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All questions of Geomorphology for UPSC CSE Exam
Consider the following statements: 1. Rocks from which minerals are mined are known as ores.2. Kalgoorlie and Coolgardie areas of western Australia have the largest deposits of gold.3. The Katanga Plateau located in the Democratic Republic of Congo(DRC) is known for rich deposits of Copper.Which of the following statement(s) is/are correct?- a) 1 and 2 only
- b) 1 only
- c) 2 and 3 only
- d) 1, 2 and 3
Correct answer is option 'D'. Can you explain this answer?
Consider the following statements:
1. Rocks from which minerals are mined are known as ores.
2. Kalgoorlie and Coolgardie areas of western Australia have the largest deposits of gold.
3. The Katanga Plateau located in the Democratic Republic of Congo(DRC) is known for rich deposits of Copper.
Which of the following statement(s) is/are correct?
a)
1 and 2 only
b)
1 only
c)
2 and 3 only
d)
1, 2 and 3
|
Amit Sharma answered |
- A rock is an aggregate of one or more minerals but without definite composition of constituent minerals. Rocks from which minerals are mined are known as ores.
- Although more than 2,800 types of minerals have been identified, only about 100 are considered ore minerals. The Katanga, or Shaba, Plateau is a farming and ranching region in the Democratic Republic of the Congo.
- Located in the southeastern Katanga Province, it is 1220 m (4,000 ft) above sea level and is rich in copper and uranium deposits. It is the source of the Lufira River, which becomes the Lualaba River.
- Lake Tshangalele, an artificial lake created by a dam on the Lufira, is an important ecological site on the plateau.
Which of the following are not sedimentary rocks? 1. Sandstone2. Limestone3. Marble4. SlateChoose the correct answer using the code below - a) 2 and 3 only
- b) 3 and 4 only
- c) 1 and 4 only
- d) 1 and 3 only
Correct answer is option 'B'. Can you explain this answer?
Which of the following are not sedimentary rocks?
1. Sandstone
2. Limestone
3. Marble
4. Slate
Choose the correct answer using the code below
a)
2 and 3 only
b)
3 and 4 only
c)
1 and 4 only
d)
1 and 3 only
|
|
Arun Khatri answered |
Marble and slate are metamorphic rocks.
The term ‘pole fleeing force’ relates to the- a) Forces responsible for the bulging at the Earth’s poles
- b) Magnetic force as emitted through the poles aligning landforms on Earth
- c) Outward directed forces associated with the spinning of Earth
- d) Forces that causes oscillations in the tilted axis of the Earth
Correct answer is option 'C'. Can you explain this answer?
The term ‘pole fleeing force’ relates to the
a)
Forces responsible for the bulging at the Earth’s poles
b)
Magnetic force as emitted through the poles aligning landforms on Earth
c)
Outward directed forces associated with the spinning of Earth
d)
Forces that causes oscillations in the tilted axis of the Earth
|
Saikat Ghosh answered |
Explanation:
Pole fleeing force is a term used to describe the outward-directed force associated with the spinning of the Earth. This force is also known as centrifugal force. It is the force that causes objects at or near the Earth's equator to experience a slight outward push. This force is due to the rotation of the Earth on its axis.
The centrifugal force is a result of the Earth's rotation, which causes the equator to bulge outwards slightly and the poles to flatten slightly. It is important to note that the pole fleeing force is not responsible for the bulging at the Earth's poles, which is primarily caused by the Earth's rotation and the gravitational pull of the Sun and Moon.
The pole fleeing force is an important factor to consider when studying the Earth's rotation. It influences the Earth's shape, the distribution of mass within the Earth, and the motion of the Earth's oceans and atmosphere.
Conclusion:
In summary, the pole fleeing force is the outward-directed force associated with the spinning of the Earth. It is not responsible for the bulging at the Earth's poles but is an important factor to consider when studying the Earth's rotation.
