Physical Features of India Class 9 Flashcards

Tectonic Plate Movements

• Tectonic plate movements cause stresses leading to folding, faulting, and volcanic activities.
• Types of movements include convergent, divergent, and transform boundaries.

Gondwana Land

• The Indian peninsula, oldest part of the subcontinent, was part of Gondwana land.
• Countries included: India, Australia, South Africa, South America, and Antarctica.

Movement of Gondwana Land

• Convectional currents split Earth’s crust; Indo-Australian plate separated from Gondwana.
• Indian plate migrated northward, colliding with the Eurasian plate.

Himalayas Formation

• Collision of Indian and Eurasian plates folded sedimentary rocks from the Tethys Sea into the Himalayas.

Northern Plains Formation

• Himalayas created a depression filled by sediments from rivers, forming alluvium-rich northern plains.

Stable and Unstable Landforms

• The peninsular plateau recognized as most stable landform.
• Himalayan mountains identified as most unstable due to tectonic activity.

Physiographic Divisions of India

• Divided into six main regions: Himalayan mountains, Northern plains, Peninsular plateau, Indian Desert, Coastal Plains, and Islands.

Introduction to the Himalayan Mountains

• Extend 2,400 km from the Indus to the Brahmaputra, with varying widths (400 km in Kashmir to 150 km in Arunachal Pradesh).
• Consist of three ranges: Himadri, Himachal, and Shiwaliks.

Himadri Range

• Continuous range with loftiest peaks (average height of 6 km).
• Composed of granite, perennially snow-bound, contains many glaciers.

Himachal Range

• Located south of Himadri, consists of compressed and altered rocks.
• Altitude range: 3.7 km to 4.5 km; home to valleys such as Kangra and Kullu.

Shiwaliks Range

• Ranges from 0.9 km to 1.1 km in altitude, width 10-50 km.
• Composed of unconsolidated sediments; includes valleys like Dehra Dun.

Tallest Peaks of the Himalayas

• Mount Everest (8,848 m, Nepal) and Kanchenjunga (8,598 m, India) noted as the highest peaks.

Longitudinal Divisions of the Himalayas

• Divided by rivers into Punjab, Kumaon, Nepal, and Assam Himalayas.

Purvachal or Eastern Hills

• Eastward of the Brahmaputra, comprising northeastern hills like Manipur, Mizo, and Naga hills.

Introduction to the Northern Plains

• Formed by sediment deposition from Indus, Ganga, and Brahmaputra rivers; covers 700,000 km².
• Characterized by alluvial soil and extensive river systems.

Riverine Divisions of the Northern Plains

• Three main sections: Punjab plains (Indus region), Ganga plains (Haryana to West Bengal), and Brahmaputra plains (primarily Assam).

Relief Variation Divisions of the Northern Plains

• Bhabar: Pebble deposits along Shiwalik slopes.
• Terai: Wet, marshy area previously forested.
• Bhangar: Largest area with calcareous soil (Kankar).

Introduction to the Peninsular Plateau

• Comprises old crystalline and metamorphic rocks, the oldest landmass, originally part of Gondwana.

Central Highlands

• North of Narmada River, consisting mainly of the Malwa plateau; influenced by nearby ranges like Vindhyan.

Deccan Plateau

• Triangular region south of Narmada, characterized by distinct hill ranges and separation from Chotanagpur plateau.

Ghats of India

• Western Ghats: Parallel to western coast, 0.9 km to 1.6 km elevation, rainfall inducing clouds.
• Eastern Ghats: Discontinuous, lower elevation (0.6 km), dissected by rivers.

Distinct Features of the Deccan Plateau

• Notable for Deccan Trap and black soil of volcanic origin; bordered by Aravali hills.

Indian Desert

• Located east of Aravalis, characterized by sandy plains, arid climate, minimal rainfall, and intermittent streams.

Coastal Plains

• Surround the peninsular plateau, separated by Arabian Sea and Bay of Bengal; notable rivers form deltas.

Islands of India

• Two prominent groups: Lakshadweep (southeast, diverse flora and fauna) and Andaman and Nicobar Islands (strategically significant).

Resources from Physiographic Features

• Mountains offer water and forest resources; northern plains support agriculture; plateaus provide minerals; coastal regions offer fish and ports; diverse physical features foster potential for future development.

Explore key concepts related to the physical features of India through these flashcards. Learn about tectonic plate movements, the Gondwana land, and their impact on India's geography. Ideal for Class 9 students looking to enhance their understanding of geography.