Major Landforms of the Earth

1. Name the four types of mountains. Give one example of each.

There are three types of mountains

• Fold mountains - example Himalayas,Andes, Alps and Rockies

• Block mountains - example Vosges, Black Forest, Vindhya and Satpura

• Volcanic mountains - example Mount Vesuvius and Mount Kilimanjaro

2. Define a plateau. By what other name is it called?

A plateau is a large mass of comparatively flat land that rises abruptly from the surrounding area. It is also called a tableland.

3. Distinguish between an intermontane plateau and a piedmont plateau.

	Intermontane plateaus	Piedmont Plateaus
1	They are enclosed by mountain ranges	They are formed at the foot of mountains
2	Example - tibet, Bolivia, Great Basin in USA, Iran	Example - Patagonia in Argentina

4. How are volcanic plateaus formed? Give an example.

Volcanic eruptions lead to the formation of layers of lava sheets which solidify to form Volcanic Plateaus.  Example - Deccan in India.

5. How are erosional plains and depositional plains different from each other?

Erosional plains have been formed as a result of the continuous wearing down of highlands by the agents of erosion while depositional plains have been formed by the deposition of silt, sand and clay by rivers in low lying areas.

6. Distinguish between endogenic process and exogenic process.

	Endogenic process	Exogenic process
1	The forces act from inside the earth	The forces act on the surface of the earth
2	They are also called tectonic/internal processes	They are also called external processes
3	They lead to folding, faulting, volcanic eruptions and earthquakes	They help in weathering, erosion, transportation and deposition of the weathered and eroded material

7. Explain the formation of fold mountains. Differentiate between young fold mountains and old fold mountains giving examples of each.

Fold mountains are formed by the wrapping or folding of the earth's crust due to compressional forces. The compressional forces generally occur when tectonic plates converge. 

	Young Fold Mountains	Old Fold Mountains
1	They are high	They are low in height
2	They have steep slopes	They have gentle slopes
3	They have sharp pointed peaks	They have rounded peaks
4	Example -  Himalayas, Alps, Rockies and and Andes	Example -  Urals, Aravali and Appalachians

8. How are volcanic mountains formed? Mention their characteristics. Give relevant examples.

They are a result of repeated volcanic activities over a period of time. Hot molten lava/magma reaches the earth’s surface through a vent, when extreme pressure builds up within the earth. On reaching the surface magma, ash and cinder accumulates and solidifies. Volcanic mountains are shaped like a cone. Example - Mt Vesuvius and Mt Kilimanjaro.

9. Explain how rift valleys are formed. Name the three major rift valleys of the world.

When the land between two fault lines Sab size, it forms a rift valley with a flat bottom and steep sides bounded by block mountains. They are deep with steep vertical walls.

African Rift Valley, Rhine river valley and Narmada river valley are three major rift valleys of the world.

10. Compare erosional and structural plains. Give examples.

	Erosional Plains	Structural Plains
1	Also called tectonic plains, they have been formed in areas where the rock layers on the earth’s crust are aligned almost horizontally	They have been formed as a result of the continuous wearing down of file and by the Agents of erosion

11. Compare block mountains with volcanic mountains. State their formation and characteristics. Give relevant examples of each.

	Block Mountains	Volcanic Mountains
1	They are formed due to upliftment or subsidence of blocks along the faults found on the crust due to forces of compression	They are formed due to cooling and solidification of hot,  molten lava
2	They are shaped like a block	They are shaped like a cone
3	Example -  Vosges, Black forest, Vindhya, Satpura	Example -  Mt. Vesuvius, Mt. Kilimanjaro
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12. Explain why mountains are considered an important natural resource.

• Mountain glaciers provide water for irrigation and hydroelectricity throughout the year

• They provide  river valleys and gentle slopes for cultivation of crops and fruits

• They provide minerals for industries and stones for construction

• They hey provide home for wildlife

• They provide forest products and grazing grounds for sheep

• They provide scenic beauty and tourism

• They act as a climatic barrier

13. How are plateaus useful to us?

• They provide minerals

• They provide water falls which can be utilised for hydroelectricity

• They provide fertile land for cultivation of cotton and sugarcane

• They provide scenic beauty for tourism

14. Old fold mountains have rounded peaks while young fold mountains have sharp, pointed peaks. Why?

Young Fold mountains are formed due to folding of earth's crust. So, they have sharp pointed peaks. Whereas old fold mountains have rounded peaks because they have undergone erosion for millions of years. 

15. Volcanic plateaus are suitable for the cultivation of cotton & sugarcane. Why?

Volcanic plateaus have black soil which is the best for the growth of cotton and sugarcane.

16. A number of hydel power stations are located in the plateau regions. Why?

Rivers in the plateaus form a number of waterfalls as they drop abruptly down the steep slopes. These waterfalls are utilised for generating hydroelectricity.

17. Plains are the most thickly populated regions of the world. Why?

• They provide fertile soil for agriculture.

• They provide flat land for construction of transport networks, buildings and industries