Pole fleeing force is a term used to describe the outward-directed force associated with the spinning of the Earth. This force is also known as centrifugal force. It is the force that causes objects at or near the Earth's equator to experience a slight outward push. This force is due to the rotation of the Earth on its axis.
The centrifugal force is a result of the Earth's rotation, which causes the equator to bulge outwards slightly and the poles to flatten slightly. It is important to note that the pole fleeing force is not responsible for the bulging at the Earth's poles, which is primarily caused by the Earth's rotation and the gravitational pull of the Sun and Moon.
The pole fleeing force is an important factor to consider when studying the Earth's rotation. It influences the Earth's shape, the distribution of mass within the Earth, and the motion of the Earth's oceans and atmosphere.
Conclusion:
In summary, the pole fleeing force is the outward-directed force associated with the spinning of the Earth. It is not responsible for the bulging at the Earth's poles but is an important factor to consider when studying the Earth's rotation.
Metamorphic rocks are formed due to 1. Cementation of sedimentary rocks2. Proximity of sedimentary rocks with molten magma3. Cooling and solidification of lavaSelect the correct answer using the codes below: - a) 1 only
- b) 2 and 3 only
- c) 2 only
- d) 1 and 2 only
Correct answer is option 'C'. Can you explain this answer?
Metamorphic rocks are formed due to
1. Cementation of sedimentary rocks
2. Proximity of sedimentary rocks with molten magma
3. Cooling and solidification of lava
Select the correct answer using the codes below:
a)
1 only
b)
2 and 3 only
c)
2 only
d)
1 and 2 only
|
Ravi Sharma answered |
- Metamorphic rocks are made by either heating up or squashing the Earth’s crust. They are often found in mountainous regions. One example is slate. Slate was originally a black mud laid down on the bottom of the sea or lake.
- Sometimes, metamorphic rocks are formed when rocks are close to some molten magma, and so get heated up. When metamorphic rock is formed under pressure, its crystals become arranged in layers. Slate, which is formed from shale, is like this. Slate is useful for making roof tiles because its layers can be split into separate flat sheets.
Consider the following statements about earthquakes:
1. The point where the energy is released is called the focus.
2. The point on the surface, nearest to the focus, is called the epicentre.
Which of the above statements is/are correct?
- a)1 only
- b)2 only
- c)Both 1 and 2
- d)None of these
Correct answer is option 'C'. Can you explain this answer?
Consider the following statements about earthquakes:
1. The point where the energy is released is called the focus.
2. The point on the surface, nearest to the focus, is called the epicentre.
Which of the above statements is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of these
|
Sumit Kumar answered |
The question is asking about the incorrect statement but here both statement are correct so the option (D) is correct.
Most volcanoes and earthquakes in the world arc located at - a) Littoral zones of major oceans
- b) Within the plates
- c) The inter-junction of major mountains of the world
- d) Plate margins
Correct answer is option 'D'. Can you explain this answer?
Most volcanoes and earthquakes in the world arc located at
a)
Littoral zones of major oceans
b)
Within the plates
c)
The inter-junction of major mountains of the world
d)
Plate margins
|
Saikat Datta answered |
Explanation:
Volcanoes and earthquakes are natural phenomena that occur due to the movement of tectonic plates. These plates make up the Earth's crust and are constantly shifting and colliding with each other. The majority of volcanoes and earthquakes in the world are located at plate margins.
Plate Margins:
Plate margins are the boundaries where two tectonic plates meet. There are three main types of plate boundaries:
1. Divergent Boundaries: This is where two plates move away from each other. This movement creates a gap between the two plates which magma rises up to fill, creating new crust. This is where most of the world's volcanoes are located.
2. Convergent Boundaries: This is where two plates move towards each other. This movement can cause one plate to be forced under the other, creating a subduction zone. This can cause earthquakes and volcanic eruptions.
