RBSE Solutions Class 11 Physical Geography Chapter 6 Rocks

RBSE Class 11 Physical Geography Chapter 6 Multiple Choice Questions

 

Question 1. Which is the igneous rock out of the following?
(a) Gneiss
(b) Marble
(c) Diamond
(d) Slate
Answer: (d) Slate
In simple words: Igneous rocks are formed when hot molten rock cools down and hardens. Among the choices, slate is a type of igneous rock.

🎯 Exam Tip: Remember the basic definitions for each rock type (igneous, sedimentary, metamorphic) and common examples of each to quickly identify them.

 

Question 3. The rocks in which fossils are not found are:
(a) Layered
(b) Secondary
(c) Igneous
(d) Metamorphic
Answer: (c) Igneous
In simple words: Fossils are usually found in sedimentary rocks, which form from layers of sediment. Igneous rocks come from very hot molten rock, which would destroy any organic matter, so no fossils are found there.

🎯 Exam Tip: Understand the formation processes of different rock types; this helps in deducing their characteristics, such as the presence or absence of fossils.

 

Question 4. Which is the metamorphic rock out of the following?
(a) Granite
(b) Marble
(c) Basalt
(d) None of the options
Answer: (b) Marble
In simple words: Metamorphic rocks are formed when existing rocks change due to heat, pressure, or chemical reactions. Marble is a metamorphic rock that forms from limestone.

🎯 Exam Tip: Learn the common transformations, like limestone to marble or shale to slate, as these are frequently asked examples of metamorphic rocks.

 

Question 5. Which is the sedimentary rock out of the following?
(a) Granite
(b) Limestone
(c) Basalt
(d) Marble
Answer: (b) Limestone
In simple words: Sedimentary rocks are made from bits of other rocks or living things that get pressed together over time. Limestone is a common sedimentary rock formed from the shells and skeletons of marine organisms.

🎯 Exam Tip: Familiarize yourself with examples of each rock type; this helps distinguish them in multiple-choice questions.

RBSE Class 11 Physical Geography Chapter 6 Very Short Answer Type Questions

 

Question 3. Mention the metamorphosed form of any two sedimentary rocks.
Answer: Limestone is a sedimentary rock that changes into marble when it undergoes metamorphism. Coal is another sedimentary rock that transforms into graphite and diamond under metamorphic conditions.
In simple words: Limestone turns into marble, and coal turns into graphite or diamond when they undergo metamorphic changes.

🎯 Exam Tip: Knowing specific examples of how one type of rock changes into another during metamorphism is crucial for such questions.

 

Question 4. Define rock.
Answer: In simple terms, a rock is any hard, natural substance. From a geological point of view, rocks are all the solid materials that make up the Earth's crust.
In simple words: A rock is any hard, natural material that forms part of the Earth's outer layer.

🎯 Exam Tip: Provide a concise definition, clearly stating that rocks form the Earth's crust and are composed of minerals.

 

Question 5. Define the sedimentary rocks.
Answer: Sedimentary rocks are formed when existing rocks break down into smaller pieces, which then gather and build up in layers. These layers can include fossils of living organisms, plant matter, and fragments of other rocks. Over time, these materials get pressed together and harden to form sedimentary rocks.
In simple words: Sedimentary rocks are made from bits of other rocks, dead plants, and animals that pile up in layers and then get squeezed into solid rock.

🎯 Exam Tip: Highlight keywords like "accumulation," "layers," "fossils," and "sediments" when defining sedimentary rocks.

RBSE Class 11 Physical Geography Chapter 6 Short Answer Type Questions

 

Question 1. Mention the features of igneous rocks.
Answer: The features of igneous rocks are:
1. They do not have distinct layers.
2. These rocks are non-porous, meaning they don't have many small holes.
3. They are crystallized, which means they have a crystal structure.
4. Fossils are not found in these rocks because they form from molten material.
5. These rocks are very hard and tough.
6. Physical weathering affects these rocks more than chemical weathering.
7. These rocks often contain valuable metallic minerals.
In simple words: Igneous rocks are hard, have no layers or pores, contain crystals, and are rich in metals, but they don't have fossils.

🎯 Exam Tip: List key characteristics clearly and use simple language to describe each feature of igneous rocks.

