1. The Himalayan Mountains

Geologically young & structurally fold mountains.

• Stretch: Indus to Brahmaputra (West-East direction).
• Length: 2,400 Km (Arc shape).
• Width: 400 Km (Kashmir) to 150 Km (Arunachal).

Three Parallel Ranges (तीन समानांतर श्रेणियाँ)

A. Great / Inner Himalayas (Himadri):

• Northernmost & most continuous.
• Avg Height: 6,000 meters.
• Contains highest peaks (Mt. Everest, Kanchenjunga).
• Core is Granite; Perennially snow-bound.

B. Himachal (Lesser Himalaya):

• South of Himadri; Rugged mountain system.
• Altitude: 3,700 – 4,500 meters.
• Prominent Ranges: Pir Panjal (longest), Dhaula Dhar.
• Famous for Valleys: Kashmir, Kangra, Kullu.

C. Shiwaliks (Outer Himalayas):

• Outermost range. Width: 10-50 km.
• Made of unconsolidated sediments (prone to landslides).
• Duns: Longitudinal valleys between Lesser Himalaya & Shiwaliks (e.g., Dehra Dun).

2. The Northern Plain

Formed by interplay of 3 river systems: Indus, Ganga, Brahmaputra.

• Spread: 7 lakh sq. km. Length: 2400 km.
• Highly fertile Alluvial Soil → Densely populated.
• Riverine Islands: Majuli (in Brahmaputra) is the largest inhabited riverine island in the world.

Relief Features (धरातलीय विशेषताएं)

• Bhabar: Narrow belt (8-16km) of pebbles at foot of Shiwaliks. Streams disappear here.
• Terai: Wet, swampy, marshy region south of Bhabar. Thick forests.
• Bhangar: Older alluvium, terrace-like feature. Contains ‘Kankar’.
• Khadar: Newer, younger deposits. Very fertile (Ideal for agriculture).

3. The Peninsular Plateau

Tableland of old crystalline, igneous, metamorphic rocks. (Gondwanaland part).

A. Central Highlands:

• North of Narmada river. Covers Malwa Plateau.
• Bounded by Vindhyas (South) & Aravalis (Northwest).
• East extension: Bundelkhand, Baghelkhand.

B. Deccan Plateau:

• Triangular landmass south of Narmada.
• Slopes gently Eastwards.
• Famous for Black Soil (Deccan Trap) – Volcanic origin.

4. The Indian Desert

• Lies to western margins of Aravali Hills.
• Undulating sandy plain with dunes (Barchans: crescent-shaped).
• Climate: Arid, Low rainfall (< 150 mm/year).
• River: Luni is the only large river.

5. The Coastal Plains

Narrow strips flanking the Peninsular Plateau.

• Western Coast: Between W. Ghats & Arabian Sea. Narrow.
  → Divisions: Konkan (Mumbai-Goa), Kannad, Malabar (South).
• Eastern Coast: Between E. Ghats & Bay of Bengal. Wide & Level.
  → Divisions: Northern Circar, Coromandel Coast.
  → Chilika Lake: Largest salt water lake in India (Odisha).

6. The Islands

A. Lakshadweep Islands (Arabian Sea):

• Small coral islands. Area: 32 sq km.
• HQ: Kavaratti.
• Pitti Island: Uninhabited, Bird sanctuary.

B. Andaman & Nicobar (Bay of Bengal):

• Elongated chain, bigger & scattered.
• Elevated portion of submarine mountains.
• Active Volcano: Barren Island.