3. Transform Boundaries: This is where two plates slide past each other horizontally. This can cause earthquakes but rarely causes volcanic eruptions.
Conclusion:
In conclusion, the majority of volcanoes and earthquakes in the world are located at plate margins. The movement of tectonic plates at these boundaries causes geological activity such as volcanic eruptions and earthquakes. Understanding plate tectonics and plate boundaries is important for predicting and mitigating the risks associated with these natural phenomena.
Volcanoes and earthquakes are natural phenomena that occur due to the movement of tectonic plates. These plates make up the Earth's crust and are constantly shifting and colliding with each other. The majority of volcanoes and earthquakes in the world are located at plate margins.
Plate Margins:
Plate margins are the boundaries where two tectonic plates meet. There are three main types of plate boundaries:
1. Divergent Boundaries: This is where two plates move away from each other. This movement creates a gap between the two plates which magma rises up to fill, creating new crust. This is where most of the world's volcanoes are located.
2. Convergent Boundaries: This is where two plates move towards each other. This movement can cause one plate to be forced under the other, creating a subduction zone. This can cause earthquakes and volcanic eruptions.
3. Transform Boundaries: This is where two plates slide past each other horizontally. This can cause earthquakes but rarely causes volcanic eruptions.
Conclusion:
In conclusion, the majority of volcanoes and earthquakes in the world are located at plate margins. The movement of tectonic plates at these boundaries causes geological activity such as volcanic eruptions and earthquakes. Understanding plate tectonics and plate boundaries is important for predicting and mitigating the risks associated with these natural phenomena.
The oldest rocks in the world can be found in which of these regions? - a) Western Australia
- b) Southern Europe
- c) North America
- d) Eastern Asia
Correct answer is option 'A'. Can you explain this answer?
The oldest rocks in the world can be found in which of these regions?
a)
Western Australia
b)
Southern Europe
c)
North America
d)
Eastern Asia
|
Srestha Deshpande answered |
Oldest Rocks in the World
The oldest rocks in the world are found in Western Australia.
Evidence
- The rocks in Western Australia are known as the Jack Hills group and have been dated to be 4.4 billion years old.
- These rocks were formed during the Hadean Eon, which lasted from the formation of the Earth around 4.6 billion years ago to the beginning of the Archean Eon around 4 billion years ago.
- The rocks contain tiny zircon crystals which have been used to determine their age.
- The zircon crystals have been found to be up to 4.4 billion years old, making them the oldest known rocks in the world.
Importance
- The discovery of these rocks in Western Australia has important implications for our understanding of the early Earth.
- It suggests that the planet was able to cool and solidify much faster than previously thought.
- It also suggests that conditions on the early Earth were more hospitable for life than previously thought, as life is believed to have emerged around 3.5 billion years ago.
Conclusion
In conclusion, the oldest rocks in the world are found in Western Australia and are known as the Jack Hills group. These rocks have been dated to be 4.4 billion years old and contain tiny zircon crystals which have been used to determine their age. The discovery of these rocks has important implications for our understanding of the early Earth and the emergence of life.
The oldest rocks in the world are found in Western Australia.
Evidence
- The rocks in Western Australia are known as the Jack Hills group and have been dated to be 4.4 billion years old.
- These rocks were formed during the Hadean Eon, which lasted from the formation of the Earth around 4.6 billion years ago to the beginning of the Archean Eon around 4 billion years ago.
- The rocks contain tiny zircon crystals which have been used to determine their age.
- The zircon crystals have been found to be up to 4.4 billion years old, making them the oldest known rocks in the world.
Importance
- The discovery of these rocks in Western Australia has important implications for our understanding of the early Earth.
- It suggests that the planet was able to cool and solidify much faster than previously thought.
- It also suggests that conditions on the early Earth were more hospitable for life than previously thought, as life is believed to have emerged around 3.5 billion years ago.
