ICSE Solutions for Class 7 geography

ICSE Solutions for Class 7 Geography Voyage – Major Industries

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 7 with Free PDF download option. Geography Voyage for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Discuss

Why do you think industries do not always employ adequate and right methods to control industrial pollution?
Answer:
Industries do not always employ adequate and right methods to control industrial pollution because the techniques to control industrial pollution are highly expensive. Industrialist’s feel huge burden on their pockets. Most of the Industrialist are uneducated, so they are not aware about how and why to control pollution.

VALUES AND LIFE SKILLS

Industries cause pollution when the factories that manufacture goods dump their wastes into water, air and soil.
Imagine that you are a factory owner. Write down a few ways in which you can reduce the pollution caused by your factory.
Answer:
I would followthe following steps

1. For the mitigation of smoke emissions from the chimney a stack should be installed at the emitting point.
2. Liquid coming out from the process of manufacturing should be treated in treatment plant before its disposal as civic waste water.
3. Solid waste of factory should be disposed off in safe way by throwing it into the designated landfill site.
4. For minimum emissions from chimney or up to the allowable
   limits, chimney is made according to scientific prescriptions so that whatever emits from it during or after the manufacturing process must be within its limited level.
5. Moreover, the quality of machinery and equipment which is used for manufacturing should also be well-maintained and its regular maintenance and repair should be done to help them limit the emissions from production.

EXERCISES

A. Fill in the blanks.

1. Steel is necessary material for making machines.
2. Jamshedpur and Rourkela are important steel producing centres in India.
3. Southern USA is an important cotton producing belt in the US.
4. Bengaluru is a major centre of information technology industry in India.
5. China is the world’s largest shipbuilding country.

B. Match the following.

Answer:

C. State whether the following is true or false.

1. Other industries depend on the steel industry for infrastructural material.
Answer. True.

2. Steel industry is set up in areas where raw materials are available.
Answer. True.

3. The Deccan Plateau is a major cotton producing region.
Answer. True.

4. Ethanol can be produced from cotton.
Answer. False.
Correct : Ethanol can be produced from sugar.

5. Practising the principle of 3 Rs can help in controlling pollution.
Ans. True.

D. Answer the following questions in brief.

Question 1.
Why is the steel industry considered the basic industry on which other industries depend?
Answer:
Steel is the necessary raw material for making machines as well as other infrastructural material for other industries. The iron and steel industry is the basic industry on which other industries are dependent.
Steel industry is dependent on raw materials such as iron ore, limestone, manganese and coal. Since these are heavy and bulky, this industry is usually located in the vicinity of the areas where these raw materials are available.

Question 2.
Why are cotton textile centres located in the Deccan Plateau?
Answer:
Cotton textile centres located in the Deccan Plateau due to following reasons:

1. Thick dark soil obtained which is suitable for growth of cotton and large production of cotton.
2. Abundant and cheap labour.

Question 3.
Name the factors that have made Bengaluru a major IT centre.
Answer:
Bengaluru has become a major IT centre because of its pleasant climate, good transportation facilities, highly trained professionals and progressive government policies.

Question 4.
Which are the major automobile-producing countries in the world?
Answer:
The top five car producing countries in the world that manufacture the most cars in the world are China, USA, Japan, Germany and South Korea.

Question 5.
What are the major causes of industrial pollution?
Answer:
The major causes of industrial pollution are:

(a) Toxic chemicals used by industries in processing and manufacturing.
(b) Consumer products such as paints, sprays, plastics, cement, electronic parts, petroleum cleaning solvents, etc.
(c) Numerous industrial chemicals used in the manufacture of various products such as leather goods, paints, medicines, hospital wastes, etc.
(d) Greenhouse gas emissions such as CO.
(e) Activities such as mining, cutting down forests, construction of huge buildings, dams, highways etc.

E. Answer the following questions in one or two paragraphs.

Question 1.
Give an account of the cotton textile industry in India.
Answer:
The cotton textile industry is one of the primary industries in India. More than 40 per cent of the working population of India directly or indirectly depends on this industry.
The manufacturing of cotton textile involves the following
processes:

1. washing of fibres
2. carding and combing of fibres to form a rope-like mass of fibres known as‘slivers’
3. spinning to make cotton yam
4. weaving of the ‘ grey cloth’ or undyed cloth
5. bleaching of the ‘grey cloth’
6. dyeing and printing

Question 2.
Write a note on sugar producing countries.
Answer:
In 2015, the top five sugar cane producing countries of the world were Brazil, India, China, Thailand and Pakistan. In Brazil, the heart of sugar cane area is located in the south-central part of the country. In India, sugar cane is produced mainly in Uttar Pradesh, Maharashtra and Karnataka.

Question 3.
What do you know about the ship-building industry in the world ?
Answer:
Shipbuilding is the world’s oldest industry. China is the world’s largest shipbuilder, followed by Japan and South Korea. In China, the shipbuilding industry is around Beijing, one of the world’s largest shipbuilding centres.

F. Trace your journey: Imagine you are a cotton boll. Write about your journey from the field to somebody’s wardrobe write about all the stages you had to pass through to become a garment.
Answer:
Here are the following stages we had to pass through to become a garment:

1. washing of fibres
2. carding and combing of fibres to form a rope-like mass of fibres known as ‘slivers’
3. spinning to make cotton yam
4. weaving of the ‘grey cloth’ or undyed cloth
5. bleaching of the‘grey cloth’
6. dyeing and printing

G Map work.

Question 1.
On an outline map of the world mark any five major industrial centres of the world.
Answer:
Five major industrial centres of the world are :

1. Sydney
2. Chicago
3. Berlin
4. London
5. St. Petersburg

Question 2.
Mark two major centres of IT industries.
Answer:
Bengaluru and Silicon Valley

Question 3.
Mark two major centres of steel production.
Answer:
Singhbhum and Raniganj.

H. Picture Study

Question 1.
This picture shows an industry that cannot be set up in all areas. Why ?
Answer:
This is a steel industry which cannot be set up in all areas because raw materials and cheap labour are not easily available.

Question 2.
Name the raw materials used in this industry.
Answer:
Iron ore, limestone, manganese and coal.

Let’s Do Something
Take some time out to visit a handicrafts shop nearby. Make a note of the following there :

1. What are the items sold in the shop ?
2. How are these products manufactured ?
3. Where have they come from ?

Answer:
Do it Yourself.