 

Question 3. Mention the features of the metamorphic rocks.
Answer: The features of metamorphic rocks are:
1. These are called secondary rocks because they form when other rocks change their shape or structure.
2. They are generally more organized and harder than the original rocks from which they formed.
3. Metamorphic rocks often contain important metallic minerals, making them economically valuable.
4. These rocks are non-porous.
In simple words: Metamorphic rocks are secondary rocks, harder and more organized than their originals, often containing valuable metals, and are non-porous.

🎯 Exam Tip: Focus on how metamorphic rocks are derived from other rocks and the resulting changes in their hardness, structure, and mineral content.

 

Question 4. Mention the names of metamorphic rocks that are made up of sedimentary rocks.
Answer: The following table shows metamorphic rocks formed from sedimentary rocks:

In simple words: Sedimentary rocks like sandstone, limestone, shale, and coal can change into quartzite, marble, slate, and graphite/diamond, respectively, through metamorphism.

🎯 Exam Tip: Memorize specific pairs of parent sedimentary rocks and their corresponding metamorphic rock forms, possibly using a table for quick recall.

RBSE Class 11 Physical Geography Chapter 6 Essay Type Questions

 

Question 1. Classify the rocks and give a detailed description of the metamorphic rocks.
Answer: Rocks on Earth's surface are classified based on how they form, how long they exist, and what they are made of. The main types are Igneous, Sedimentary, and Metamorphic rocks. Here is a classification chart:

Description of Metamorphic Rocks:
Metamorphic rocks are formed when existing rocks undergo significant changes in their properties and structure, without breaking down. These original rocks can be igneous, sedimentary, or even other metamorphic rocks. The changes happen due to intense heat, pressure, and the presence of water.

Features of Metamorphic Rocks:
Metamorphic rocks are secondary rocks, meaning they are formed from other rocks. They are generally harder than their original forms and are non-porous. These rocks often contain metallic minerals in large amounts, making them economically important.

Classification of Metamorphism:
The process of metamorphism is classified into four main types:
1. Thermal Metamorphism: Occurs due to extremely high heat.
2. Regional Metamorphism: Happens over a wide area due to both compression and heat, often found in folded mountain regions. This causes rocks to crystallize or re-crystallize.
3. Hydro Metamorphism: Involves chemical changes in rock minerals through reactions with water. Increased water depth can also add to the pressure, contributing to metamorphism.
4. Thermo - Hydro Metamorphism: This type occurs when hot water acts on rocks, combined with water vapor and pressure.

Classification of Metamorphic Rocks (based on original rock):
Metamorphic rocks are also classified based on the original rock from which they formed. The table below shows some examples:

In simple words: Rocks are divided into igneous, sedimentary, and metamorphic types. Metamorphic rocks are former rocks changed by heat and pressure, making them harder and often full of metals. They can be classified by the type of change (like thermal) or by what original rock they came from.

🎯 Exam Tip: When describing rocks, always mention their formation process, key characteristics, and at least two examples for each type. For classifications, a flowchart or a table can be very effective.

 

Question 2. Classify the igneous rocks and give a detailed description of them.
Answer: Igneous rocks are the first type of rocks to form, so they are also known as Primary Rocks. They do not contain fossils. Igneous rocks are classified based on their mineral composition, texture, how their particles are formed, their shape, and where they formed. The classification is as follows:

(I) Classification of Igneous Rocks on the basis of formation place:

(i) Intrusive Igneous Rocks:
These rocks form when magma cools and solidifies beneath the Earth's surface. They are further divided into two types:

1. Plutonic Rocks: These rocks form when magma cools and hardens deep underground. They usually have large mineral grains. Granite is a prime example of a plutonic rock.
2. Hypabyssal Rocks: These rocks form when magma solidifies in cracks or fissures at shallower depths below the Earth's surface. They often form in shapes like phacoliths and batholiths. The following figures illustrate these forms:

Batholith

Phacolith

(ii) Extrusive Igneous Rocks:
These rocks form when lava erupts onto the Earth's surface and cools rapidly. Because of quick cooling, the mineral grains in these rocks are very small.

(II) Classification of Igneous Rocks on the basis of chemical composition:

1. Acidic Rock: Rocks that contain more than 65% silica are called Acidic Rocks.
2. Basic Rock: Rocks that contain between 45% to 55% silica are called Basic Rocks.
3. Intermediate Rock: Rocks that have silica content between that of Acidic and Basic Rocks.
4. Ultra - Basic Rock: Rocks with less than 45% silica are called Ultra-Basic Rocks.
In simple words: Igneous rocks are primary rocks from molten magma, without fossils. They are classified by where they form (underground as intrusive, or on the surface as extrusive) and by their chemical make-up, specifically how much silica they contain.

