Major Landforms of the Earth- Class 6th- Long Questions and Answers 

Major Landforms of the Earth – 9 Long Questions and Answers 

1. How do forests help us?

Ans. The forests help us in many ways- 

1. They help us to breath clean air 
2. Forest is a home of many plant and animal species.
3. They bring balance to the earth climate by keeping it cool
4. Helps in making rain
5. They prevent flooding by holding the soil with help of deep roots 
6. Forest helps in blocking the wind.
7. Forest provides fuel, fodder, shelter and other products like gum, raisins, etc.
8. The forests are the base for survival of people living on mountains.

2. Differentiate between the internal and external processes.

Ans. Internal process– The continuous movement inside the earth is called internal process, which leads to the upliftment and sinking of the earth’s surface at several places and changes the shape of the surface.

External processes – The external process is the continuous changing on the earth’s surface with the help of several agents like- ice, water and wind. It results into wearing down and rebuilding of the land surface.

Q. 3. What are the types of mountains?

Ans. Mountains can be divided into three types They are as follows:

Block mountains 

• They are created when large areas are broken and displaced vertically. For
• example-the Vosges mountain.

Volcanic mountains 

• They are formed by volcanic activities. 
• They are formed by the deposition o lava. For example-Mt. Kilimanjaro.

Folded mountain 

• Folded mountains are with rugged relief and high conical peaks. For example- Himalayan mountains and Alps, while others with rounded features and low elevation like-Ural mountains.

Q. 4. Write about features of following.

(a) Plateau

(b) Mountain

Ans. (a) Plateau- 

• A plateau may have one or more sides with steep slopes. 
• It is a flat-topped tableland standing above the surrounding area. 
• Plateaus may be young or old. The height of plateaus varies from a few hundred meters to several thousand meters.

(b) Mountain- 

• A mountain is a natural elevation of the earth’s surface more than 600 metres.
• Mountains are of three types. They are- Fold mountains, Block mountains and the
• Volcanic mountains.

Q. 5. Write any Three benefits of Plateau and any two Benefits of Plains.

Ans. Benefit of Plateau :

1. Plateaus have rich mineral deposits.
2. Most precious metals like gold, silver, etc. are also obtained from mines found in the plateau regions.
3. Plateau region soil is made up of lava, which is good for crops like cotton.

Benefits of Plains :

1. They provide us with ideal sites for settlement.
2. Plains are the food bowl of a region.

Q.6. Describe the features of a volcano.

Ans. Features of volcano are as follows- 

1. A volcano is an opening on the surface of the Earth from which magma, associated gasses and ash erupt.
2. Volcano has a magma chamber that is a huge bottomless pot of molten rocks.
3. The main channel through which magma moves towards the surface is the central vent.
4. A crater is at the top of a volcano and it is from here that much of the lava, gas, rock fragments and ash are ejected.
5. Volcanic cones are the result of eruptions which are mostly small pieces of rocks that build up cones around the vent.

Q.7. How are Fold Mountains formed?

Ans. Process of Fold Mountain Formation is as follows- 

• Fold mountains are generally formed in the less deformed areas adjacent to areas strongly affected by thrust tectonics.
• Typically, they are found in the foreland region where a major mechanically weak horizon is present.
• The frontal thrust (or thrusts) propagate(s) a long distance along the horizon and subsequent movement on the thrust can give rise to a sequence of folds as the hanging wall of the thrust effectively crumples.
• The anticline crests may be high enough to form mountains.
• Most of the fold mountains are likely to be relatively young in geological terms as they will start eroding as soon as they are formed.

Q.8. How are Block Mountains formed?

Ans.Process of Block Mountain Formation is as follows 

• Block Mountains are formed when large areas of bedrock are widely broken up by faults creating large vertical displacements of continental crust.
• Vertical motion of the resulting blocks, sometimes accompanied by tilting, can then

lead to high escarpments.

• These mountains are formed by the Earth’s crust being stretched and extended by
• tensional forces.
• Fault block mountains commonly accompany rifting, another indicator of tensional tectonic forces.
• The uplifted blocks are called block mountains or Horsts. The intervening dropped blocks are termed as graben.
• These can be small and form extensive rift valley systems. This form of landscape can be seen in East Africa, the Vosges, the Basin and Range province of Western North America, in South-Central New England and the Rhine Valley.
• Volcanic eruptions often occur when the regional stress is extensional and the crust is thinned.

Q. 9. Write a note on Lava Plateau.

Ans. 

• Lava plateaus are formed by highly fluid (runny) basaltic lava during numerous successive eruptions through numerous vents without violent explosions (quiet eruptions).
• These eruptions are quiet because of low viscosity of lava and contain small amounts of trapped gasses.
• Multiple successive and extensive lava flows cover the original landscape to eventually form a plateau, which may contain lava fields, cinder cones, shield volcanoes and other volcanic landforms.

Also Check – Major Landforms of The Earth Class 6th – Notes

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