Maharashtra Board Class 11 Geography Chapter 2 Weathering and Mass Wasting Solutions

Complete the Chain

 

Question 1. Complete the following chain:

Rock type	Name of the rock	Dominant type of weathering
(1) Igneous	(A) Limestone	(I) Shattering
(2) Sedimentary	(B) Marble	(II) Block disintegration
(3) Metamorphic	(C) Granite	(III) Carbonation

Answer: The correctly matched chain showing the relationship between rock types, specific rocks, and their dominant weathering processes is given below.

Rock type	Name of the rock	Dominant type of weathering
(1) Igneous	(C) Granite	(II) Block disintegration
(2) Sedimentary	(A) Limestone	(III) Carbonation
(3) Metamorphic	(B) Marble	(I) Shattering

In simple words: Different types of rocks break down in different ways. Granite blocks break apart due to temperature changes, limestone dissolves easily when mixed with rainwater and carbon dioxide, and hard marble splits or shatters under pressure.

🎯 Exam Tip: Memorize the relationship between rock types and their specific weathering processes, as matching questions are highly scoring and straightforward.

 

Question. Match the rock types with their names and dominant types of weathering:

Rock type	Name of the rock	Dominant type of weathering
(1) Igneous	(1) Dolomite	(1) Physical Weathering
(2) Sedimentary	(2) Slate	(2) Chemical Weathering
(3) Metamorphic	(3) Basalt
	(4) Limestone
	(5) Granite

Answer:

Rock type	Name of the rock	Dominant type of weathering
(1) Igneous	(1) Basalt Granite	(1) Physical Weathering Physical Weathering
(2) Sedimentary	(2) Dolomite Limestone	(2) Chemical Weathering Chemical Weathering
(3) Metamorphic	(3) Slate	(3) Physical Weathering

In simple words: Different types of rocks like basalt, dolomite, and slate undergo different types of weathering (either physical or chemical) depending on their unique mineral composition.

🎯 Exam Tip: Make sure to pair each rock type with its correct examples and weathering processes to secure full marks in matching questions.

Identify the Correct Correlation

A : Assertion
R : Reasoning

 

Question 1.
A – In areas of high rainfall, slides are very common.
R – Types of mass wasting movements are dependent on a region’s climate.
(a) Only A is correct.
(b) Only R is correct.
(c) Both A and R are correct and R is the correct explanation of A.
(d) Both A and R are correct but R is not the correct explanation of A.
Answer: (d) Both A and R are correct but R is not the correct explanation of A.
In simple words: Heavy rain makes land slide easily, and climate does affect how soil and rocks move downhill, but the second statement does not directly explain why slides happen in rainy areas.

🎯 Exam Tip: When solving assertion-reason questions, read both statements independently first to check if they are true, then connect them with 'because' to see if the reason explains the assertion.

 

Question 2.
A – Gravity is a major factor in mass wasting.

 

Question. R – Gravity pulls all things down to the earth’s surface.
(a) Only A is correct.
(b) Only R is correct.
(c) Both A and R are correct and R is the correct explanation of A.
(d) Both A and R are correct but R is not the correct explanation of A.
Answer: (c) Both A and R are correct and R is the correct explanation of A.
In simple words: Gravity is the natural force that pulls everything down toward the Earth's center, which is why materials move downslope.

🎯 Exam Tip: When the reason directly explains the cause of the assertion, always choose the option stating that R is the correct explanation of A.

 

Question 3. A – Freeze and thaw weathering is common in desert areas.
R – Water gets into cracks and breaks the rocks.
(a) Only A is correct.
(b) Only R is correct.
(c) Both A and R are correct and R is the correct explanation of A.
(d) Both A and R are correct but R is not the correct explanation of A.
Answer: (d) Both A and R are correct but R is not the correct explanation of A.
In simple words: Both statements are true on their own, but water freezing in cracks is not the main reason why freeze-thaw weathering is common in deserts, where extreme temperature changes are the primary factor.

🎯 Exam Tip: Be careful with desert weathering questions; remember that high temperature variation is the main driver, even if water action still occurs.

 

Question 4. A – Surface water helps solifluction.
R – Water table is responsible for the same.
(a) Only A is correct.
(b) Only R is correct.
(c) Both A and R are correct and R is the correct explanation of A.
(d) Both A and R are correct but R is not the correct explanation of A.
Answer: (a) Only A is correct.
In simple words: Surface water makes the topsoil wet and muddy, causing it to slide slowly downslope, but the deep underground water table does not cause this surface movement.

🎯 Exam Tip: Solifluction is a surface process restricted to the upper saturated soil layer, so the deep water table has no role in it.