🎯 Exam Tip: When classifying igneous rocks, make sure to describe both their formation location (intrusive vs. extrusive) and their chemical composition (acidic, basic, etc.), providing examples for each category.

 

Question 3. Classify the Sedimentary Rocks and give a detailed description of them.
Answer: Sedimentary rocks form after igneous rocks, from various materials and sediments. These rocks are created by the accumulation of layers of material, including fossils of living organisms, plant remains, and rock fragments. Sedimentary rocks are classified based on the type of sediments used and the resources involved in their formation:

1. On the basis of the sediments used in formation:
In this classification, sedimentary rocks are grouped into Clastic Rocks, Organically Formed Rocks, and Chemically Formed Rocks.

(a) Clastic Rocks: These rocks are formed from rock flour (tiny rock particles) that accumulates in layers after being weathered and eroded. Over time, these layers compact and solidify into sedimentary rocks. Examples include Sandstone and Clay.

(b) Organically Formed Rocks: These rocks are formed from the fossils of living organisms and vegetation. Examples include lime-oriented rocks (like limestone) and carbon-oriented rocks (like coal and dolomite).

(c) Chemically Formed Rocks: These rocks form when chemical substances dissolved in water solidify. This happens as water evaporates or as the speed of water flow decreases, causing dissolved minerals to settle and harden. Examples include Alabaster, Gypsum, and Sart rock.

2. On the basis of the resources used in formation:
Based on the resources involved, sedimentary rocks are classified into three types: Aqueous Rocks, Aeolian Rocks, and Glacial Rocks.

(c) Glacial Rocks: These rocks are formed from pebbles and boulders transported and deposited by glaciers.
In simple words: Sedimentary rocks are made from layers of sediments, fossils, or chemicals. They are categorized by what they're made of (like rock bits, organic matter, or chemical deposits) and by the natural forces that move those materials (like water, wind, or ice).

🎯 Exam Tip: When describing sedimentary rocks, emphasize the layering, accumulation of materials, and the different processes (mechanical, organic, chemical) that lead to their formation. Provide specific examples for each sub-type.

RBSE Class 11 Physical Geography Chapter 6 Other Important Questions

RBSE Class 11 Physical Geography Chapter 6 Multiple Choice Questions

 

Question 1. Which rocks are dominant on the topmost part of the earth?
(a) Igneous
(b) Sedimentary
(c) Metamorphic
(d) None of the options
Answer: (a) Igneous
In simple words: Igneous rocks make up most of the Earth's upper layer because they form directly from cooling molten rock, which is the original material of the crust.

🎯 Exam Tip: Remember that igneous rocks are the primary rocks and form the bulk of the Earth's crust, even if sedimentary rocks cover much of the surface.

 

Question 2. Which type of rock is Granite?
(a) Plutonic Rock
(b) Hypabyssal Rock
(c) Basic Rock
(d) Ultra Basic Rock
Answer: (a) Plutonic Rock
In simple words: Granite is an igneous rock that forms deep inside the Earth when magma cools very slowly, which makes it a plutonic rock.

🎯 Exam Tip: Associate granite with its slow cooling and deep formation, classifying it as a classic example of a plutonic igneous rock.

 

Question 3. Which type of rock is Basalt?
(a) Acidic Rock
(b) Basic Rock
(c) Intermediate Rock
(d) Ultra - Basic Rock
Answer: (b) Basic Rock
In simple words: Basalt is a type of igneous rock with lower silica content, placing it in the category of basic rocks.

🎯 Exam Tip: Understand the chemical classification of igneous rocks (acidic, basic, etc.) by their silica content to correctly identify examples like basalt.

 

Question 5. Which is the lime – oriented rock out of the following?
(a) Granite
(b) Loess
(c) Dolomite
(d) Schist
Answer: (c) Dolomite
In simple words: Dolomite is a sedimentary rock that forms mostly from minerals containing calcium and magnesium, making it a lime-oriented rock.

🎯 Exam Tip: Be familiar with the composition of various sedimentary rocks to identify those rich in lime or other specific minerals.

