Major Landforms of the Earth
ICSE Class 6 · Geography · Chapter 3
What this chapter covers
- Types of landforms
- Forces that shape the land: endogenous and exogenous processes
- Mountains
- Valleys
- Plateaus
- Plains
- Landforms on the world map and in people's lives
Key definitions
Endogenous processes are the forces that act from inside the Earth and build up or break the land.
Exogenous processes are the forces that act on the surface of the Earth and wear the land down.
Folding is the bending of rock layers into up-folds and down-folds when they are squeezed from two sides.
Fold mountains are mountains formed when layers of rock are squeezed and bent into folds by forces from inside the Earth.
Young fold mountains are fold mountains that were formed recently in the Earth's long history.
Old fold mountains are fold mountains that were formed a very long time ago and have been worn down by wind, rain and rivers.
Faulting is the cracking of rocks into large blocks when they are pulled apart or pushed together by forces inside the Earth.
Block mountains are mountains formed when a large block of land is pushed up between two faults, or when the land on both sides sinks down.
Volcanic mountains are mountains formed when lava, ash and rock from a volcano pile up layer upon layer around the opening.
Residual mountains are the worn-down remains of old mountains or plateaus that wind, rain and rivers have eroded over a very long time.
Structural plains are plains formed when a part of the sea floor or low land is slowly raised up by forces inside the Earth.
Erosional plains are plains formed when wind, rain, rivers or ice wear down high land over a very long time until it becomes almost flat.
Key points
- A landform is a natural shape of the Earth's surface; the main types are mountains, valleys, plateaus and plains.
- Endogenous processes act from inside the Earth and build land; exogenous processes act on the surface and wear it down.
- Fold mountains form by folding: young ones (Himalayas, Alps, Rockies, Andes, Atlas, Great Dividing Range) are high and sharp; old ones (Urals, Appalachians, Aravallis) are low and rounded.
- Block mountains form by faulting: Black Forest, Vosges, Vindhyas.
- Volcanic mountains form from piled-up lava and ash: Kilimanjaro and Fujiyama.
- Rift valleys form when land sinks between faults: Rhine, Narmada, Nile.
- Plateaus are high flat-topped lands rich in minerals: Deccan, Tibetan, East African.
- Plains are low flat lands, mostly built by rivers: the plains of North America and the Gangetic Plain.
- Mountains give water, forests and protection; plains hold most of the world's people and farms.