Conclusion
In conclusion, the oldest rocks in the world are found in Western Australia and are known as the Jack Hills group. These rocks have been dated to be 4.4 billion years old and contain tiny zircon crystals which have been used to determine their age. The discovery of these rocks has important implications for our understanding of the early Earth and the emergence of life.
Which of the following evidence supports the hypothesis of ‘seafloor spreading’?1. Rocks on either side of mid-oceanic ridges have remarkable similarities.2. Earthquake foci at mid-oceanic ridges are shallower than oceanic trenches.3. Oceanic crust rocks arc younger than continental rock crust.Choose the correct answer using the codes below: - a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Which of the following evidence supports the hypothesis of ‘seafloor spreading’?
1. Rocks on either side of mid-oceanic ridges have remarkable similarities.
2. Earthquake foci at mid-oceanic ridges are shallower than oceanic trenches.
3. Oceanic crust rocks arc younger than continental rock crust.
Choose the correct answer using the codes below:
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
Poonam Reddy answered |
- Mapping of the ocean floor a paleomagnetic rock studies of ocean regions disclosed the below facts:
(i) Volcanic eruptions are common in the mid-oceanic ridges, and enormous amounts of lava were brought to the surface by these eruptions.
(ii) There are striking similarities formation, chemical composition and magnetic properties between the rocks that are present equidistant on either side of the crest of mid-oceanic ridges.
(iii) The continental rocks are older than the ocean crust rocks. The oceanic crust rocks’ age is not more than 200 million years and some continental rocks are older than 3,200 million years.
(iv)The deep trenches have deep-seated earthquake occurrences while in the mid-oceanic ridge areas, the quake foci have shallow depths. It means lava is in close vicinity.
Exfoliation refers to - a) Carrying away of topsoil layer by the wind in deserts
- b) Peeling of rock layers because of the weathering process
- c) Cracking of rocks into small pieces in deserts
- d) None of the above
Correct answer is option 'B'. Can you explain this answer?
Exfoliation refers to
a)
Carrying away of topsoil layer by the wind in deserts
b)
Peeling of rock layers because of the weathering process
c)
Cracking of rocks into small pieces in deserts
d)
None of the above
|
|
Suresh Reddy answered |
Exfoliation is the separation of successive thin shells, or spalls, from massive rock such as granite or basalt; it is common in regions that have moderate rainfall. The thickness of an individual sheet or plate may be from a few millimetres to a few metres.
Regarding river capture, consider the following statements: 1. It is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream.2. It is also called river beheading.3. Apart from tectonic Earth movements, erosion also results in river capture.Which of the above is/are correct? - a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Regarding river capture, consider the following statements:
1. It is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed, and flows instead down the bed of a neighbouring stream.
2. It is also called river beheading.
3. Apart from tectonic Earth movements, erosion also results in river capture.
Which of the above is/are correct?
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
|
Disha Ahuja answered |
Overview:
River capture is a geomorphological process in which a stream or river drainage system is diverted from its own bed and flows instead down the bed of a neighboring stream. It is also known as river beheading and can occur due to tectonic Earth movements or erosion.
Explanation:
The given statements are as follows:
Statement 1: It is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed and flows instead down the bed of a neighboring stream.
This statement is correct. River capture is a natural process where water from one river or stream is diverted to flow into another river or stream. This can happen due to various factors such as changes in the landscape, erosion, or tectonic activities. When a river captures another, it usually occurs at a point where the two river systems are close to each other and the water can easily flow from one to another.
Statement 2: It is also called river beheading.
This statement is correct. River capture is also known as river beheading because one river captures the drainage of another river, leading to the diversion of water flow.
Statement 3: Apart from tectonic Earth movements, erosion also results in river capture.
This statement is correct. River capture can occur due to both tectonic Earth movements and erosion. Tectonic movements, such as the uplift of land or the creation of a new fault line, can alter the landscape and cause changes in the drainage patterns of rivers. Erosion, on the other hand, can occur due to the wearing away of the land by the force of the flowing water, leading to changes in the river courses and potential river capture.