3. Identify the Correct Group

 

Question 1. Identify the correct group from the table below:

A	B	C	D
(1) Oxidation	(1) Solution	(1) Fall	(1) Pressure
(2) Carbonation	(2) Salt weathering	(2) Creep	(2) Temperature
(3) Freeze thaw weathering	(3) Oxidation	(3) Slide	(3) Slope

Answer: Group C (Fall, Creep, Slide)
In simple words: Group C is the correct group because fall, creep, and slide are all different types of mass movements where soil and rocks move down a slope under gravity.

🎯 Exam Tip: To find the correct group, look for the column where all three terms belong to the exact same geological category or process.

Give Geographical Reasons

 

Question 1. Temperature is the main factor behind granular weathering.
Answer: Temperature is the main factor behind granular weathering because:
1. In hot desert areas, the diurnal range of temperature is high.
2. As the temperature increases with the rising sun, the rock gets heated and expands, and then it cools down and contracts with the decrease in temperature.
3. The minerals in the rock react differently to the temperature increase due to continuous heating and cooling.
4. Consequently, it leads to the development of stress within the rock and molecular or granular disintegration takes place. This constant tension eventually causes the rock to break down into smaller, individual grains.
In simple words: In hot deserts, rocks get very hot and expand during the day, then cool down and shrink at night. Because different minerals in the rock expand and shrink at different rates, the rock experiences stress and eventually crumbles into small sand-like grains.

🎯 Exam Tip: Be sure to mention the "diurnal range of temperature" and explain how different minerals expand and contract at different rates to cause stress in the rock.

 

Question 2. Human is an agent of weathering.
Answer: Human is an agent of weathering because:
1. Man is a biological agent of weathering. Due to economic and technological development, man has become the most powerful agent of weathering and erosion.
2. Mining, blasting of hills and ridges for road and dam construction, and quarrying for industrial and building materials, etc., results in a fast rate of disintegration of rocks.
3. Man accelerates the rate of weathering on hill slopes through activities like deforestation, agriculture, and urban development.
In simple words: Humans act as living forces that break down rocks very quickly through activities like mining, blasting hills to build roads, and cutting down trees on slopes.

🎯 Exam Tip: Remember to classify humans as a "biological agent" of weathering and list practical examples like mining and deforestation to support your answer.

 

Question 3. Slope is a major factor in mass wasting.
Answer: Slope is a major factor in mass wasting because gravity acts directly on sloped surfaces, pulling loose materials downward. On steeper slopes, the downslope force of gravity is much stronger, easily overcoming the resisting forces of friction and cohesion that hold soil and rocks in place. Additionally, water accumulation on steep slopes increases the weight of the debris and lubricates the particles, significantly accelerating the downward movement of soil and rock.
In simple words: Gravity pulls things down steep hills much more easily than flat ground. The steeper the hill, the faster and easier it is for rocks and soil to slide down.

🎯 Exam Tip: Explain the role of gravity and how steepness increases the likelihood of materials sliding down to get full marks.

 

Question 3. Slope is a major factor in mass wasting.
Answer: Slope is a major factor in mass wasting because-
1. Mass wasting is the down-slope movement of loose mixture of soil, land and rock particles by the force of gravity.
2. In mass wasting the materials come down the slope without the aid of transporting medium like running water, ice or wind.
3. Mass wasting occurs continuously on all slopes.
4. Some act very slowly, others very suddenly, often with disastrous results. Gravity acts as the primary driving force that pulls materials downward along these inclined surfaces.
In simple words: Mass wasting happens when gravity pulls soil and rocks down a slope. Steeper slopes make it much easier for these materials to slide down without needing water or wind to carry them.

🎯 Exam Tip: When explaining mass wasting, always highlight gravity as the primary force and mention that no transporting medium like water or wind is active here.

 

Question 4. Oxidation changes the size and colour of the rocks.
Answer: Oxidation changes the size and colour of the rocks because-
1. Oxygen in the air and water reacts with certain elements in the minerals inside the rock.
2. In this process, the minerals in the rock react with the oxygen present in the air or water.
3. Metals, particularly iron and aluminium, commonly oxidize forming iron or aluminium oxides. It is also called rusting.
4. These oxides are larger in volume than in the original rocks.
5. The iron oxides are red in colour and aluminium oxides are yellow.
6. Thus, oxidation changes size and colour of the rock. This chemical reaction weakens the overall structure of the rock over time.
In simple words: When oxygen in the air or water reacts with metals inside rocks, it causes rusting. This chemical change makes the rocks swell up in size and turn red or yellow.

🎯 Exam Tip: Remember to mention the specific color changes (iron turns red, aluminum turns yellow) and the increase in volume to secure full marks.

 

Question 5. Effect of mass movement will be greater along the western slope of the Sahyadri’s than the eastern slope.
Answer: Effect of the mass movement will be greater along the western slope of the Sahyadri’s than the eastern slope because-
1. The western slope of the Sahyadri’s are steeper than the eastern slopes.
2. The western slopes receive more rainfall than the eastern slopes as a result mass movement is greater in western slopes than eastern slopes. Heavy moisture lubricates the soil and increases its weight, making landslides far more common.
In simple words: The western side of the Sahyadri mountains is much steeper and gets a lot more rain than the eastern side. This combination of steepness and heavy water makes rocks and soil slide down much more easily.