ICSE Solutions for Class 7 Geography Voyage – Industries : Their Need and Classification

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 7 with Free PDF download option. Geography Voyage for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Discuss

Discuss the importance of cottage industry for a country which has a large population with little education.
Answer:
A major benefit of cottage industries is that they allow people to work from their homes. Women have benefited the most because they can work from home while still tending to their families. Many cottage businesses include the entire family in their operations, however, including husbands and children. Some businesses start as cottage industries and then become too large, necessitating a move out of the home into a business environment, but at that point they likely have the financial means to make the move.

Discuss

What, according to you, would be the future of industries if we destroyed our forests and wildlife ?
Answer:
Forest-based Industries are based on forest products. If we destroys forest the industries such packaging industry, furniture industry, sports good industry, paper industry are shutdown because of unavailability of raw materials.

THINK AND ANSWER

Why do you think multinational companies are attracted to establish ventures in foreign countries ?
Answer:
Multinational companies are attracted to establish ventures in foreign countries as cheap labour and cheap raw material inputs, transport and power are easily available in developing countries.

VALUES & LIFE SKILLS

A lot of children below the age of 14 years work in various industries.
Do you think these children should work in these industries ?
Why do you think they have to work there ?
Answer:
Child labour is the employment of children at regular and sustained labour.
No, the children should not work in any industry because of following reasons:

1. Child labour does more than deprive children of their education and mental and physical development – their childhood is stolen.
2. Immature and inexperienced child labourers may be completely unaware of the short and long term risks involved in their work.
3. Working long hours, child labourers are often denied a basic school education, normal social interaction, personal development and emotional support from their family.
   Poverty is undoubtedly a dominant factor in the use of child labour; families on or below the poverty line force their children into work to supplement their household’s meager income. Eradicating poverty, however, is only the first step on the road to eliminating child labour.

EXERCISES

A. Fill in the blanks.

1. People who work together to make cars work in the large- scale industry.
2. The USA and China are strong because they have thousands of industries.
3. Nepal has few industries.
4. The size of an industry depends on the number of people employed, the capital invested and the area it occupies.
5. A cottage industry is a household unit run by a family.

B. Match the following.

Answer:

C. Choose the correct answer.

Question 1.
China/Nepal has many industries.
Answer:
China has many industries.

Question 2.
Cottage industries produce handicrafts/cement.
Answer:
Cottage industries produce handicrafts.

Question 3.
Small-scale industries are smaller/bigger than cottage industries.
Answer:
Small-scale industries are bigger than cottage industries.

Question 4.
Sports equipment are produced by small-scale/large- scale industry.
Answer:
Sports equipment are produced by small-scale industry.

Question 5.
Chota Nagpur Plateau is well known for steel/textile production.
Answer:
Chota Nagpur Plateau is well known for steel production.

D. State whether the following is true or false.

1. The USA has many industries.
Answer. True.

2. Industries do not contribute much to national income.
Answer. False.
Correct : Industries contribute much to national income.

3. The number of labour employed has no relation to the size of an industry.
Answer. False.
Correct : The number of labour employed has relation to the size of an industry.

4. Cottage industry employ labour from outside.
Answer. False.
Correct : Cottage industry employ only family members.

5. Small-scale industries employ only family members.
Answer. False.
Correct : Small-scale industries employ labour from outside.

E. Answer the following questions in brief.

Question 1.
What is an industry?
Answer:
An Industry is a group of people or companies engaged in a particular kind of business enterprise. There are different groups of people that work together to form an industry. For example, people who work together to make cars form the car industry or people who work together to fashion clothes form the fashion industry.

Question 2.
Name the three major types of industries.
Answer:
Three types of industries are :

1. Cottage industry
2. Small-scale industry
3. Large-scale industry.
4. Agro-based industry.

Question 3.
What goods are produced by a cottage industry?
Answer:
Handicrafts, handloom products, jewellery, pottery, leather products, etc. are produced by cottage industry.

Question 4.
Name a few goods produced by small-scale industries.
Answer:
Electronic goods, sports equipment, brassware, bicycles, toys,
etc. are produced by small-scale industries.

Question 5.
Which type of industry produces cement and petrochemicals?
Answer:
Cement and petrochemicals are produced by large-scale industry.

F. Answer the following questions in detail.

Question 1.
Why do we need industries?
Answer:
Industries are required because of the following reasons :

1. Industries are needed to make a country strong financially: The more number of industries in a country the stronger the country becomes. Countries such as the USA and China are strong because of the hundreds and thousands of industries they have. India too has many industries but not as many as USA or China. Some countries like Nepal have very few industries.
2. Industries are needed for products of daily use : We will see items that we use everyday such as toothpaste, soap, bicycle, exercise books, pencils, medicines, cheese, and jams and so on. All these items are manufactured by different industries.
3. Industries are needed so there is no shortage of necessary goods :
   Apart from fulfilling our daily needs, industries must produce
   sufficiently so that all the things people need are available to them at reasonable prices.

Question 2.
What is a cottage industry?
Answer:
Cottage Industry : It is generally a household unit run by a family.
The craftsmen and their family members carry on the traditional work started by their forefathers generations ago. Cottage industries generally produce all kinds of handicrafts, handloom products, jewellery, pottery, leather products, etc. These industries are encouraged by the government as they generate employment and improve living conditions, especially in rural areas.

Question 3.
What are the differences between a cottage industry and a small-scale industry?
Answer:
The differences between a cottage industry and a smale- scale industry are:

1. The location of cottage industries is restricted in villages whereas the small-scale industries are mostly located in urban and semi- urban areas.
2. Cottage industry being a household industry is mostly run by the members of the family and therefore do not maintain hired labourers. But the small-scale industries are mostly run by hired labourers.
3. Cottage industries are producing goods for meeting local requirements whereas small-scale industries are producing goods to meet the demand for the people living in a wider area.
4. Cottage industries are investing a very little amount of capital and are working with simple tools. But the small industries are investing a comparatively higher amount of capital (presently the limit has been raised from Rs. 60 lakh to Rs. 3 crore) and are working with machines run by power.

Question 4.
What are large-scale industries?
Answer:
Large-scale industries involve huge investments, professional management and a large force of skilled and unskilled labour.
Big power-driven machines are used with considerable automation. These industries are generally established at places where raw materials, cheap transportation, sources of power, plenty of labour and market are easily available. Industries producing iron and steel, petrochemicals, cement, railway engines and coaches, automobiles, textiles, etc. are examples of large-scale industries.