 

Question 6. The rock formed by the metamorphism of Gabbro is:
(a) Gneiss
(b) Slate
(c) Schist
(d) serpentine
Answer: (d) serpentine
In simple words: When the igneous rock Gabbro undergoes metamorphism, it transforms into serpentine.

🎯 Exam Tip: Learn the specific metamorphic transformations for common igneous rocks like gabbro.

 

Question 7. Diamond is formed by the metamorphism of:
(a) Basalt
(b) Sandstone
(c) Coal
(d) Granite
Answer: (c) Coal
In simple words: Diamond is formed when coal, a sedimentary rock, is subjected to extreme heat and pressure deep within the Earth, undergoing a metamorphic change.

🎯 Exam Tip: The transformation of coal into diamond is a classic example of metamorphism; remember this specific pairing.

Matching Type Questions

 

Question 1. Match Column A with Column B:

Answer:
1. (c) Granite is a Plutonic Rock.
2. (e) Lapolith is a Hypabyssal Rock.
3. (g) Gabbro is a Basic Rock.
4. (f) Peridotite is an Ultra - Basic Rock.
5. (d) Clay is a Clastic Rock.
6. (a) Dolomite is a Lime - oriented Rock.
7. (b) Glacier is associated with Glacial Rock.
In simple words: This matching exercise connects different rock types (like Granite, Gabbro, Dolomite) and geological features (Glacier) to their specific categories or formation processes (Plutonic, Basic, Lime-oriented, Glacial).

🎯 Exam Tip: For matching questions, understand the definition or classification of each term in both columns to make accurate connections.

 

Question 2. Match Column A with Column B:

Answer:
1. (d) Basalt transforms into Amphibolite.
2. (e) Shale transforms into Slate.
3. (a) Sandstone transforms into Quartzite.
4. (b) Schist is a form of Phyllite (Phyllite can further metamorphose into Schist, or Schist is similar in metamorphic grade).
5. (c) Coal transforms into Graphite.
In simple words: This matching activity connects various rock types, showing which original rock transforms into which metamorphic rock. For instance, basalt becomes amphibolite, and coal becomes graphite.

🎯 Exam Tip: These matchings test your knowledge of specific metamorphic transformations. Create a personal flashcard set for these common rock pairs.

RBSE Class 11 Physical Geography Chapter 6 Very Short Answer Type Questions

 

Question 1. What is the upper layer of Earth called?
Answer: The upper layer of Earth is called the Crust (earth surface).
In simple words: The outermost layer of our Earth is known as the Crust.

🎯 Exam Tip: Use the precise geological term "Crust" when referring to the Earth's upper layer.

 

Question 2. How many types of rocks are found?
Answer: Three main types of rocks are found on the earth's surface: igneous rocks, sedimentary rocks, and metamorphic rocks.
In simple words: There are three main kinds of rocks: igneous, sedimentary, and metamorphic.

🎯 Exam Tip: Clearly state the three fundamental types of rocks as these are the basis of rock classification.

 

Question 5. What is Intrusive Igneous Rock?
Answer: Intrusive igneous rocks are those that form when magma cools and hardens beneath the Earth's surface.
In simple words: Intrusive igneous rocks are formed when molten rock cools and solidifies deep underground.

🎯 Exam Tip: The key characteristic of intrusive igneous rocks is their formation *beneath* the Earth's surface from cooling magma.

 

Question 6. What is Plutonic Rock?
Answer: Plutonic rocks are a type of intrusive igneous rock formed when magma cools down and solidifies at a great depth beneath the Earth's surface.
In simple words: Plutonic rocks are igneous rocks that cool and harden very deep inside the Earth.

🎯 Exam Tip: Emphasize "considerable depth" or "great depth" when defining plutonic rocks to differentiate them from other intrusive types.

 

Question 7. What does Hypabyssal Rock mean?
Answer: Hypabyssal rocks are those that form when magma cools and hardens in cracks within other rocks at some depth below the Earth's surface. These rocks usually have small-sized crystals.
In simple words: Hypabyssal rocks are formed when magma cools in cracks inside the Earth, not too deep, and usually have small crystals.

🎯 Exam Tip: Distinguish hypabyssal rocks by their formation in cracks or fissures at *intermediate* depths, linking to their typically smaller crystal size.

 

Question 8. What does Acidic Rock mean?
Answer: Acidic rocks are igneous rocks that contain more than 65% silica. These rocks are typically hard and strong.
In simple words: Acidic rocks are strong, hard igneous rocks that have a lot of silica (more than 65%).