🎯 Exam Tip: Contrast both factors—slope steepness and rainfall levels—for both the western and eastern slopes to write a complete answer.

5. Write Short Notes On

 

Question 1. Gravity and Solifluction
Answer:
Gravity:
1. It is the main force responsible for mass movements.
2. It is a force that acts everywhere on the earth’s surface, pulling everything down.
3. If the friction on the rock is stronger than gravity for a particular slope, the rock material is likely to stay.
4. But if the gravity is stronger, movement will occur in the direction of the slope.

Solifluction:
1. Solifluction is the name for the slow downhill creep of soil, which occurs in a variety of climatic conditions.
2. It occurs in periglacial or alpine regions.
3. As permafrost is impermeable to water, soil overlying may become oversaturated and slide slopes down under the pull of gravity. Gravity acts as the primary driving force behind this movement.
In simple words: Gravity is the natural pull that drags rocks and soil down slopes, while solifluction is a specific slow movement of wet soil over frozen ground in cold regions.

🎯 Exam Tip: Clearly distinguish between gravity as a universal force and solifluction as a specific process occurring in cold, periglacial environments to score full marks.

 

Question 2. Role of water in mass wasting
Answer:
1. Although water is not always directly involved as a transporting medium but it plays an important role in mass wasting.
2. Addition of water from rainfall or snowfall or melting of snow makes the material on the slope heavier.
3. Water can reduce the friction along a sliding surface, making it much easier for gravity to pull the loose material downward.
In simple words: Water makes soil and rocks on a slope heavier and acts like a lubricant, reducing friction so that materials slide down easily.

🎯 Exam Tip: Remember to highlight the dual role of water: adding weight (lubrication) and reducing friction along the slip plane.

 

Question 3. Exfoliation
Answer:
1. Because of the overlying rocks, the rocks beneath the surface experience a lot of pressure.
2. The exposed part of the rock heats more while the inner part is comparatively cooler.
3. As a result, the outer layer of the rocks fall apart from the main rock just as we peel off onion. This peeling process is highly visible in arid regions where temperature fluctuations are extreme.
In simple words: Exfoliation is when the outer layers of a rock peel off like onion skins. This happens because the outside of the rock gets hot and expands, while the inside stays cool.

🎯 Exam Tip: Remember the onion analogy when explaining exfoliation, as it helps the examiner understand that you grasp the concept of layering and peeling.

 

Question 4. Weathering and homogeneity in rocks
Answer:
1. Weathering is the physical or chemical breakdown of rocks into small pieces due to various reasons like weather conditions, temperature, and water, living organisms like humans, algae, fungi, etc.
2. Weathering depend upon the texture of the rock. Those rocks which have joints on layers break easily than rocks which are homogeneous. Generally, sedimentary rocks break easily than igneous rocks as sedimentary rocks are formed by layering.
3. Sediments brought down by the river are deposited in layers, thus sedimentary rocks are soft and porous, and can be broken easily.
4. Igneous rocks are formed by cooling and solidification of molten magma. Hence, they are hard and non-porous and cannot be broken so easily.
5. Thus, sedimentary rocks are more subjected to weathering than the igneous rocks. This difference in durability highlights how rock structure directly influences landscape erosion rates.
In simple words: Weathering is how rocks break down. Rocks with layers or cracks (like sedimentary rocks) break easily, while uniform and solid rocks (like igneous rocks) are much harder to break down.

🎯 Exam Tip: Clearly contrast sedimentary and igneous rocks in your answer to show how homogeneity affects the rate of weathering.

 

Question 5. Carbonation
Answer:
1. The decomposition of dead matter in the soil produces \( \text{CO}_2 \).
2. This \( \text{CO}_2 \) and the \( \text{CO}_2 \) in the air reacts with minerals in the rocks.
3. Minerals such as feldspar and carbonates decompose when this happens. This chemical reaction is particularly effective in dissolving limestone landscapes over long periods.
In simple words: Carbonation is a chemical process where carbon dioxide reacts with water and minerals in rocks. This reaction causes certain minerals to break down and dissolve.

🎯 Exam Tip: Mention \( \text{CO}_2 \) (carbon dioxide) as the key gas responsible for carbonation to secure full marks in chemical weathering questions.