Question 5.
Give an account of the factors that determine the establishment of an industry.
Answer:
Factors that determines the establishment of an Industry are:

1. Availability of Raw Material — All industries that require heavy and bulky raw material are generally set up near the sources of raw materials in order to save heavy transportation cost. For example, iron and steel plants in India and other countries have been set up near iron ore mines and coalfields as both iron ore and coal are heavy and difficult to transport.
2. Availability of Power — For any industry power is a very critical factor. Cheap, abundant and uninterrupted power supply is an essential need for any modem industry using large machines.
3. Availability of Transport —An important factor for setting up industries is the availability of efficient means of transportation as movement of raw material to the factory and finished goods to the market depend on it.
4. Availability of Labour — Though labour-skilled and unskilled-can be transported from different regions, it is advantageous to have an assured labour supply locally for setting up an industry.
5. Market — The ultimate aim of any industry is to sell its product easily, i.e., to find a market for its product without much difficulty. Industries of certain types are set up in specific regions where their goods can easily be sold. Woollen industries will do well in areas of cold climate while industries making cotton goods will

LET’S DO SOMETHING

With the help of the Internet, find out the names of three companies from the following industries :

1. Iron and steel
2. Textile
3. Cement

Answer:

1. Tata Iron and Steel Corp., Bhilai Steel Plant, Durgapur Steel Plant.
2. Acrow India ltd., Al chemist corp. ltd. Acil Cotton Industries ltd.
3. Ultratech,ACC,Ambuja Cement, Ramco Cements. thrive in areas that have warm and dry climate.
4. Other Factors — Factors like easy access to financial and banking facilities, climate, state-government policies, etc. also influence either directly or indirectly the location of an industry.

G. Ask your parents to take you to a cottage or small-scale industry in your city so that you can see how goods are produced there ?
Answer:
Do yourself with the help of parents.

H. Picture Study
This is a picture of an industry.

1. What type of industry is this ?
2. Can you give two features of this industry?

Answer:

1. This is a large-scale industry of automobiles sector.
2. Large-scale industries involve huge investments, professional management and a large force of skilled and unskilled labour. Big power-driven machines are used with considerable automation. These industries are generally established at places where raw materials, cheap transportation, sources of power, plenty of labour and market are easily available.

LET’S DO SOMETHING

With the help of the Internet, find out the names of three companies from the following industries:

1. Iron and steel
2. Textile
3. Cement

Answer:

1. Tata Iron and Steel Corp., Bhilai Steel Plant, Durgapur Steel Plant.
2. Acrow India ltd., A1 chemist corp. ltd. Acil Cotton Industries ltd.
3. Ultratech, ACC, Ambuja Cement, Ramco Cements.

 

 

ICSE Solutions for Class 7 Geography Voyage – Australia: Climate, Natural Vegetation, Wildlife; Forest and Minerals

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DISCUSS

Discuss the roie of the Eastern Highlands in the climate of Australia.
Answer:
Eastern Highlands block the rain-bearing winds ; as a result, most of Western Australia is a desert.

THINK AND ANSWER

Why do we not find marsupials like kangaroo and wombat in other parts of the world ?
Answer:
Marsupials like kangaroo and wombat are not found because the continent separated from the main land mass about 200 million years ago. As a result, its animal life evolved quite differently from that of the rest of the world.

EXERCISES

A. Match the columns

Answer:

B. Identify who I am.

Question 1.
i am an animal that lives entirely on the juicy leaves of the gum tree.
Answer:
Koala

Question 2.
I am a wild dog found in Australia.
Answer:
Dingo

Question 3.
I am a mammal that lays eggs.
Answer:
Platypus

Question 4.
I am a big Australian bird but I cannot fly.
Answer:
Emu

Question 5.
I have a beautiful fan-tail and I can mimic very well.
Answer:
Cassowary

Question 6.
I am a male bird who likes to attract female birds by building intricate and decorative nests.
Answer:
Bower

Question 7.
I am popularly called the ‘laughing jackass’.
Answer:
Kookaburra

C. Answer the following questions in brief.

Question 1.
Name the winds that bring rainfall to Australia.
Answer:
The South-East Trade Winds blow onshore and bring heavy rainfall to the east coast. The Westerlies bring rainfall in winter to south-west and south-east Australia. The north-west monsoon winds cause rainfall over northern Australia.

Question 2.
What is the name of the temperate grassland in Australia?
Answer:
The temperate grasslands of Australia are called the downs.

Question 3.
What kind of natural vegetation can be seen in the desert regions of Australia ?
Answer:
Natural vegetation in the desert are cactus, spinifex, and acacia (locally called wattle).

Question 4.
Why is the wildlife of Australia considered unique in comparison to other countries ?
Answer:
The wildlife of Australia is unique. The continent separated from the main land mass about 200 million years ago. As a result, its animal life evolved quite differently from that of the rest of the world.
Among the unique animals found here are marsupials are— mammals that carry their young ones in a pouch formed by a fold of skin near the stomach. The pouches contain the mammary glands.

Question 5.
The platypus is considered a strange animal. Why ?
Answer:
The platypus is considered a strange animal because they lay eggs but suckle their young ones. The platypus is an aquatic, furred mammal with a bill like that of a duck and poisonous spurs on its hindlegs.

D. Answer the following questions in one or two paragraphs.

Question 1.
Name the factors that influence the climate of Australia. Elaborate any two.
Answer:
The factors that influence the climate of Australia are its location, land features, direction of mountain ranges, winds and distance from the sea.

Location — The northern part lies in the tropics, so it is either warm or hot all the year round. The rest of the continent lies south of the Tropic of Capricorn and, as a result, has warm summers and mild or cool winters.
Land Features — The east coast gets heavy rainfall from the South-east Trade Winds, which steadily decreases westward, owing to the presence of the Eastern Highlands that form a barrier for the rain-bearing winds.
Direction ofMountain Ranges — If the Great Dividing Range did not lie in a north-south direction, Western Australia would not have been a desert.
Winds — The South-East Trade Winds blow onshore and bring heavy rainfall to the east coast. The Westerlies bring rainfall in winter to south-west and south-east Australia. The north-west monsoon winds cause rainfall over northern Australia.