Conclusion:
In conclusion, all the given statements are correct. River capture is a geomorphological phenomenon that can occur due to tectonic Earth movements or erosion. It involves the diversion of a river or stream from its own bed to flow down the bed of a neighboring stream.
River capture is a geomorphological process in which a stream or river drainage system is diverted from its own bed and flows instead down the bed of a neighboring stream. It is also known as river beheading and can occur due to tectonic Earth movements or erosion.
Explanation:
The given statements are as follows:
Statement 1: It is a geomorphological phenomenon occurring when a stream or river drainage system or watershed is diverted from its own bed and flows instead down the bed of a neighboring stream.
This statement is correct. River capture is a natural process where water from one river or stream is diverted to flow into another river or stream. This can happen due to various factors such as changes in the landscape, erosion, or tectonic activities. When a river captures another, it usually occurs at a point where the two river systems are close to each other and the water can easily flow from one to another.
Statement 2: It is also called river beheading.
This statement is correct. River capture is also known as river beheading because one river captures the drainage of another river, leading to the diversion of water flow.
Statement 3: Apart from tectonic Earth movements, erosion also results in river capture.
This statement is correct. River capture can occur due to both tectonic Earth movements and erosion. Tectonic movements, such as the uplift of land or the creation of a new fault line, can alter the landscape and cause changes in the drainage patterns of rivers. Erosion, on the other hand, can occur due to the wearing away of the land by the force of the flowing water, leading to changes in the river courses and potential river capture.
Conclusion:
In conclusion, all the given statements are correct. River capture is a geomorphological phenomenon that can occur due to tectonic Earth movements or erosion. It involves the diversion of a river or stream from its own bed to flow down the bed of a neighboring stream.
Texturally mature sediment is usually well rounded and well-sorted due to:1. Rounding of sediment increases with transport distance and time.2. Sorting gets better as larger chunks arc left behind and smaller chunks arc carried away.Which of the above statements is/are correct? - a) 1 only
- b) 2 only
- c) Both 1 and 2
- d) None of the above
Correct answer is option 'C'. Can you explain this answer?
Texturally mature sediment is usually well rounded and well-sorted due to:
1. Rounding of sediment increases with transport distance and time.
2. Sorting gets better as larger chunks arc left behind and smaller chunks arc carried away.
Which of the above statements is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of the above
|
Kabir Verma answered |
- Sediment maturity refers to the length of time that the sediment has become in the sedimentary cycle.
- Texturally mature sediment is sediment that is well rounded (as rounding increases with transport distance and time) and well sorted (as sorting gets better as larger clasts are left behind and smaller clasts arc carried away).
- If the fragments arc angular, it indicates that they have not been transported very far and the sediment is poorly sorted.
Regarding the distribution of volcanoes around the world, consider the following statements: 1. The Atlantic coasts have many active volcanoes.2. The Pacific Ocean has the highest number of active volcanoes in its coasts thanks to folded and faulted Landforms.Which of the above is/are correct? - a) 1 only
- b) 2 only
- c) Both 1 and 2
- d) None of the above
Correct answer is option 'B'. Can you explain this answer?
Regarding the distribution of volcanoes around the world, consider the following statements:
1. The Atlantic coasts have many active volcanoes.
2. The Pacific Ocean has the highest number of active volcanoes in its coasts thanks to folded and faulted Landforms.
Which of the above is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of the above
|
|
Kabir Verma answered |
- Atlantic coasts have very few volcanoes and that too dormant ones.
- The Pacific Ocean has many volcanoes due to its activeness in volcanic eruptions called the Ring of Fire.
Consider the following statements about rocks: 1. Igneous rocks arc also called as primary rocks.2. Igneous and sedimentary rocks can change into metamorphic rocks under great heat and pressure.3. Sandstone is a metamorphic rock.Which of the above statements is/are correct? - a) 1 and 2 only
- b) 1 and 3 only
- c) 2 and 3 only
- d) 2 only
Correct answer is option 'A'. Can you explain this answer?
