Geomorphic Processes Short and Long Important Question Class 11 Geography Chapter-5 Book-Fundamental of Physical Geography

 

 

Q. What is weathering? How do weathering activities work?

Answer - 

• Weathering is the process in which rocks are broken down and disintegrated by external agents

• Such as: wind, rain, temperature, micro-organisms, animals, etc.

• Weathering is defined as the disintegration and decomposition of materials through the actions of various elements of weather and climate

Q.  How do weathering activities work?

Answer -

1. Chemical

2. Physical or mechanical

3. Biological weathering processes

Question –  What is physical weathering?

Answer - 

• Due to physical weathering, rocks break down into smaller pieces which require

• Factors such as gravitational force, changes in temperature, alternation of dry and humid conditions are responsible.

Question -  What is chemical weathering? How many types of weathering does it occur? 

Answer - 

• Chemical weathering is the process by which rocks and minerals are chemically broken down or changed.

Types of Chemical Weathering

1. Solution

• Many types of minerals present in rocks, such as nitrate, sulphate and potassium, dissolve in water and thus in areas with high rainfall and humid climate, rocks containing such minerals get weathered.

2. Carbonation

• Carbon dioxide dissolved in rainwater produces organic acid. This acid dissolves limestone-containing rocks, causing their weathering.

3. Hydration

• Some rocks, such as calcium sulphate, absorb water, expand and become weak, and then break down.

4. Oxidation

• Rusting of iron is a good example of oxidation. This process occurs when rocks come in contact with oxygen gas and this process takes place due to the mixing of atmosphere and oxygenated water.

Question:   How are biological activities helpful in soil formation?

Answer - 

• New surfaces are created by weathering caused by biological activities.

• Insects like ants, termites, earthworms, rodents etc. are of great importance in soil formation.

• They keep moving the soil up and down again and again.

• Earthworms help in forming soil chemicals.

• Due to burrowing by these organisms, changes occur in the soil surface as well. Dead plants and roots provide organic matter (humus) to the soil.

• In which bacteria start their work.

Question:  What are the main factors helpful in soil formation?

Answer -

1. Parent Material

• The base rock or deposit of soil formation.

• Local rock: Soil made from weathered rock

• Transported deposits: Soil brought from an outside source.

2. Topography

• The slope and shape of the site affect the depth and development of the soil.

• Steep slope: thin soil.

• Flat area: Deep and thick soil.

3. Climate

• Chemical and biological processes vary according to climate.

• Cold climate: more humus, slower bacterial growth.

• Hot climate: Organic matter oxidised quickly, less humus.

4. Biological Activity

• Plants and animals: Add organic matter, nitrogen and moisture.

• Humus: Plant remains that increase soil fertility.

• Insects: Change the structure of the soil.

5. Time

• Soil matures over time.

• New soil is considered young, while old soil is considered mature.

Question:  What are the reasons behind the deformation of the septum?

Answer - 

• Plate deformation includes all the processes that move, uplift and create the earth's crust. 

• Orogenic processes that build mountains through sharp folds

• continental processes involved in the uplift or deformation of large portions of the earth's surface

1. Earthquake

2. Plate tectonics.

Question -  Which factors activate the process of mass circulation?

Answer -

• Removal of the basis on which substances are sustained.

• Gradient of slopes

• Extreme rainfall

• earthquake

• Explosions or vibrations of machinery

• Excessive natural leakage

• Large amounts of water being drained from lakes, reservoirs and rivers

Question -  What is the importance of weathering?

Answer -

• Importance of weathering: Rocks break down into smaller pieces and help form soil. 

• Weathering helps in concentrating valuable minerals like iron, manganese, copper, etc. in rocks because due to weathering other substances get leached out and transferred and the minerals get collected at one place.

Question -  "Volcanism is a part of endogenous processes." Explain.

Answer - 

• The ejection of molten rock or other materials from below, in the form of lava and gases, from a crack or hole in the Earth's uppermost surface is called volcanism.

• The process includes both the lava coming up and solidifying there.

• Volcanism affects the structure and surface of the earth's crust. Thus volcanism is a part of internal forces.