🎯 Exam Tip: The percentage of silica content is the defining characteristic for acidic rocks, so always include it in your answer.

 

Question 9. What does the term Basic Rock mean?
Answer: Basic rocks are igneous rocks in which the amount of silica ranges between 45% to 55%.
In simple words: Basic rocks are igneous rocks with a medium amount of silica, specifically between 45% and 55%.

🎯 Exam Tip: Clearly state the silica percentage range for basic rocks to ensure accuracy.

 

Question 11. Into which categories are the sedimentary rocks classified according to the sediments used?
Answer: According to the sediments used, sedimentary rocks are classified into Clastic Rocks, Organically Formed Rocks, and Chemically Formed Rocks.
In simple words: Sedimentary rocks are grouped based on their components: pieces of other rocks (clastic), remains of living things (organically formed), or chemicals that solidified (chemically formed).

🎯 Exam Tip: Remember the three types of sedimentary rocks based on sediment origin: clastic, organic, and chemical.

 

Question 12. Into which parts are the sedimentary rocks classified according to the resources used in formation?
Answer: According to the resources used in formation, sedimentary rocks are classified into Aqueous Rock, Aeolian Rock, and Glacial Rock.
In simple words: Sedimentary rocks are classified by how they formed: in water (aqueous), by wind (aeolian), or by glaciers (glacial).

🎯 Exam Tip: When classifying sedimentary rocks by formation resources, list the three main categories: aqueous, aeolian, and glacial.

 

Question 13. What is Lime - oriented Rock?
Answer: Rocks that are primarily formed by living organisms dominated by lime (calcium carbonate) are called Lime-oriented Rocks.
In simple words: Lime-oriented rocks are rocks made mostly from the calcium-rich remains of living things.

🎯 Exam Tip: Define lime-oriented rocks by their biological origin and high calcium carbonate content.

 

Question 14. What are Aqueous Rocks?
Answer: Aqueous rocks are sedimentary rocks formed by the deposition of sediments in aquatic environments such as oceans, lakes, and rivers.
In simple words: Aqueous rocks are sedimentary rocks that form when materials settle in water bodies like oceans or lakes.

🎯 Exam Tip: The key feature of aqueous rocks is their formation from sediments deposited in water.

 

Question 15. What does the term Aeolian Rock mean?
Answer: Aeolian rocks are sedimentary rocks formed by the transportation and deposition of particles, such as sand and dust, by wind.
In simple words: Aeolian rocks are sedimentary rocks created by wind picking up and dropping tiny bits of rock.

🎯 Exam Tip: Associate "Aeolian" with wind, as this is the primary agent of transport and deposition for these rocks.

 

Question 16. What is Thermal Metamorphism?
Answer: Thermal metamorphism is the process where igneous and sedimentary rocks change their form, and their mineral grains are reformed due to the effects of extreme heat.
In simple words: Thermal metamorphism happens when rocks change because of very high heat, causing their minerals to rearrange.

🎯 Exam Tip: The defining factor for thermal metamorphism is "extreme heat," which causes mineral changes in existing rocks.

 

Question 11. Into which categories are the sedimentary rocks classified according to the sediments used?
Answer: Sedimentary rocks are grouped into three types based on the sediments used to form them: Clastic Rocks, Organically Formed Rocks, and Chemically Formed Rocks.
In simple words: Sedimentary rocks are divided into three groups based on what kind of material they are made from: broken pieces, remains of living things, or chemical deposits.

🎯 Exam Tip: Remember these three main categories and their distinguishing characteristics for classification questions.

 

Question 12. Into which parts are the sedimentary rocks classified according to the resources used in formation?
Answer: Based on the resources used for their formation, sedimentary rocks are categorized into three types: Aqueous Rock, Aeolian Rock, and Glacial Rock.
In simple words: Sedimentary rocks are sorted into three groups depending on where their materials came from: water, wind, or glaciers.

🎯 Exam Tip: Understanding the source of materials (water, wind, ice) helps differentiate these sedimentary rock types.

 

Question 13. What is Lime - oriented Rock?
Answer: Rocks that are formed mainly from living organisms rich in lime are called Lime-oriented Rocks.
In simple words: Rocks made mostly from the remains of living things that contain a lot of lime are called lime-oriented rocks.