Question 2.
The Western Plateau region of Australia is mainly a desert. Why ?
Answer:
The presence of the Eastern Highlands causes heavy rains along the eastern coast and rainfall decreases westwards, away from the coast. So, most of central and western Australia has high temperatures and very little rainfall resulting in the formation of a desert.

Question 3.
Briefly describe the climate and vegetation of the south-eastern and south-western coasts of Australia.
Answer:
The presence of the Eastern Highlands causes heavy rains along the eastern coast and rainfall decreases westwards, away from the coast. So, most of central and western Australia has high temperatures and very little rainfall resulting in the formation of a desert.
South-eastern and south-western parts which experience rain in winter from the onshore Westerlies. Winter condition prevail from April to September in this reason.
The temperate forests are found in the south-eastern and south¬western parts of Australia and in Tasmania. Eucalyptus (locally called eucalypt or gum tree) is the main tree of these forests. There are over 900 species of eucalyptus tree found in Australia. This tree does not shed its leaves, but the bark peels off and is replaced by new white or light coloured bark. Eucalyptus trees dominate the landscape of Australia.

Question 4.
What are marsupials ? Describe any one marsupial.
Answer:
Marsupials are — mammals that carry their young ones in a pouch formed by a fold of skin near the stomach. The pouches contain the mammary glands. Australia has about 150 species of marsupials that vary in size, from the giant kangaroo over two metres in height to the tiny insect-eating bandicoot. The wallaby, wombat, and koala are other examples of marsupials found in Australia.

Question 5.
What are monotremes ? Give examples.
Answer:
The platypus and echidna are the only living monotremes, i.e., they lay eggs but suckle their young ones. The platypus is an aquatic, furred mammal with a bill like that of a duck and poisonous spurs on its hindlegs.The echidna is also known as the spiny anteater.

E. Map work
Study the map given here and answer the questions (lines indicate the different climatic regions) : (On Textbook page 149)

Question 1.
Describe the vegetation of region C.
Answer:
Temperate Grassland

Question 2.
What are the most outsanding characteristics of the climate of region B ?
Answer:
Tropical Monsoon

Question 3.
On the map, draw the South-East Trade Winds with red
Answer:
arrows.

Question 4.
By what name are the temperate grasslands known in the Murray-Darling Basin ?
Write the name in the appropriate place on the map.
Answer:
The temperate grasslands of Australia are called the downs.

F. Picture study
This is a photograph of an eucalyptus tree, a common tree found in Australia. There are over 900 species of this tree in Australia.

Question 1.
What is the local name of this tree?
Answer:
Eucalypt

Question 2.
Which animal survivies by eating the leaves of this tree?
Answer:
The koala is the most popular Australian animal. This tree dweller is only about 76 cm high and lives entirely on the sjuicy leaves of the eucalyptus tree.

ICSE Solutions for Class 7 Geography Voyage – Weathering and Soil

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 7 with Free PDF download option. Geography Voyage for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

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Discuss

From encycopaedias and the Internet, find out the different types of soil found in India. Discuss the importance of these soils for crops cultivated in our country. You should form groups in class for this activity.
Answer:
Soils of India: Six Different Types of Soils Found in India are as follows:
Soil is our prime natural and economic resource. Soils in India differ in composition and structure.

1. Alluvial Soils : These are formed by the deposition of sediments by rivers. They are rich in humus and very fertile. They are found in Great Northern plain, lower valleys of Narmada and Tapti and Northern Gujarat. These soils are renewed every year.
2. Black Soils : These soils are made up of volcanic rocks and lava-flow. It is concentrated over Deccan Lava Tract which includes parts of Maharashtra, Chhattisgarh, Madhya Pradesh, Gujarat, Andhra Pradesh and Tamil Nadu. It consists of Lime, Iron, Magnesium and also Potash but lacks in Phosphorus, Nitrogen and Organic matter.
3. Red Soils : These are derived from weathering of ancient metamorphic rocks of Deccan Plateau. Its redness is due to iron composition. When iron content is lower it is yellow or brown. They cover almost the whole of Tamil Nadu, Andhra Pradesh, Chhattisgarh, Karnataka, Maharashtra and parts of Orissa.
4. Laterite Soils : These soils are formed due to in-tense leaching and are well developed on the sum-mits of hills and uplands.
   They are commonly found in Kerala, Tamil Nadu, Maharashtra, Chhattisgarh and hilly areas of Orissa and Assam.
5. Mountain Soils : These soils are formed as a result of the accumulation of organic matter derived from forest growth. They are found in Himalayan region and vary in different regions according to altitude. Tea is grown in those areas which receive sufficient rainfall.
6. Desert Soils : In the desert regions of Rajasthan, soils are not well developed. As evaporation is in excess of rainfall, the soil has a high salt content and saline layer forms a hard crust. These soils are gen-erally sandy and deficient in organic matter.

THINK AND ANSWER

Soil formation is an important benefit of weathering. How is it important for mankind ?
Answer:
Soil formation is an important for mankindas :

1. A habitat for several plants and animals
2. A storage bank for water and nutrients
3. Foundation of the world’s food chain
4. Provides an anchor for plants

VALUES AND LIFE SKILLS

People have used various farming methods to increase food production. However, in the process, they have stripped soil of nutrients, leading to its degradation.
Can you suggest some ways by which we can reduce soil degradation ?
Answer:
We can reduce soil degradation by Contour tilling, terrace farming, strip cropping, contour bunding, afforestation, crop rotation, fallowing and controlled grazing.

EXERCISES

A. Match the column

Answer:

B. Distinguish between each of the following pairs

Question 1.
Degradation and aggradation
Answer:
Degradation :
The process by which rock materials from the earth’s surface are removed resulting in general lowering of land surfaces.
Aggradation :
The process by which the rock material removed from the earth’s surface and then deposited in depressions such as valleys, lakes and sea beds. The depression fills

Question 2.
Weathering and erosion
Answer:
Weathering :
It is the process by which rocks on the land surface break down or crumble because of the action of the elements of weather such as rain, frost and temperature changes.
Erosion :
It is the process by which the weathered materials are transported elsewhere by agents such as running water, moving ice waves, and winds.

Question 3.
Granular disintegration and exfoliation
Answer:
Granular disintegration :
A form of weathering where the grains of a rock become loosened and fall out to leave a pitted and uneven surface.
Exfoliation :
When the surface layers of rounded and boulders gradually peel off in layers due to expansion of the outer layer during the day and the contraction of the same layer during night, the process is called exfoliation.