Draw a Neat and Labelled Diagram For:

 

Question 1. Freeze and thaw weathering
Answer: The diagram of freeze-thaw weathering illustrates the following stages:
• Stage 1: Water collects in rock crevices or cracks.
• Stage 2: As the temperature drops below freezing point, the water freezes into ice and expands by about 9% in volume, exerting immense pressure on the surrounding rock.
• Stage 3: When the temperature rises, the ice melts (thaws), relieving the pressure. Repeated cycles of freezing and thawing widen the cracks, eventually causing the rock to split and break apart. This physical process is highly active in high-altitude and polar regions.
In simple words: Water gets into cracks in rocks, turns to ice and expands when it freezes, pushing the rock apart until it cracks and breaks.

🎯 Exam Tip: When drawing this diagram, clearly label the water entering the crack, the expansion of ice, and the final split of the rock to show the complete cycle.

 

Question 2. Block disintegration
Answer: The diagram of block disintegration illustrates the following features:
• Thermal Expansion: During the day, high temperatures cause the outer layers of the rock to expand.
• Thermal Contraction: At night, low temperatures cause the rock to contract.
• Joint Splitting: This continuous expansion and contraction exerts stress along existing joints and cracks, causing the rock to split into large rectangular blocks. This phenomenon is most common in arid desert environments with high diurnal temperature ranges.
In simple words: Rocks expand in the hot sun during the day and shrink in the cold night, which makes them crack and break apart into large block-like pieces.

🎯 Exam Tip: Draw distinct rectangular blocks with clear joint lines to represent how the rock splits along its natural weaknesses.

 

Question 3. Biological Weathering
Answer: The diagram of biological weathering illustrates the following processes:
• Plant Roots: Roots of trees and plants grow into existing cracks in rocks. As the roots grow thicker, they exert pressure on the rock, widening the cracks and splitting the rock.
• Burrowing Animals: Animals like rabbits, earthworms, and rodents dig burrows, exposing fresh rock surfaces to weathering agents.
• Lichens and Mosses: Microorganisms grow on rock surfaces and produce organic acids that chemically break down the minerals. This biological activity significantly accelerates the overall rate of soil formation.
In simple words: Plants and animals break rocks apart when roots grow into cracks or when animals dig holes in the ground.

🎯 Exam Tip: Show a tree root growing deep into a rock crack and splitting it apart, as this is the most common and easily graded diagram for biological weathering.

Answer in Detail

 

Question 1. Explain with examples the process of weathering happening in Konkan.
Answer:
1. Konkan, also known as the Konkan Coast is a rugged, section of the western coastline of India.
2. The region is divided into North Konkan including Mumbai, Thane and Raigad districts whereas South Konkan include Ratnagiri and Sindhudurg districts.
3. Laterite rocks-occur in the form of plateaus at Konkan strip. High altitude laterite plateaus are found is Sitara, Kolhapur, Ratnagiri and Sindhudurg district.
4. In the laterite rocks soft silica matter is present.
5. Because of high rainfall exposed rocks become empty to wash out of soft silica matter.
6. Laterite soil is formed by laterite rock in high elevation. The soil contains has high concentration of ferrous and aluminium. This soil is very stony because of the presence of weathering fragments of iron concentrations.
7. Oxygen in the air and water reacts with certain elements in the minerals in the rock. The metals in the rock particularly iron and aluminium oxidise and form iron and aluminium oxides. Thus, chemical weathering takes place.
8. Laterite soil is found in Mahabaleshwar, Southern parts of Mahabaleshwar, around Bhima Shankar and Matheran. Thus, chemical and mechanical weathering is found. This unique combination of heavy rainfall and geological structure shapes the entire landscape of the region.
In simple words: In Konkan, heavy rain washes away soft minerals like silica from the rocks, leaving behind iron and aluminium. This process, along with reaction with oxygen, forms hard red laterite soil and rocks through chemical weathering.

🎯 Exam Tip: To score full marks, make sure to highlight the role of heavy rainfall and the chemical reaction of iron and aluminium with oxygen (oxidation) as key drivers of weathering in Konkan.

Question 2. Explain the correlation between Himalayas and mass movements. Give examples wherever necessary.
Answer:
1. Mass movements occur in hilly, mountainous or plateau areas. The steeper the slope more the occurrences of mass movement.
2. The Himalayas have greatest relief, high potential energy, high seismic activity, steep slopes, strong weathering, great snow fall etc.
3. Due to slope, gradient, massive rockslides, debris flow takes place.
4. Steep gradient of precipitation and temperature produce mass movement that loads glacier surface and chokes, rivers with sediments.
5. For example, in Kosi river basin of Himalayas of central Nepal, because of deep weathering, high seismic activity, river undercutting, deforestation and heavy precipitation, especially during the summer months, mass movements are most frequent in highly jointed, sheared, intensely folded and fault rocks. These geological factors make the region highly vulnerable to sudden environmental changes.
6. Thus, in short, in the Himalayan region, due to steep slope, melting of glaciers, precipitation, seismic activity, mass movement takes place on a larger scale.
In simple words: The Himalayas have very steep slopes, heavy snow, and frequent earthquakes, which cause rocks and soil to slide down easily. This movement is especially common during heavy rains or when glaciers melt.

