(Source: VI NCERT Geography Chapter - 6)
Chapter 6 - Major Landforms of the Earth
Chapter 6 - Major Landforms of the Earth
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A hill is a land surface that rises higher than the surrounding areas.
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A hill with an elevation of more than 600 metres is termed as mountain.
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Based on elevation and slope we can group different landforms as Mountains,
Plains and Plateaus.
It
is natural elevation of the earth surface.
-
Glaciers are the mountains with permanently frozen rivers of ice.
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Range is the arrangement of mountains in a line.
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There are three types of mountains
1.Fold
mountains
2.Block
mountains
3.Volcanic
mountains
-The
Himalayan Mountains and the Alps are young fold mountains with rugged relief
and high conical peaks.
-The
Aravali range in India is one of the oldest fold mountain systems in the world.
-The
Appalachians in North America and the Ural mountains in Russia have rounded
features and low elevation. They are very old fold mountains.
-Block
Mountains are
created when large areas are broken and displaced vertically. The uplifted
blocks are termed as horsts and the lowered blocks are called graben.
-The
Rhine valley and the Vosges mountain in Europe are examples of such
mountain
systems.
-Volcanic
mountains are formed due to volcanic activity.
-Mt.Kilimanjaro
in Africa and Mt.Fujiyama in Japan are examples of such mountains.
-The
mountains are a storehouse of water.
-Many
rivers have their source in the glaciers in the mountains.
-Water
from the mountains is also used for irrigation and generation of
hydro-electricity.
-The
river valleys and terraces are ideal for cultivation of crops.
-Mountains
have a rich variety of flora and fauna.
-Mountains
provide an idyllic site for tourists.
-Mauna
Kea (Hawaii) in the Pacific Ocean is an undersea mountain. It is higher
than Mount Everest being 10,205 metres high.
-The
Himalayas, the Alps and the Andes are mountain ranges of Asia, Europe and South
America, respectively.
PLATEAUS
-It
is an elevated flat land.
-It
is a flat-topped table land standing above the surrounding area.
-A
plateau may have one or more sides with steep slopes.
-The
height of plateaus often varies from few hundred metres to several thousand
metres.
-Plateaus,
like mountains may be young or old.
-The
Deccan plateau in India is one of the oldest plateaus.
-The
East African Plateau in Kenya,Tanzania and Uganda and the Western plateau of
Australia are other examples.
-The
Tibet plateau is the highest plateau in the world with a height of 4,000 to
6,000 metres above the mean sea level.
-Plateaus
are very useful because they are rich in mineral deposits. As a result, many of
the mining areas in the world are located in the plateau areas.
-The
African plateau is famous for gold and diamond mining.
-In
India huge reserves of iron, coal and manganese are found in the Chhotanagpur
plateau.
-In
the plateau areas, there may be several waterfalls as the river falls from a
great height. In India, the Hundru falls in the Chhotanagpur plateau on
the river Subarnarekha and the Jog falls in Karnataka are examples of
such waterfalls.
-The
lava plateaus are rich in black soil that are fertile and good for cultivation.
-Many
plateaus have scenic spots and are of great attraction to tourists.
PLAINS
-Plains
are large stretches of flat land.
-They
are, generally, not more than 200 metres above mean sea level.
-Most
of the plains are formed by rivers and their tributaries. The rivers flow down
the slopes of mountains and erode them. They carry forward the eroded material.
Then they deposit their load consisting of stones, sand and silt along their
courses and in their valleys. It is from these deposits that plains are formed.
-Generally,
plains are very fertile.
-These
plains are very thickly-populated regions of the world. Plains are the most
useful areas for human habitation. There is great concentration of people as
more flat land is available for building houses, as well as for cultivation.
-In
India, the Indo-Gangetic plains are the most densely populated regions
of the country.