Question 4.
Hydration and solution
Answer:
Hydration :
This occurs when water itself chemically combines with some minerals present in rocks. Thus, crystalline minerals, such as feldspar and potash, absorb water and become a powdery mass due to the process of hydration, resulting in their erosion.
Solution :
This is the simplest form of chemical weathering by which some minerals dissolve in water when rainwater falls on rocks or when river water flows over rocks. The soluble minerals dissolve and are removed, . resulting in the breakup of the rocks.

Question 5.
Soil erosion and soil conservation
Answer:
Soil erosion :
It refers to the washing away or removal of the layers of soil by various agents like running water and wind.
Soil conservation :
It refers to the protection of soil against erosion and exhaustion because of deforestation, excessive grazing, running

C. Give geographical reasons

Question 1.
Temperature changes result in physical weathering.
Answer:
Temperature changes result in expansion and contraction of rocks during day and night resulting in degradation of rocks. In the temperate latitudes the frost shatters the rocks.

Question 2.
Gases in the atmosphere affect weathering.
Answer:
The minerals contained in the rocks react with the gases and moisture in the air like oxygen reacts with iron and causes the rocks to rust and get eroded.

Question 3.
Human activities affect weathering.
Answer:
Human activities like mining, quarrying deforestation, tunnelling, road construction and farming affect the weathering.

Question 4.
Soil is a very important resource.
Answer:
Soil is an important resource as human beings depend on it for their basic needs of food, shelter and clothing. It takes thousands of years for a thin layer of soil to form.

Question 5.
There is a need for soil conservation.
Answer:
Soil should be conserved as humans depend directly or indirectly on soil for their basic needs of food, shelter and clothing.

D. Answer the following questions in brief

Question 1.
Name any four agents of erosion.
Answer:
Soil erosion also refers to the loss of fertility of soil, which makes the soil infertile and exhausted. Cutting down of trees and forests, overgrazing by animals, floods, and improper farming practices are some of the main causes of soil erosion.

Question 2.
List any three factors that affect weathering.
Answer:
Factors that affect weathering are :

1. Local climate
2. Mineral composition
3. Structure of rock
4. Human activities
5. Amount of exposed or bare rocks surface, and human activities.

Question 3.
In which regions of the world is ‘frost action’ the common form of weathering?
Answer:
In temperate latitudes frost action is common form of weathering.

Question 4.
Which is the most important effect of weathering?
Answer:
Landslides and soil erosion are two major effects of weathering.

Question 5.
What are the components of topsoil?
Answer:
The topmost layer is the topsoil (Layer D) which consists of clay, silt, sand and humus.

Question 6.
Name the various methods of conserving soil.
Answer:
The various methods of conserving soil are :
Contour tilling, terrace farming, strip cropping, contour bunding, afforestation, crop rotation, fallowing and controlled grazing.

Question 7.
Distinguish between contour tilling and contour bunding.
Answer:
Contour Tilling — In this method the farmer tills or ploughs
the fields along the contours of the land rather than tilling up and down the slope. Contour tilling is practised in hilly areas rather than the plains. It prevents the soil from being washed away by water or by surface run-off as the contour acts like a bund. The contour also facilitates the percolation of water into the soil.
Contour Bunding — Soil is conserved by making bunds or walls or embankments made of mud along contour lines to prevent water from draining out of the cultivated field, thereby preventing erosion.

Question 8.
What do you understand by controlled grazing ?
Answer:
Controlled grazing is a simple method of soil conservation, It is to restrict the grazing of cattle, sheep and goats on grasslands and within forests. When cattle graze on fields, grass and smaller plants get tom from their roots, leaving the soil loose and exposed to wind and water erosion. Moreover, the pressure of the animals hooves on the soil makes it lose its cohesion and structure, exposing it to the forces of wind and water. Land meant for grazing of cattle should be specially selected and fenced off.

E. Answer the following questions in one or two paragraphs

Question 1.
What is gradation? Describe the two processes involved in gradation.
Answer:
Gradation is the process of levelling the land by means of moving agents like rivers, or wearing away and lowlands are raised by adding the eroded material by the process of deposition. This is because there is constant earth movement which raises mountains and winds, seas and waves. The highlands are made low by erosion and this process is called degradation and materials are deposited elsewhere in depressions like valleys, lakes, etc. and these lowlands are raised by the process called aggradation.

Question 2.
Describe the process that leads to exfoliation.
Answer:
When the surface layers of rounded rocks and boulders gradually peel off in layers is called exfoliation. This occurs due to expansion of the outer layer during the day and the contraction of the same layer during the night, repeatedly over a period of time.

Question 3.
Discuss the role of water in the process of chemical weathering.
Answer:
Water plays an important role in chemical weathering. The carbon dioxide in atmosphere dissolves in rainwater and form carbonic acid and reacts with minerals in the rocks. The soluble minerals dissolve in water such as feedspar and potash absorb water and become a powdery mass. Similarily soluble minerals dissolve and are removed, resulting in the breakup of the rocks. Rock salt, gypsum, and silica are examples of minerals that are highly soluble and when rainfall falls they decompose.

Question 4.
How do animals and plants assist in weathering?
Answer:
The decaying remains of dead plants in soil tend to form organic acid which when dissolved in water cause chemical weathering. Ants, earthworms and burrowing animals such as rats and rabbits loosen soil and make tunnels causing weathering.

Question 5.
What is meant by the terms ‘soil erosion’ and ‘soil conservation’?
Answer:
Soil erosion refers to washing away or removal of the layer of soil by various agents like running water and wind.
Sheet erosion and gully erosion are the two most common ways by which soil gets eroded. When there is heavy rainfall, the top layer of soil over large areas gets washed away. This is known as sheet erosion. When rainwater in region flows down the slopes making deep and narrow furrows, it is called gully erosion. Soil erosion also refers to the loss of fertility of soil, which makes the soil infertile and exhausted.
Cutting down the trees and forests, overgrazing by animals, floods, and improper farming practices are some of the main causes of soil erosion.
Soil conservation is the protecting of soil against erosion and exhaustion by planting trees, shrubs and grass on hill slopes.
Soil can be conserved by controlling grazing of cattle and use of proper farming methods such as the levelling of fields, terracing of hill slopes, construction of mud walls or bunds and ploughing fields in circles.