🎯 Exam Tip: To score full marks, list specific factors like steep slopes, seismic activity, and precipitation, and always include the Kosi river basin example.

 

11th Geography Digest Chapter 2 Weathering and Mass Wasting Intext Questions and Answers

 

Let’s Recall (Textbook Page No. 15)

Study the diagram in fig 2.1 and answer the following questions.

Diagram Nodes (Rock Cycle):

• Weathering or erosion of rocks at surface
• Erosion and transportation
• Deposition
• Layering
• Sedimentary rocks
• Re-crystallisation and metamorphism
• Metamorphic rocks
• Melting of rocks
• Magma chamber
• Solidification of magma
• Igneous rocks
• Lava
• Magma

 

Question 1. Identify the types of rocks shown in the diagram.
Answer: Igneous, sedimentary and metamorphic rocks are shown in the diagram. These three main categories represent the entire rock cycle.
In simple words: The three types of rocks shown in the picture are igneous, sedimentary, and metamorphic rocks.

🎯 Exam Tip: Clearly list all three major rock types to secure full marks in classification questions.

 

Question 2. Arrange the rocks according to their chronology of origin.
Answer: Igneous, sedimentary and metamorphic rocks. This order represents how they typically form one after another over geological time.
In simple words: First come igneous rocks, then sedimentary rocks, and finally metamorphic rocks.

🎯 Exam Tip: Remember that igneous rocks are also called primary rocks because they are formed first from cooled magma.

 

Question 3. Explain how sedimentary rocks are formed.
Answer: Sedimentary rocks are formed from layering upon layering of all the organic (dead remains of plants and animals) and inorganic (sand, silt, clay, gravel, etc.) material in a depression or on low lying area. If there are cementing material like limestone, hardening and compaction takes place, then sedimentary rocks are formed. Over millions of years, these compressed layers turn into solid rock strata.
In simple words: Sedimentary rocks are made when layers of sand, mud, and dead plants pile up in low areas and get squeezed tightly together over a long time until they harden into rock.

🎯 Exam Tip: Use key terms like "layering", "compaction", and "cementing" to explain the formation of sedimentary rocks clearly.

 

Question 4. Think of all the factors which may break the rocks into smaller pieces.
Answer: Heat, pressure, water, wind, animals, plants etc., can break rocks into smaller pieces. These natural forces work continuously over long periods to reshape the Earth's surface.
In simple words: Rocks break down because of natural elements like weather, water, and living things.

🎯 Exam Tip: List both physical factors (like heat and water) and biological factors (like plants and animals) to get full marks.

 

Question 5. Which type of rock will break easily as compared to others? Why?
Answer:
1. Sedimentary rocks will break easily as they are formed by layering of sediments and thus, they are soft and porous and are broken easily.
2. Igneous rocks are formed from cooling and solidification of molten magma; hence they are hard and non-porous.
3. The metamorphic rocks too cannot be broken easily as they are formed from heat and pressure. This makes their crystalline structure highly resistant to weathering.
In simple words: Sedimentary rocks break easily because they are made of soft, pressed layers, while igneous and metamorphic rocks are much harder and tougher.

🎯 Exam Tip: Clearly compare the structure of sedimentary rocks with igneous and metamorphic rocks to explain why they differ in strength.

Think About It

 

Question 1. In which regions will freeze-thaw weathering not be effective? (Textbook Page No. 17)
Answer: Freeze-thaw weathering will not be effective on the cold polar regions as the soil cover and rocks are very little on the polar areas and moreover, there is snow everywhere. Similarly, it is ineffective in extremely hot and dry desert regions where moisture is completely absent.
In simple words: Freeze-thaw weathering needs water to freeze and melt repeatedly, so it doesn't work well in places that are always covered in deep snow or have no water at all.

🎯 Exam Tip: Explain that freeze-thaw weathering requires temperature fluctuations around the freezing point to be effective.

 

Question 2. Besides climatic factors, rock type and structure, can you think of some more factors that affect weathering? (Textbook Page No. 19)
Answer: Plants, animals, micro-organisms, humans are some more factors that affect weathering. Human activities like mining, construction, and agriculture significantly accelerate the breakdown of rocks.
In simple words: Living things, including plants, burrowing animals, and humans, also help break down rocks through their daily activities.

🎯 Exam Tip: Remember to mention biological weathering agents like plant roots and human activities alongside climatic factors.

 

Question 3. Can tectonic forces be responsible for mass movement? (Textbook Page No. 25)
Answer: Yes, tectonic forces can be responsible for mass movement. Earthquakes and volcanic eruptions caused by tectonic activities destabilize slopes, triggering sudden and massive landslides or rockfalls.
In simple words: Yes, when the earth shakes during an earthquake, it can loosen rocks and soil on hills, causing them to slide down quickly.