🎯 Exam Tip: Identify "lime-oriented" with biological origins that contain calcium carbonate.

 

Question 14. What are Aqueous Rocks?
Answer: Rocks that are created from sediments deposited in bodies of water, such as rivers or lakes, are known as Aqueous Rocks.
In simple words: Aqueous rocks are formed when materials settle down in water bodies.

🎯 Exam Tip: The word "aqueous" means related to water, so link aqueous rocks to formation in water.

 

Question 15. What does the term Aeolian Rock mean?
Answer: Rocks formed by the movement and settling of particles carried by wind are called Aeolian Rocks.
In simple words: Aeolian rocks are made from sand and dust that the wind carries and drops in one place.

🎯 Exam Tip: Connect "Aeolian" with wind, as aeolian processes involve wind transportation and deposition.

 

Question 16. What is Thermal Metamorphism?
Answer: Thermal metamorphism is the process where igneous and sedimentary rocks change their form, and their minerals rearrange due to extreme heat.
In simple words: When rocks change because of very high heat, it is called thermal metamorphism.

🎯 Exam Tip: The key factor in thermal metamorphism is intense heat causing changes in rock structure.

 

Question 18. What is Thermo - Hydro Metamorphism?
Answer: Thermo-hydro metamorphism is the changes that happen in rocks when hot water, along with pressure and water vapor, interacts with them.
In simple words: This type of metamorphism happens when hot water, steam, and pressure together change rocks.

🎯 Exam Tip: Thermo-hydro metamorphism combines heat ("thermo") and water ("hydro") with pressure to alter rocks.

 

Question 19. Which are the Re - Metamorphic Rocks?
Answer: Re-metamorphic rocks are those that have undergone metamorphism multiple times. For example, slate can transform into schist, and schist can further transform into phyllite.
In simple words: Rocks that change their form more than once due to heat and pressure are called re-metamorphic rocks.

🎯 Exam Tip: Re-metamorphic rocks show a sequence of transformations, like slate to schist to phyllite, indicating multiple metamorphic events.

 

Rbse Class 11 Physical Geography Chapter 6 Short Answer Type Questions (Sa-I)

 

Question 1. Why is the outer layer of earth the important?
Answer: The Earth's outer layer is very important because it contains many valuable elements. Elements like oxygen, silicon, aluminum, iron, calcium, sodium, potassium, magnesium, phosphorus, and sulfur are found here. These elements do not exist separately but usually combine to form different substances. Minerals are the most crucial among these substances.
In simple words: The Earth's outer layer is vital because it holds many important elements and minerals that combine to form various substances.

🎯 Exam Tip: When discussing the importance of the Earth's layers, focus on the abundance of essential elements and minerals found there.

 

Question 2. Why are igneous rocks called the primary rocks?
Answer: Igneous rocks are formed when hot, molten magma and lava cool down and solidify. This happened when the Earth first formed. These rocks were the first to appear, so they are known as Primary Rocks. All other rock types developed from them.
In simple words: Igneous rocks are called primary because they were the first rocks to form directly from cooling magma or lava. All other rocks came from them.

🎯 Exam Tip: Highlight the direct formation from magma/lava and their early appearance as key reasons for igneous rocks being called primary.

 

Question 3. What are the differences between Acidic Rocks and Basic Rocks?
Answer: The following differences are found between Acid Rocks and Basic Rocks:

In simple words: Acidic rocks have more silica and are often harder, while basic rocks have less silica and are generally softer.

🎯 Exam Tip: Focus on the silica content and hardness to distinguish between acidic and basic rocks, and recall that Plutonic and Hypabyssal rocks are types of intrusive igneous rocks, formed at different depths and with different cooling rates affecting their grain size.

 

Question 4. Explain the meaning of Phacolith and Lapolith.
Answer: The meaning of Phacolith and Lapolith is as follows:
1. Phacolith: This is an igneous rock formed when magma solidifies in the folded layers of mountains during a volcanic eruption. It typically has a lens shape.
2. Lapolith: Lapolith comes from the Greek word 'Lekosh', meaning 'water reservoir'. It forms when magma solidifies in a shallow, saucer-shaped basin beneath the Earth's surface.
In simple words: Phacoliths are lens-shaped magma bodies in folded rocks, while Lapoliths are saucer-shaped magma bodies formed in shallow depressions.

🎯 Exam Tip: Remember the distinctive shapes (lens for phacolith, saucer for lapolith) and where they form within folded or shallow rock structures.