Question 6.
Why is soil conservation important ? Give three reasons.
Answer:
Soil conservation is very important because soil consists of
mineral particles, moisture, living organisms like bacteria and earthworms, and decayed organic matter. It is one of the most important resources as human beings-depend on it, both directly and indirectly, for their basic needs of food, shelter, and clothing. It takes thousands of years for even a thin layer of soil to form.

Question 7.
Explain any two methods of soil conservation briefly.
Answer:

1. Contour Tilling — In this method the farmer tills or ploughs
   the fields along the contours of the land rather than tilling up and down the slope. Contour tilling is practised in hilly areas rather than the plains. It prevents the soil from being washed away by water or by surface run-off as the contour acts like a bund. The contour also facilitates the percolation of water into the soil.
2. Terrace Farming — Terrace farming involves making terraces or steps on a hill or mountain by cutting into the side of the hill or mountain. Since the land is made flat, it reduces surface run-off, thereby preventing erosion. It also facilitates the absorption of water into the soil. Terrace cultivation is common on mountain slopes all over the world.
3. Contour Bunding — Soil is conserved by making bunds or walls or embankments made of mud along contour lines to prevent water from draining out of the cultivated field, thereby preventing erosion.

F. Make a chart for your classroom showing the causes of different types of weathering.
Answer:
Do it yourself.

G. Form pairs or groups of three or four students and discuss, with examples, how we depend directly and indirectly on soil.
Answer:
Do it Yourself with the help of teacher.

H. Picture Study

Question 1.
What is this farming method called ?
Answer:
Terrace farming.

Question 2.
Mention any two other methods that help in controlling soil erosion.
Answer:
Construction of mud walls, ploughing fields in circles, levelling of fields can also prevent soil erosion.

 

ICSE Solutions for Class 7 Geography Voyage – Australia:Location,Area, Political & Physical Features

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 7 with Free PDF download option. Geography Voyage for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

ICSE Solutions Class 7 Geography History & CivicsMathsPhysicsChemistryBiology

DISCUSS

Why are the Eastern Highlands called the Great Dividing Range ?
Answer:
The Eastern Highlands are also called the Great Dividing Range because the mountains form the main watershed of Australia. A number of Australia’s principal rivers originate here. The Snowy River flows down the steep eastern slope while the Darling, Lachlan, and Murrumbidgee Rivers flow down the western slope and join the Murray River.

THINK AND ANSWER

Why can’t Australia’s exotic flora and fauna be found anyw here else in the world ?
Answer:
Australia is a natural wonderland of beautiful beaches, crystal blue waters, amazing ancient rock formations and pristine rain forests. Australia is the sixth largest country in the world and has the lowest population density per square kilometer. Australia has 16 world heritage listed properties with its historic townships, bustling cities, vivid landscapes and exotic flora and fauna all adding to its unique appeal. Most of Australia’s exotic flora and fauna cannot be found anywhere else in the world and the lifestyle is one second to none.

EXERCISES

A. Fill in the blanks

Australia is located between latitudes 10°S and 40°S and , between longitudes 114°E and 154°E. So, this Island continent lies wholly in the Southern hemisphere. Australia is the sixth largest country in the world but is the smallest continent. The name Australia comes from the Latin word ‘Australis’ meaning Southern. The official name is the Commonwealth of Australia. Some other popular names are the ‘Land of Migrants’ and the ‘Island Continent’.

B. Choose the correct answer

1. The Great Dividing Range is so called because:

1. it divides Australia into two halves
2. it is very high
3. it acts as a watershed between the rivers flowing to the east and those flowing westwards

2. The Lake Eyre Basin is called an area of inland drainage because :

1. the area keeps changing
2. the rivers flowing in this area have no outlet to the sea
3. it is a low-lying lake

C. Answer the following questions in brief

Question 1.
Name the water bodies that surround Australia.
Answer:
Australia lies between the Indian Ocean in the west and the_ South Pacific Ocean in the east.

Question 2.
Identify and name the important line of latitude that passes through the middle of Australia.
Answer:
The tropic ofCapricom or 231/2 °S latitude passes through the middle of Australia.

Question 3.
Why are the Eastern Highlands also called the Great Dividing Range?
Answer:
The Eastern Highlands are called the Great dividing range because the mountains here form the main watershed of Australia. A number of Australia’s principal rivers originate here.

Question 4.
What is an ‘aquifer’?
Answer:
A porous layer of rock capable of storing water and allowing its passage is called aquifer.

Question 5.
What is meant by ‘inland drainage’? Give an example.
Answer:
Inland drainage is that drainage in which the rivers do not reach an ocean or sea and drain in a lake or an ‘inland’ sea, e.g. Lake Eyre.

Question 6.
Which breed of sheep is mainly reared in Australia ?
Answer:
The merino breed of sheep, which produces the best fleece for wool, is mainly reared in Australia.

Question 7.
Identify the four main sheep-rearing states of Australia.
Answer:
The main sheep-rearing states are New South Wales, Victoria, Western Australia, and South Australia.

D. Answer the following questions in one or two paragraphs

Question 1.
Mention two differences between the rivers that flow down the western and eastern slopes of the Great Dividing Range.
Answer:
The Great Dividing range in the east divides the flow of rivers in the region. The rivers that flow down the eastern slopes’ are short and perennial and drain into Pacific Ocean. The rivers that flow down the western slopes are longer and flow to central lowlands and have inland drainage.

Question 2.
Explain an artesian basin and an artesian well.
Answer:
Artersian basin is a layer of porous or pervious rock lies between two layers of impervious rocks and acts as a reservoir. The rain water seeps underground and the rock becomes capable of holding water and allowing it to pass through it called aquifer. A well is bored into the aquifer through which water rises to the surface by natural pressure is called artesian well.

Question 3.
Why is most of the underground water not suitable for human consumption agriculture?
Answer:
Most of the underground water is not suitable for irrigation and human consumption as the water is salty and is present in the artesian basin of Australia.

Question 4.
How are corals formed?
Answer:
Corals are a hard substance composed of skeleton of tiny marine creatures called coral polyps. When corals die their hard skeletons remain fixed in place. Since these polyps live in colonies, when they die their large accumulation of skeletons form coral reefs which are circular or ridge-like.

Question 5.
Write three interesting points about the Great Barrier Reef.
Answer:
Some Important points about the Great Barrier Reef are:

1. The Great Barrier Reef is a 2,300 km long underwater ridge-like feature off the north-east coast of Australia at distance varying from 16 to 240 km from the coastline.
2. It is composed of millions and millions of shells of tiny marine creatures called coral polyps.
3. The Great Barrier Reef is Australia’s biggest tourist attraction. The warm, shallow, salty sea between the reef and the shore is the home of tropical fish of bright colours, and crustaceans that abound in this underwater paradise.