🎯 Exam Tip: Use examples like earthquakes triggering landslides to clearly demonstrate how tectonic forces cause mass movement.

 

Question 4. There is a shift of materials in mass movement as well as in transportation from one place to the other. So, why can’t both not be treated as one and the same? (Textbook Page No. 25)
Answer: Mass movement is caused by abrupt movement and freefall of loosened rock particles because of gravity and friction falling towards the surface, whereas transportation is carrying of rock materials with the help of agents of erosion such as water, wind, air, ice, etc. Thus, they are not same. Gravity acts as the primary driving force in mass movements without requiring an active transporting medium.
In simple words: Mass movement is when rocks and soil slide down a slope mainly due to gravity, whereas transportation involves active agents like water or wind carrying materials over distances.

🎯 Exam Tip: To get full marks, clearly highlight the role of gravity in mass movement versus the role of external agents like water and wind in transportation.

Use Your Brain Power!

 

Question 1. Can animals and plants also influence weathering? Will that be physical or chemical weathering? Which type of weathering does stone quarrying cause? (Textbook Page No. 19)
Answer: Yes, burrowing animals widen the fissures in the rocks. Rocks become weak and disintegrate. The roots of the trees and other plants penetrate in the soil, they grow in size, exert pressure on rocks, widen cracks in the rocks and rocks break. Many microscopic organisms such as algae, lichens, bacteria, moss etc produce chemicals and they break down the outer layer of the rock. These chemicals are responsible for physical and chemical weathering of rocks. The stone quarrying causes the anthropogenic weathering. This highlights how biological processes and human activities can significantly accelerate the breakdown of geological structures.
In simple words: Yes, plants and animals cause weathering. Plant roots and burrowing animals physically break rocks apart, while microbes release chemicals that dissolve them, and human quarrying represents man-made weathering.

🎯 Exam Tip: Be sure to mention all three aspects: physical weathering by roots/animals, chemical weathering by microorganisms, and anthropogenic weathering by quarrying.

 

Question 1. Which type of weathering will be dominant here?
Answer: Physical weathering will be dominant here. This is because the extreme temperature variations cause rocks to expand and contract repeatedly.
In simple words: Physical weathering happens when rocks crack and break apart due to temperature changes without changing what they are made of.

🎯 Exam Tip: Clearly state the type of weathering first before explaining the climatic reasons behind it to secure full marks.

 

Question 2. Where will such a region be found?
Answer: Such a region will be found in permafrost conditions, alpine and periglacial regions. These areas are characterized by extremely cold temperatures and frozen ground.
In simple words: These cold regions are found high up in the mountains or near the polar areas where the ground stays frozen.

🎯 Exam Tip: Remember to list all three regions—permafrost, alpine, and periglacial—as they are key terms examiners look for.

 

Question 1. Complete the table by using the words: intense, moderate, slight and very slight or no weathering. (Textbook Page No. 20)
Answer: These completed tables show how temperature and rainfall work together to break down rocks.

Rate of Physical Weathering:

Temperature / Rainfall	High rainfall	Moderate rainfall	Low rainfall
High temperature	Intense	Moderate	Intense
Moderate temperature	Intense	Moderate	Slight
Low temperature	Moderate	Slight	No weathering

Rate of Chemical Weathering:

Temperature / Rainfall	High rainfall	Moderate rainfall	Low rainfall
High temperature	Intense	Moderate	Moderate
Moderate temperature	Intense	Moderate	Slight
Low temperature	Moderate	Slight	Slight

In simple words: These tables show how different combinations of heat and rain cause rocks to weather quickly, slowly, or not at all.

🎯 Exam Tip: Notice that high temperature and high rainfall always lead to intense weathering for both physical and chemical types.

 

Can You Tell? (Textbook Page No. 21)

1. See the diagram given in fig 2.10 and answer the following questions.

• Rock layers shown in diagram: A, B, C, D, E, F

 

Question 1. Which rock layer has experienced the most weathering?
Answer: Rock layer C has experienced the most weathering. This is clearly visible from its highly degraded and fragmented appearance in the geological section.
In simple words: Layer C is the most broken down because it is weaker and more exposed to nature. This makes it wear away much faster than the other layers.

🎯 Exam Tip: Identify the layer that looks most broken or reduced in size to determine the highest rate of weathering.

 

Question 2. Which rock layer has experienced the least weathering?
Answer: Rock layer B has experienced the least weathering. It remains largely intact and prominent compared to the surrounding layers.
In simple words: Layer B is the least damaged because it is made of very tough material. It can withstand wind and water without breaking easily.

🎯 Exam Tip: Look for the layer that retains its original shape and thickness to identify the least weathered rock.

