountains
Introduction to India’s Physical Diversity & The Himalayan Mountains
Study Notes and Summary
Chapter Notes:
Introduction to India’s Physical Diversity:
India is a vast country with varied landforms, possessing practically all major physical features of the Earth: mountains, plains, deserts, plateaus, and islands.
Geological Formations:
Peninsular Plateau: Constitutes one of the ancient landmasses on the Earth’s surface; considered one of the most stable land blocks. Composed of igneous and metamorphic rocks with gently rising hills and wide valleys.
Himalayas and Northern Plains: Most recent landforms. The Himalayas form an unstable zone, representing a very youthful topography with high peaks, deep valleys, and fast-flowing rivers.
Northern Plains: Formed of alluvial deposits.
Major Physiographic Divisions (Overview):
The Himalayan Mountains
The Northern Plains
The Peninsular Plateau
The Indian Desert
The Coastal Plains
The Islands
The Himalayan Mountains:
Formation: Geologically young and structurally fold mountains.
Extent: Stretch over the northern borders of India. Form an arc covering about 2,400 km. Their width varies from 400 km in Kashmir to 150 km in Arunachal Pradesh.
Altitude Variation: Show greater altitude variation in the eastern half than in the western half.
Parallel Ranges: Consist of three parallel ranges in its longitudinal extent.
1. Greater or Inner Himalayas (Himadri):
Northernmost range.
Most continuous range consisting of the loftiest peaks with an average height of 6,000 metres.
Contains all prominent Himalayan peaks (e.g., Mt. Everest, Kanchenjunga).
Folds are asymmetrical in nature. The core is composed of granite.
Perennially snow-bound, source of many glaciers.
2. Lesser Himalaya or Himachal:
South of the Himadri.
Highly compressed and altered rocks.
Altitude: Between 3,700 and 4,500 metres.
Average width: 50 km.
Pir Panjal range: The longest and most important range.
Dhaula Dhar and Mahabharat ranges: Other prominent ranges.
Famous for hill stations (e.g., Kashmir, Kangra, Kullu valleys).
3. Shiwaliks (Outer Himalayas):
Outermost range of the Himalayas.
Width: 10-50 km.
Altitude: Between 900 and 1,100 metres.
Composed of unconsolidated sediments brought down by rivers from the main Himalayan ranges.
Valleys are covered with thick gravel and alluvium.
Duns: Longitudinal valleys lying between the Lesser Himalayas and the Shiwaliks (e.g., Dehra Dun, Kotli Dun, Patli Dun).
Divisions based on River Valleys (Regional Divisions):
Punjab Himalayas: Between Indus and Sutlej.
Kumaon Himalayas: Between Sutlej and Kali.
Nepal Himalayas: Between Kali and Tista (largest part).
Assam Himalayas: Between Tista and Dihang.
Purvachal or Eastern Hills and Mountains:
Marked by the Dihang gorge, the Himalayas bend sharply to the south and spread along the eastern boundary of India.
These hills are composed of strong sandstones and limestones, largely covered with dense forests.
Comprise the Patkai hills, Naga hills, Manipur hills, and Mizo hills.
Practice MCQs
Assessment Worksheets
This assessment will be based on: Introduction to India’s Physical Diversity & The Himalayan Mountains
Olympiad Focus & Application
Real-Life Connections & General Knowledge:
The Himalayas are the world’s youngest and highest mountain range, crucial for India’s climate (monsoon barrier), water resources (origin of major rivers), and biodiversity.
The formation of the Himalayas is a prime example of plate tectonics (collision of Indo-Australian and Eurasian plates).
The concept of “duns” is a unique geomorphological feature specific to the Himalayan foothills, often associated with famous valleys and towns.
Case-based Scenarios & Reasoning:
Scenario: A major earthquake occurs in the Himalayan region. Explain why this area is geologically unstable and prone to such events, linking it to its formation and composition.
Reasoning: This tests understanding of plate tectonics and geological stability.
Scenario: Compare the Himadri and Shiwaliks ranges. If you were planning an expedition, what geographical differences (altitude, terrain, vegetation) would influence your choice of range for a particular activity (e.g., high-altitude climbing vs. trekking in foothills)?
Reasoning: This requires a comparative analysis of the physical characteristics of different Himalayan ranges.
Conceptual Application:
Plate Tectonics: Detail how the collision of tectonic plates led to the upliftment and folding of the Himalayas, explaining their “youthful” and “unstable” nature.
Orographic Effect: Explain how the Himadri acts as a barrier to monsoon winds, causing heavy rainfall on its southern slopes and influencing the climate of the Northern Plains.
Comparative & Analytical Points:
Distinguish between the longitudinal divisions (Himadri, Himachal, Shiwaliks) and the regional divisions (Punjab, Kumaon, Nepal, Assam Himalayas) of the Himalayas.
Analyze the differences in altitude variation between the eastern and western parts of the Himalayas and its implications for climate and human activity.
Discuss how the unconsolidated sediments in the Shiwaliks make them more susceptible to landslides compared to the older, more stable Himadri.