 

Question 5. Explain the difference between Sills and Dykes.
Answer: Here are the differences between Sills and Dykes:
1. Sills: These are layers of solidified magma that form horizontally between existing sedimentary rock layers deep within the Earth. Sills are often found in thick forms.
2. Dykes: These are vertical formations of solidified magma that cut across existing rock layers or rock walls deep inside the Earth. Dykes are typically long, thin, and generally hard.
In simple words: Sills are flat sheets of magma that push between rock layers horizontally, while dykes are vertical sheets that cut across rock layers.

🎯 Exam Tip: The key difference between sills and dykes is their orientation: sills are horizontal intrusions, while dykes are vertical intrusions.

 

Question 7. Explain the origin of Metamorphic Rocks.
Answer: Metamorphic rocks originate from existing rocks that undergo significant changes in their properties and structure without completely breaking down. These original rocks can be igneous, sedimentary, or even other metamorphic rocks. This transformation, known as metamorphism, is caused by intense heat, water, and pressure. During metamorphism, not only does the shape of the rocks change, but the structure of their minerals also changes. New minerals can form, and the granular size of the rocks can alter.
In simple words: Metamorphic rocks form when any other rock changes due to high heat, water, and pressure. This changes their shape, structure, and minerals.

🎯 Exam Tip: Emphasize that metamorphic rocks form from existing rocks (igneous, sedimentary, or metamorphic) due to heat, pressure, and chemical changes.

 

Rbse Class 11 Physical Geography Chapter 6 Short Answer Type Questions (Sa-Ii)

 

Question 7. Explain the importance of igneous rocks.
Answer: Igneous rocks are very important because they were the first to form on the Earth's surface. Here are their key contributions:
1. These rocks contain a rich variety of minerals, including valuable ones like gold, silver, zinc, copper, sulfur, and magnesite.
2. They are known as primary rocks because all other rock types have formed from them.
3. The weathering and erosion of igneous rocks contribute to the formation of black soil.
4. Stones and rocks from igneous formations are essential building materials for construction.
5. The fertile soil produced from these rocks is also beneficial for agriculture.
In simple words: Igneous rocks are important because they contain many minerals, are the source of all other rocks, help form fertile black soil, and are used for building.

🎯 Exam Tip: When discussing the importance of igneous rocks, focus on their role as primary rocks, mineral sources, and their contribution to soil formation and construction materials.

 

Question 3. Explain the nature of Clastic Rocks and Chemically Formed Rocks.
Answer:
Clastic Rocks: These rocks are made from rock fragments, or "rock flour," which are produced by weathering and erosion. These fragments accumulate in layers and, over time, compact to form sedimentary rocks. Common examples include sandstone and clay.
Chemically Formed Sedimentary Rocks: These rocks form when various chemical substances dissolve in water. The flowing water carries these dissolved substances, which then accumulate elsewhere and solidify. Examples include alabaster, gypsum, and tufa. These rocks form when dissolved substances settle out of water, either as water evaporates or as its flow slows down, causing the chemicals to precipitate and form new rock.
In simple words: Clastic rocks are made from broken pieces of older rocks, like sand. Chemically formed rocks are made when dissolved chemicals in water settle down and solidify.

🎯 Exam Tip: Distinguish clastic rocks by their fragmented origin and chemically formed rocks by their precipitation from dissolved solutions.

 

Question 5. Explain the importance of Sedimentary and Metamorphic Rocks.
Answer:
Importance of Sedimentary Rocks: Sedimentary rocks are very important for humans. They contain many valuable minerals and energy resources like iron, mineral oil, coal, and natural gas. Hard sandstone, a type of sedimentary rock, is widely used as a building material. Sedimentary rocks also play a role in shaping landscapes and provide historical records through fossils.
Importance of Metamorphic Rocks: After metamorphism, important rocks like marble, graphite, and magnetic iron are formed. These rocks are used for various purposes, including construction, art, and industrial applications. Sulphur-rich water sources found in these rocks are believed to have medicinal properties and can help cure many diseases.
In simple words: Sedimentary rocks are important for energy (like coal and oil) and building materials. Metamorphic rocks are important for valuable materials like marble and graphite, and some hot springs from them are used for health.

🎯 Exam Tip: For importance questions, list both economic uses (minerals, energy, building materials) and other practical/environmental benefits (soil formation, water sources).