 

Question 3. What could be the reason behind difference in weathering?
Answer: Rock C has lot of fractures and joints so it got weathered easily. Rock B might have been a hard rock, more resistant, so weathering process is slow. The physical and chemical characteristics of rocks play a major role in determining their rate of decomposition.
In simple words: Rocks weather at different speeds depending on how hard they are and if they have cracks. Soft, cracked rocks break down quickly, while hard, solid rocks last much longer.

🎯 Exam Tip: Always mention factors like rock hardness, presence of joints, and mineral composition when explaining differences in weathering rates.

 

2. The satellite images given in fig. 2.11 A and B belong to the same location but different timeline. Study the images and answer the following questions. (Textbook Page No. 21)

 

Question 1. Compare the images and tell what differences do you find in these images?
Answer: Image 2.11 (A) shows maximum area under vegetation. Image 2.11 (B) shows development in form of settlements and transportation routes. This indicates a significant change in land use over the eight-year period.
In simple words: When we compare the two pictures, the older one has a lot of green trees and plants, while the newer one shows more houses, roads, and human construction.

🎯 Exam Tip: When comparing satellite images, look for changes in green cover (vegetation) versus grey/brown areas (buildings and roads) to identify development.

 

Question 2. In 2019, what does the patch of land going from north-west to south-east signify? Why was it not there in 2011 image?
Answer: The sweeping portion from north-west to south-east is visible in satellite image of 2019. This is because the village is located at the foothills. The rain and slope were responsible for the mudslide. Heavy rainfall and absence of vegetation aggravated the landslide, causing a massive flow of mud and debris down the slope.
In simple words: The long patch of bare land shows where a mudslide happened in 2019. It was not there in 2011 because the heavy rains and lack of trees that caused the soil to slide down the hill had not occurred yet.

🎯 Exam Tip: Clearly link the physical features of the terrain, like steep slopes and lack of vegetation, to natural disasters like mudslides to score full marks.

Question 3. To what extent is the climate of a place responsible for this disaster?
Answer: Climate plays an important role for the disaster. Heavy rainfall makes soil to move from the surface of the mountain towards the foothills. This movement is often accelerated on steeper slopes where gravity acts more strongly.
In simple words: When it rains heavily, the water washes the loose soil down the mountain side, causing landslides.

🎯 Exam Tip: Always mention specific climatic factors like heavy rainfall and their direct physical impact on the soil.

 

Question 4. Which other factors are responsible for the disaster?
Answer: Deforestation and absence of vegetation are responsible for this. Without tree roots to bind the soil together, the ground becomes highly unstable during heavy rains.
In simple words: Cutting down trees makes the soil loose because there are no roots left to hold it firmly in place.

🎯 Exam Tip: Remember to highlight human activities like deforestation alongside natural factors when discussing environmental disasters.

 

Give It A Try

1. Study the following schematic diagram. It shows the relationship between speed of material and moisture content. Read the index, and answer the following questions. (Textbook Page No. 23)

• Vertical Axis (Speed): From B (Slow) to A (Fast)
• Horizontal Axis (Moisture): From C (Dry) to D (Wet)
• Processes: (1) Creep, (2) Slide, (3) Fall, (4) Flow

 

Question i. What will happen when the weather conditions are dry?
Answer: When weather conditions are dry, the moisture content in the soil is extremely low, which generally prevents rapid flow-like movements but can still lead to dry falls or slow creeps depending on the slope. This lack of water reduces the lubrication that typically triggers massive landslides.
In simple words: In dry weather, the soil does not have water to make it muddy, so it moves very slowly or stays in place unless it falls off a steep cliff.

🎯 Exam Tip: Use the diagram's axes to correlate dry conditions with the corresponding speed and movement types shown in the index.

Question i.
Answer: There will not be moisture content hence speed of material will be low. This lack of lubrication prevents rapid downslope movement.
In simple words: When there is no moisture, the soil and rocks remain dry and move very slowly.

🎯 Exam Tip: Clearly state that moisture acts as a lubricant, and its absence directly reduces the speed of mass movement.

 

Question ii. When will a flow occur?
Answer: Flow will occur when the moisture content as well as speed of material will be high. This rapid movement typically happens during heavy rainfall on steep slopes.
In simple words: A flow happens when the ground is very wet and mud or rocks slide down quickly like a liquid.

🎯 Exam Tip: Remember that both high moisture and high speed are necessary conditions for a flow to occur.

 

Question iii. When will a creep occur?
Answer: Creep will occur when speed of material will be slow. This extremely gradual downslope movement is often imperceptible to the naked eye.
In simple words: Creep is a very slow downhill movement of soil that happens over many years.

🎯 Exam Tip: Highlight 'slow speed' as the defining characteristic of soil creep to secure full marks.