E. Map work
On the outline map of Australia given here, neatly mark and label the following :

1. the capital cities of the states
2. The narrow stretch of water that separates Tasmania from Australia
3. The longest perennial river of Australia
4. The ocean that lies west of Australia
5. A ridge-like feature made up of coral
6. write SHEEP FARMING in an appropriate place on the map where it is practised.

Answer:

F. Picture Study

This is a photograph of Australia’s Great Barrier Reef. Why do you think this reef is Australia’s biggest tourist attraction.

Answer:
because its home for bright coloured tropical fishes and crustaceans that abound in this underwater paradise.

LET’S DO SOMETHING

Question 1.
On an outline map of Australia, mark the boundaries of South Wales-Victoria border different from the other borders ? Find out why.
Answer:
The boundaries of all the states except South-wales and Victoria border are same divided with a straight line.
The reason behind the border not being straight is that the majority of the border between Victoria and New South Wales is formed by the River Murray (Interestingly the river is actually in New South Wales entirely, instead of the border being right through the centre of the river). It doesn’t form the border between South Australia and Vic/NSW or any of the other states as it either doesn’t run through the states or, like in South Australia, cuts right through the initial territory designated for the free colony. As they didn’t want to form another state they just kept SA as it was and had the river running through it.
But essentially, the border is formed by the Murray, which, as a river, naturally isn’t a straight line.

Question 2.
Collect information about the Great Barrier Reef from encyclopaedias or the Internet and write a diary describing all you have learnt about it in your scrapbook.
Answer:
The Great Barrier Reef is one of the seven wonders of the natural world, and pulling away from it, and viewing it from a greater distance, you can understand why. It is larger than the Great Wall of China and the only living thing on earth visible from space.
Where Is The Great Barrier Reef ?
The marine park stretches over 3000km (1800 miles) almost parallel to the Queensland coast, from near the southern coastal town of Bundaberg, up past the northern tip of Cape York.
The reef, between 15 kilometres and 150 kilometres off shore and around 65 Km wide in some parts, is a gathering of brilliant, vivid coral providing divers with the most spectacular underwater experience imaginable.
A closer encounter with the Great Barrier Reefs impressive coral gardens reveals many astounding underwater attractions including the world’s largest collection of corals (in fact, more than 400 different kinds of coral), coral sponges, molluscs, rays, dolphins, over 1500 species of tropical fish, more than 200 types of birds, around 20 types of reptiles including sea turtles and giant clams over 120 years old.

What Is The Great Barrier Reef ?
The reef is a breeding area for humpback whales, migrating from the Antarctic and is also the habitat of a few endangered species including the Dugong (Sea Cow) and large Green Sea Turtle. In recognition of its significance, UNESCO listed the Great Barrier Reef as a World Heritage Site in 1981.
Because of its natural beauty, both below and above the water’s surface, the reef has become one of the worlds most sought after tourist destinations.
In 2006 there were approximately 820 operators and 1500 vessels and aircraft permitted to operate in the Great Barrier Reef Marine Park providing ease of access for all to experience the Great Barrier Reef and learn first hand about its natural delights and World Heritage values.
One of Australia’s most remarkable natural gifts, the Great Barrier Reef is blessed with the breathtaking beauty of the world’s largest coral reef. The reef contains an abundance of marine life and comprises of over 3000 individual reef systems and coral cays and literally hundreds of picturesque tropical islands with some of the worlds most beautiful sun-soaked, golden beaches.Because of its natural beauty, the Great Barrier Reef has become one of the worlds most sought after tourist destinations. A visitor to the Great Barrier Reef can enj oy many experiences including snorkelling, scuba diving, aircraft or helicopter tours, bare boats (self-sail), glass-bottomed boat viewing, semi-submersibles and educational trips, cruise ship tours, whale watching and swimming with dolphins.
A Natural Wonder :
The Great Barrier Reef is one of the seven wonders of the natural world, and pulling away from it, and viewing it from a greater distance, you can understand why. It is larger than the Great Wall of China and the only living thing on earth visible from space.

ICSE Solutions for Class 7 Geography Voyage – Types of Rocks

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APlusTopper.com provides step by step solutions for ICSE Solutions for Class 7 Geography Voyage. You can download the Voyage Geography ICSE Solutions for Class 7 with Free PDF download option. Geography Voyage for Class 7 ICSE Solutions all questions are solved and explained by expert teachers as per ICSE board guidelines.

ICSE Solutions Class 7 Geography History & CivicsMathsPhysicsChemistryBiology

THINK AND ANSWER

Why is diamond clear and hard while graphite is soft ? Why is coal hard and chunky ?
Answer:
Carbon atoms in diamond are bonded in a strong tetrahedron pattern making it hard and clear whereas carbon atoms in graphite are bonded in weak covalent bonds making it soft and black. Coal is a combustible sedimentary rock occurring in rock strata in layers or veins called coal beds. Because of pressure and elevated temperature the carbon becomes hard and chunky.

Discuss

Discuss the importance of rocks for the contruction business.
Answer:
Rocks such as marble and granite are used in construction industries. They are cut into stones and are used for building houses, dams, roads, etc. Rocks also provide raw materials such as limestone and gypsum used in the manufacturing of cement.

VALUES & LIFE SKILLS

Rocks and minerals play a very important role in our lives.
Can you imagine modern life without minerals ?
What problems would you face in their absence ?
Answer:
Life without rocks and minerals would be disastrous –
Rocks are of great value to us. Some of the main benefits of- rocks are listed below :

• Soil is formed when rocks gradually break up and disintegrated by mechanical and chemical processes.
• Rocks contain a great variety of minerals that yield metals such as iron, manganese, and copper, which are important raw materials for
  mineral-based manufacturing industries.
  We shall face many problems if rocks and minerals get diminished.

The following problems may exist:

1. Human life will come to an end, as soil is essential for food production and if rocks diminished, it would lead to non¬availability of soil.
2. Mineral-based manufacturing industries will also come to an end.

EXERCISES

1. Granite is an example of intrusive igneous rocks.
2. A category of rock which is formed by the alteration of the parent rock due to heat and pressure is called: metamorphic rocks.
3. Conglomerate is an example of sedimentary rocks. .
4. Sedimentary rocks are formed from sediments accumulated over long periods.
5. Sedimentary rock such as limestone change into marble.