 

Question 6. Explain the classification of sedimentary rocks on the basis of the resources used in formation.
Answer: Sedimentary rocks are formed from different kinds of materials, or sediments. These sediments come from various sources. Based on the source of these materials, sedimentary rocks are categorized into the following types:
1. Aqueous Rock: These rocks form from sediments carried and deposited by rivers and other water bodies. They accumulate in aquatic environments like seas, lakes, and riverbeds. Examples include sea rock, lake rock, and river rock.
2. Aeolian Rock: In hot and dry areas, physical weathering breaks down rocks into fine particles. These particles are then transported by wind and deposited elsewhere. As these wind-blown particles rub against each other, they solidify into rocks like Loess.
3. Glacial Rocks: These rocks are formed when glaciers transport and deposit pebbles and boulders. The accumulated material is collectively known as Glacial Drift.
In simple words: Sedimentary rocks are grouped by how their material got there: Aqueous rocks are from water deposits, Aeolian rocks are from wind-blown deposits, and Glacial rocks are from glacier deposits.

🎯 Exam Tip: Clearly link each classification (Aqueous, Aeolian, Glacial) to its respective transportation agent (water, wind, ice).

 

Rbse Class 11 Physical Geography Chapter 6 Essay Type Questions

 

Question 1. Describe in detail the Hypabyssal Rocks formed in the internal part of earth.
Or
Describe the topographies formed by magma in the internal part of earth.
Answer: Hypabyssal rocks are formed when magma solidifies beneath the Earth's surface. A brief description of these rocks and their formations is as follows:
2. Lacolith: Also known as mushroom rock or kukuchail, this term comes from the Greek word 'Lekosh,' meaning 'water reservoir.' It forms when a large body of magma solidifies into a convex, arc-shaped slope with a flat base, typically found in sedimentary rocks.
3. Phacolith: Also called masoor rock, this is a lens-shaped igneous rock. It forms when magma solidifies in the trough-like folds (synclines) of mountains during volcanic eruptions.
4. Lapolith: This refers to a large body of magma that solidifies in a shallow, concave-shaped basin beneath the Earth's surface, creating a saucer-like accumulation called a Lapolith.
5. Sills: Also known as ralapatta, sills are formed when magma cools and solidifies horizontally within the cracks or layers of pre-existing rocks deep inside the Earth. These layers of magma typically form thick, parallel formations.
6. Dykes: Also known as ral bhitti, dykes form when magma solidifies vertically within the cracks or walls of rocks deep inside the Earth. They are long and thin, varying from a few centimeters to hundreds of meters, and are generally hard.
7. Sheet: When magma accumulates horizontally in cracks of rocks in an elongated and thin form, it is called a sheet. These internal Earth topographies are shown with diagrams below.

In simple words: Hypabyssal rocks are intrusive igneous rocks that form when magma cools inside the Earth, creating different shapes like mushroom-shaped lacoliths, lens-shaped phacoliths, saucer-shaped lapoliths, horizontal sills, vertical dykes, and thin sheets.

🎯 Exam Tip: When describing intrusive igneous rock forms, remember to mention both their characteristic shapes and their specific formation environments (e.g., in synclines, between layers, or cutting across layers).

 

Question 2. Explain the types of metamorphism of the Metamorphic Rocks.
Answer: The process of metamorphism in metamorphic rocks is mainly categorized into four types:
2. Dynamic or Regional Metamorphism: This type of metamorphism affects large areas and involves both compression and heat. It often occurs in folded mountain regions, leading to the crystallization of metamorphosed rocks. If the original rock was already crystalline, new crystal formations begin.
3. Hydro Metamorphism: In this process, the minerals in rocks change due to the mixing of chemical substances with water, forming a solution. The presence of excessive water at depth increases both weight and pressure, causing metamorphism in the rocks.
4. Thermo - Hydro Metamorphism: This type of metamorphism occurs when hot water interacts with rocks under pressure and water vapor. Although such metamorphism takes place in certain rocks, it is not as significant geographically.
In simple words: Metamorphism happens in different ways: Dynamic/Regional (large area, heat, compression), Hydro (water and chemical changes), and Thermo-Hydro (hot water, pressure, and vapor).

🎯 Exam Tip: For each type of metamorphism, identify the primary agents involved (heat, pressure, water, chemicals) and their geological context (e.g., mountain building, deep burial).