🏔️ PART 1: Mountains
A mountain is a large natural elevation of the land surface, typically
rising steeply and to a notable height above surrounding terrain. Generally heights above 600 m from base
are considered mountains.
Types of Mountains
| Type |
Formation |
Shape / Features |
Examples |
| Fold Mountains |
Formed by compression of Earth's crust — tectonic plates push against each other; sedimentary
layers fold up like a carpet being pushed from both sides. |
Long, linear ranges; parallel ridges and valleys; gentle to steep slopes; contain folded
sedimentary rocks |
Himalayas (India-China; youngest and highest), Alps (Europe), Rockies (North America), Andes
(South America), Appalachians (USA — old, worn down) |
| Block Mountains (Horsts) |
Formed by faulting — blocks of land between parallel faults are uplifted (horst) or the
surrounding blocks sink (graben/rift valleys) |
Steep sides (fault scarps), flat tops; often with rift valleys alongside |
Vosges (France), Black Forest (Germany), Sierra Nevada (USA), Vindhyas and Satpuras (India) |
| Residual / Relict Mountains |
Formed from ancient mountains that have been eroded over millions of years — only resistant rock
remains as isolated hills or ranges |
Low, rounded, isolated; no clear fold or fault structure visible |
Aravallis (India — world's oldest fold mountains, now residual), Nilgiris (India), Eastern
Highlands of Australia, Sierras de la Ventana (Andes foothills) |
Examples from the World and India
- World Examples: Himalayas, Alps, Andes, Rockies (fold); Vosges, Black Forest (block);
Aravallis (residual).
- India: Himalayas (fold — youngest), Aravallis (residual — oldest), Vindhyas &
Satpuras (block/structural).
🏝️ PART 2: Plateaus
A plateau (also called a tableland) is an elevated, flat-topped landform
with steep sides. It rises sharply above the surrounding land on at least one side.
Types of Plateaus
| Type |
Formation |
Examples |
| Intermont Plateau (Mountain plateau) |
Surrounded by mountains on all sides. Formed when folding creates basins enclosed by mountain
ranges. |
Tibetan Plateau (world's highest — "Roof of the World"; avg ~4,500 m), Bolivian Plateau, Plateau
of Mexico |
| Volcanic (Lava) Plateau |
Formed by repeated outpourings of lava from volcanic eruptions that spread out and solidify in
flat layers |
Deccan Plateau (India — largest lava plateau; basalt rock/black soil); Columbia Plateau (USA);
Antrim Plateau (Ireland) |
| Dissected Plateau |
An older plateau that has been deeply cut by river erosion into rugged, hilly terrain |
Chota Nagpur Plateau (India; deeply cut by rivers); Appalachian Plateau (USA) |
Important World Plateaus: Canadian Shield, Tibetan Plateau,
Brazilian Highlands, Patagonian Plateau (Argentina), Iranian Plateau, Mongolian Plateau.
🌾 PART 3: Plains
A plain is a broad, flat or gently undulating lowland area. Plains are
the most densely populated landforms — they support intensive agriculture and large settlements.
Types of Plains
| Type |
Formation |
Examples |
| Structural Plains |
Formed by large flat rock strata exposed on Earth's surface — no major folding or faulting;
gentle slopes |
Great Plains of USA, Siberian Plain (Russia) |
| Depositional Plains (Alluvial) |
Formed by deposition of sediments by rivers, glaciers, or wind. Most fertile plains — alluvial
deposits are rich in nutrients. |
Indo-Gangetic Plain (India — formed by Himalayan rivers); Amazon Basin (South America);
Mississippi Plain (USA); Nile Delta (Egypt) |
📝 Quick Revision Facts
| Landform |
Key Fact |
| Youngest fold mountains |
Himalayas (India); Alps (Europe); Andes (South America) |
| World's oldest mountains |
Aravallis (India) — now residual/relict mountains |
| Block mountains formed by |
Faulting; uplifted block = Horst; sunken block (valley) = Graben/Rift Valley |
| World's highest plateau |
Tibetan Plateau ("Roof of the World"; avg ~4,500 m) |
| Largest lava plateau in India |
Deccan Plateau (basalt/black soil) |
| Most fertile and densely populated plains |
Depositional alluvial plains (e.g., Indo-Gangetic Plain) |
| Rift Valley — example |
Rhine Rift Valley (Germany); East African Rift Valley; Narmada Valley (India) |
📌 Chapter Summary
- Mountains: Fold (compression — Himalayas, Alps, Andes, Rockies); Block (faulting — Vosges,
Vindhyas); Residual (erosion — Aravallis).
- Plateaus: Intermont (enclosed by mountains — Tibet); Volcanic/Lava (lava layers — Deccan Plateau,
Columbia); Dissected (eroded — Chota Nagpur). World examples: Canadian Shield, Brazilian Highlands,
Iranian Plateau, Mongolian Plateau.
- Plains: Structural (flat exposed rock); Depositional/Alluvial (river deposits — most fertile;
Indo-Gangetic Plain). Most densely populated landforms.