B. Write True or False. Rewrite the false statements correctly :

1. Minerals are organic substances.
Answer. False.
Correct : Minerals are inorganic substances.

2. Basalt is an example of an intrusive igneous rock.
Answer. False.
Correct : Basalt is an example of an extrusive igneous rock.

3. Sedimentary rocks are formed by the cooling and solidification of molten rock called magma.
Answer. False.
Correct : Igneous rocks are formed by the cooling and solidification of molten rock called magma.

4. Igneous and sedimentary rocks can change into metamorphic rocks.
Answer. True.

5. Rocks are used in construction industries.
Answer. True.

C. Answer the following questions in brief:

Question 1.
What is crust ?
Answer:
The outermost layer of the Earth is the crust. Crust is the thinnest layer of the earth.

Question 2.
Differentiate between SIAL and SIMA.
Answer:
SIAL

1. It is the upper layer of the earth.
2. it is made up of silica and aluminium.

SIMA

1. It is the lower layer of the earth.
2. It is made up of magnesium and silica.

Question 3.
State two characteristics of the mantle.
Answer:

1. The mantle is semi-solid.
2. It is rich in iron and magnesium.
3. This layer is about 2,850 km wide. Its average density is between 3.5 and 5.5.

Question 4.
What is the difference between the inner and the outer core ?
Answer:
Inner core

1. Inner most layer of the Earth.
2. Solid ball of iron and nickel.
3. Has a radius of 1220 km.

Outer core

1. Surrounds the inner core.
2. Made of liquid iron and nickel.
3. Has a radius of Approx. 2300 km.

Question 5.
What are minerals?
Answer:
Minerals are natural inorganic substances having a crystalline form with definite physical and chemical properties. The most common minerals in the earth’s crust are silica, quartz, feldspar, mica, calcite, dolomite, gypsum, etc. There are about 2,000 minerals in the earth’s crust and these combine differently to form various kinds of rocks.

Question 6.
Give an example of an intrusive igneous rock.
Answer:
Instrusive rocks, which form large crystals at some depth in the earth’s crust example : granite, basalt.

Question 7.
Classify the following rocks as igneous, sedimentary, and metamorphic: gneiss, coal, shale, granite, gypsum, marble, sandstone, basalt, limestone, schist
Answer:
Minerals — Rocks
Gneiss — Metamorphic
Coal — Sedimentary
Shale — Sedimentary
Granite — Igneous
Gypsum — Sedimentary
Marble — Metamorphic
Sandstone — Sedimentary
Basalt — Igneous
Limestone — Sedimentary
Schist — Metamorphic

D. Answer the following questions in one or two paragraphs :

Question 1.
Explain the structure of the earth’s interior ?
Answer:
The earth’s interior is divided into three main layers — the crust is the outermost layer, the mantle is the intermediate layer, and the core is the innermost layer of the earth.

Question 2.
How are rocks different from minerals?
Answer:
Minerals are natural inorganic substances having a crystalline form with definite physical and chemical properties whereas rocks are made up of a combination of different minerals compacted together. There are about 2,000 minerals in the earth’s crust and these combine differently to form various kinds of rocks.

Question 3.
How are igneous rocks formed?
Answer:
Igneous rocks are formed by the cooling and solidification of molten rock called magma, which lies beneath the earth’s crust. These rocks are crystalline and compact. They do not occur in layers or strata nor do they contain fossils.
The cooling and solidification may take place at some depth within the earth or at the surface. The molten magma that reaches the surface of the earth is called lava. Thus, there are two types of igneous rocks classified on the basis of their place of origin – intrusive rocks, which form at some depth in the earth’s crust and extrusive rocks which form at or near the surface of the earth.

Question 4.
How do acidic igneous rocks differ from basic igneous rocks ?
Answer:
Igneous rocks may also be classified as acidic or basic depending on their composition. The acidic rocks contain more than 65% silica and very low percentage of oxides. These are Arundeep’s Self-Help to Voyage-7 less dense and light coloured. For example, granite. The basic rocks contain low percentage of silica and high percentage of oxides. These are dense and dark coloured. For example, basalt.

Question 5.
How are sedimentary rocks formed ?
Answer:
Sedimentary rocks are formed from sediments accumulated over long periods, usually under water on the floors of shallow seas, rivers and lakes. These rocks are non-crystalline and are found in layers or strata and contain fossils. Conglomerate, sandstone, limestone, chalk, calcite, and dolomite are example of sedimentary rocks. Sedimentary rocks are divided into various types depending on how they are formed.

1. Mechanically formed sedimentary rocks :
   These rocks have been formed by the accumulation of materials derived from other rocks which have been cemented together.
   Examples – conglomerate (rounded fragments), breccia (angular fragments).
2. Organically formed sedimentary rocks :
   These rocks have been formed by the accumulation of the remains of living organisms.
   Examples – calcareous rocks such as limestone and chalk.
3. Chemically formed sedimentary rocks:
   These rocks have been commonly formed by the process of evaporation of water containing salts in solution.
   Examples – rock salt, gypsum, potash, nitrates, calcite, and dolomite.

Question 6.
What are metamorphic rocks ?
Answer:
Metamorphic rocks are those rocks which are formed by the metamorphism of pre-existing rocks due to high temperature or pressure or both. Igneous and sedimentary rocks completely changes over long periods of time because of movements in the earth’s crust and volcanic or mountain building activity.
Transformation of rocks due to high temperature is called thermal metamorphism. Alteration of parent rock due to pressure exerted on rocks from the earth’s movements is called dynamic metamorphism.

E. Picture study

The photograph shows you a type of rock that is widely used in the construction industry.

Question 1.
Name the type of rock.
Answer:
The type of rock is chemically formed sedimentary rock as limestone becomes marble. It is marble.

Question 2.
How is it formed ?
Answer:
Sedimentary rocks are formed from sediment accumulated over long periods, usually under water on the floors of shallow seas, rivers, and lakes. These rocks are fromed by the process of evaporation of water containing in limestone which becomes marble.

LET’S DO SOMETHING

With the help of your teacher, collect different types of rocks such as granite, sandstone, limestone, marble, slate, graphite, etc. and prepare a chart containing information about their colour, hardness, texture, and permeability.
Answer:
Do it Yourself.