 

Question iv. Now can you enumerate the factors which affect mass wasting?
Answer: Factors such as gravity, slope of land, climate of region, amount of water, material and structure of the rock affect mass wasting. These elements work together to determine how quickly or slowly materials move downslope.
In simple words: Mass wasting is affected by gravity, how steep the hill is, the weather, water, and the type of rocks.

🎯 Exam Tip: List at least four factors clearly, with gravity and slope being the most critical ones.

 

Question 2. On the basis of given points, differentiate between weathering and erosion. (Textbook Page No. 25)
Answer:

Point of Comparison	Weathering	Erosion
Definition	It is the wearing away, breaking, or disintegration of rocks in their original place.	It is the process of wearing away and transportation of rock particles by natural agents.
Movement	It is an in-situ (static) process; there is no motion or transportation of materials.	It is a dynamic process involving the active movement and transport of materials.
Agents	Temperature, frost, water, plants, and animals.	Running water, wind, glaciers, and sea waves.

In simple words: Weathering breaks down rocks where they are, while erosion carries those broken pieces away to new places.

🎯 Exam Tip: Always use a tabular format for distinction questions and highlight the key difference: weathering is static (in-situ) while erosion is dynamic (involves transport).

Think A Little (Textbook Page No. 24)

 

Question. Think of the reason why landslides should be more frequent in foothill zone of the Himalayas and Western Ghats region. Why do landslides not occur in Marathwada in Maharashtra or Maidan area in Karnataka?
Answer: Himalayas are one of the youngest fold mountains of the world. They are formed due to convergent movement of the Indian plate and erosion plate. They are still rising in height. These tectonic movements cause frequent earthquakes in the region resulting into landslides whereas western Ghats lie in the stable Deccan shield less prone to landslides. Additionally, heavy monsoon rainfall in these mountainous terrains acts as a major trigger for slope instability.
In simple words: The Himalayas are young, active mountains that experience earthquakes, and the Western Ghats have steep slopes with heavy rain, making landslides common. Marathwada and Maidan are flat, stable plains where landslides rarely happen.

🎯 Exam Tip: Mention tectonic activity for the Himalayas and the stable nature of the Deccan shield for Marathwada/Maidan to secure full marks.

Himalayas are greater in height than the western Ghats. The slopes are comparatively steep and hence landslides are common in Himalayas whereas, the western Ghats are much lesser in height than the Himalayas hence less prone to landslides as compared to Himalayas.

The perennial rivers in Himalayas carry lots of sediments during rainfall and due to melting of glaciers in the summer thus leading to landslides, whereas, in Western Ghats many rivers are non-perennial and hence less amount of silt and debris in carried as compared to Himalayan rivers. Thus, there is reduction in the chances of landslides, only during the rainy season, landslides occur in Western Ghats region.

Try This (Textbook Page No. 24)

 

Question 1. Different types of materials flow down the slope. Types of mass wasting depend on their speed. Observe the pictures given in figure 2.12. Match the explanation given below with the diagrams. Identify them as slow or rapid movements.

🎯 Exam Tip: When studying mass wasting, always classify the movements clearly into slow (like soil creep) or rapid (like rockfalls and landslides) based on their speed and moisture content to secure full marks.

 

Question 1. Identify the types of mass movements shown in the given figure.
Answer:
• A – Earth flow: Rapid or slow movement of water-saturated clayey or silty materials down a hillside.
• B – Creep: Slowest downslope movement of soil and weathered rock debris, often extremely gradual.
• C – Slump: Rapid sliding of a cohesive mass of rock or soil along a curved slip plane.
• D – Debris flow: Rapid downslope flow of a slurry of soil, rock, and water.
• E – Rockfall: Free-falling of newly detached chunks of bedrock from a cliff or steep slope.
These movements are primarily driven by gravity acting on weathered materials along slopes.
In simple words: Mass movement is when soil, sand, and rocks slide down a slope because of gravity. Some movements like soil creep happen so slowly we can't see them, while others like rockfalls and landslides happen very fast and can be dangerous.

🎯 Exam Tip: Clearly distinguish between rapid and slow mass movements, and remember that water content and slope angle are the key factors determining the speed of these movements.

 

Question 2. Complete the following flow chart. (Textbook Page No. 25)
Answer:
The completed flow chart of Earth Movements is represented below:

• Earth Movements
  • Endogenic (Internal Movements)
    • Continent Building
    • Mountain Building
      • Sudden
        • Earthquake
        • Volcanoes
      • Slow
        • Faulting
        • Folding
  • Exogenic (External Movements)
    • Weathering
    • Erosion
    • Deposition
    • Mass Wasting

In simple words: Earth movements are divided into internal forces (endogenic) like sudden earthquakes and slow mountain building, and external forces (exogenic) like weathering and erosion that shape the surface of the Earth.

🎯 Exam Tip: Draw this flow chart clearly in your exams to easily secure full marks, making sure to correctly distinguish between internal (endogenic) and external (exogenic) processes.