A presentation to help students to understand the different forms of land present on the surface of the Earth.

1. CHAPTER# 4
THE EARTH’S LANDFORMS
Prepared By
Wajeeha Nisar Ahmed Khan

4. MOUNTAINS
A mountain is a large landform that rises steeply
above its surroundings.
•It rises to a peak or ridge above 600 meters.
•Earth’s crust is not continuous but broken into pieces called plates.
•These plates float on the semi-liquid mantle and they are
continuously moving.
•Sometimes, when two plates collide, the soft sedimentary rocks
bend or buckle up to form Fold Mountains. This process is known as
Folding.
•Fold Mountains are usually formed over millions of years ago.

5. •Often several mountains grouped together to form a
mountain range.
Examples of Fold Mountains are,
•The Himalaya Mountains in Asia
Alps in Europe
•Rockies in North America

6. HOW DOES FOLD
MOUNTAINS FORM?

7. •Fold Mountains are created due to compressional forces,
which result in the rocks bending and crumpling.

11. •Mountains are also formed when
• volcanoes erupt, pilling successive
• layers of magma on the surface.
•The magma pushes its way into the Earth’s crust
and reaches
the Earth’s surface through cracks.
•When the magma reaches the surface, it flows
out onto the surrounding areas.
•Over the years, the magma piles up to form a
volcanic mountain

12. Examples of Volcanic Mountains are,
Mount Rainer and Mount Saint Helen in US

13. Mount Erebus in Antarctica

15. Mount Fuji in Japan

16. HILL
• A hill is less steep and is lower in elevation than a mountain.
Hills do not rise above 600 meters in height and they have distinct
summits.
They are formed by the buildup of rock debris or sand deposited by
glaciers and wind.
A hill can also be formed when erosion carries away all the soil of a
mountain after millions of years.
A hill can also be formed when successive layers of magma cool and
solidify.
Hills are found in low mountain valleys, valleys, plains and
sometimes even in your backyard!

17. PLATEAU
 A plateau is a raised flat-surfaced landform. It is also appropriately
known as ‘table land’ or flat-topped mountain. Plateaus vary in height,
from topped mountain.
Plateaus vary in height, from about 500 metres to thousands of metres .
Some plateaus are flat while others have been eroded away by water and
wind over millions of years.
Over millions of years, a river will cut through and expose the rock layers
of plateau.

19. Plateaus cover 45% of the Earth’s land surface.
Two-third of the land area in Australia is covered
by the Western Plateau .Much of which is 500
million years old.
In China plateaus cover 25% of the land area.
The Tibetan plateau in China southwest region
is the highest and most extensive plateau in
the world.
The Tibetan plateau is also known
as the ‘ roof of the world, has an average
height of 5,000 metres.
It has 14 mountains that rise above 8,000 metres.

20. Mount Everest and Mount K2 are found
here.
The Tibetan Plateau is still geologically
active and continuous to
rise, gaining about 0.1 centimeters per year
in height.

22. PLAIN
A plain is a widespread flat land which usually does not have any change in height
or elevation.
Plains are usually lower than the land around them.
They can be found along the coast or inland.
They are often well-populated regions because the soil is suitable for cultivation.
Land is flat so that roads and railways are easily built.

23. The Indo-Gangetic Plain is the most populated
region of the world.
It comprises the flood plains of the Indus, Ganges
and Brahmaputra river systems.
Covers the northern and eastern parts of India,
the most populous parts of Pakistan and almost all
of Bangladesh.

25. A valley is a long depression surrounded by
higher grounds on the sides.

26. TYPES OF VALLEYS

27. V-SHAPED VALLEYS
Rivers and streams cut steep-walled and
narrow
depressions in the
land, which from far look like the letter
‘V’.

29. U-SHAPED VALLEYS
Rivers valleys, especially those found in the
mountains or near the North Pole or South Pole
are transformed by glaciers. As the massive
blocks of ice and snow move downhill, the valley
floor and sides are eroded. With the time, the
valleys are pressed into U-shaped valleys.

30. U-SHAPED VALLEY

32. LANDFORMS
MOUNTAINS
• rises steeply above
its surroundings
•Above 600 m iin
height
•Can occur as a single
mountain or together
with many others to
form a mountain
range
•Can be formed due
to the forces in the
Earth
•Can be built up by
solidified magma
PLAIN
• low-lying land
with little change
in elevation
•Flat and suitable
for cultivation
VALLEY
• long narrow
depression found
between higher
grounds
• V-shaped
• U-shaped
HILL
• 600 M OR lower
in height
• has distinct
summit
•Formed by
solidified magma
•Formed by
erossion of
mountains
PLATEAU
• most widespread
landform
•Covers 45% of Land
• varies in height from
500-1000m

33. RELATED QUESTIONS
Q1. HOW DO FOLD MOUNTAINS FORM?
Q2. HOW DO MOUNTAINS FORM DUE TO VOLCANIC ERRUPTION?
Q3. WHICH FORCE CAUSE FOLD MOUNTAINS TO BE FORMED?
Q4. HOW DOES A HILL FORM? WRITE DOWN ITS PROCEDYRE IN A LIST.
Q5. WHERE DO WE FIND HILLS?
Q6. DEFINE THE FOLLOWINGS;
•MOUNTAIN
•HILL
•PLATEAU
•PLAIN
•VALLEY
•U-SHAPED VALLEY
•V-SHAPED VALLEY