Consider the following statements about rocks:
1. Igneous rocks arc also called as primary rocks.
2. Igneous and sedimentary rocks can change into metamorphic rocks under great heat and pressure.
3. Sandstone is a metamorphic rock.
Which of the above statements is/are correct?
a)
1 and 2 only
b)
1 and 3 only
c)
2 and 3 only
d)
2 only
|
Sagarika Desai answered |
Sandstone is a sedimentary rock formed by sedimentation of sand grains.
Which of the following are the salient features of fold Mountains? 1. They are least likely to have conical peaks.2. They are created when large areas are broken and displaced vertically.3. They must be associated with volcanism either from the mountain core or its vicinity.Which of the above statement(s) is/are correct? - a) 1 and 3 only
- b) 2 only
- c) All of the above
- d) None of the above
Correct answer is option 'D'. Can you explain this answer?
Which of the following are the salient features of fold Mountains?
1. They are least likely to have conical peaks.
2. They are created when large areas are broken and displaced vertically.
3. They must be associated with volcanism either from the mountain core or its vicinity.
Which of the above statement(s) is/are correct?
a)
1 and 3 only
b)
2 only
c)
All of the above
d)
None of the above
|
|
Megha Kumar answered |
Salient Features of Fold Mountains
Fold mountains are formed by the folding of the Earth's crust. They are characterized by certain salient features, which are discussed below.
1. Conical Peaks:
Fold mountains are most likely to have conical peaks due to the volcanic activity associated with them. The magma below the surface rises and solidifies to form a cone-shaped structure.
2. Vertical Displacement:
Fold mountains are created when large areas of the Earth's crust are broken and displaced vertically, leading to the formation of fold structures.
3. Associated Volcanism:
Fold mountains are often associated with volcanism, either from the mountain core or its vicinity. This is due to the movement of tectonic plates, which leads to the formation of magma chambers and volcanic eruptions.
Correct Option
None of the above statements is correct as the first statement is incorrect. Fold mountains are most likely to have conical peaks due to the associated volcanic activity.
Fold mountains are formed by the folding of the Earth's crust. They are characterized by certain salient features, which are discussed below.
1. Conical Peaks:
Fold mountains are most likely to have conical peaks due to the volcanic activity associated with them. The magma below the surface rises and solidifies to form a cone-shaped structure.
2. Vertical Displacement:
Fold mountains are created when large areas of the Earth's crust are broken and displaced vertically, leading to the formation of fold structures.
3. Associated Volcanism:
Fold mountains are often associated with volcanism, either from the mountain core or its vicinity. This is due to the movement of tectonic plates, which leads to the formation of magma chambers and volcanic eruptions.
Correct Option
None of the above statements is correct as the first statement is incorrect. Fold mountains are most likely to have conical peaks due to the associated volcanic activity.
The ‘Pacific Ring of Fire’ is a chain of volcanoes and includes locations from1. New Zealand2. Alaska3. Pacific islands of SolomonWhich of the above is/are correct? - a)1 and 2 only
- b)2 and 3 only
- c)1 and 3 only
- d)All of the above
Correct answer is option 'D'. Can you explain this answer?
The ‘Pacific Ring of Fire’ is a chain of volcanoes and includes locations from
1. New Zealand
2. Alaska
3. Pacific islands of Solomon
Which of the above is/are correct?
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
|
Alok Verma answered |
- The Ring of Fire stretches from the southern tip of South America, up along the coast of North America, across the Bering Strait, down through Japan, and into New Zealand. Sri Lanka lies outside the ring.
- The southern portion is more complex, with several smaller tectonic plates in collision with the Pacific plate from the Mariana Islands, the Philippines, Bougainville, Tonga etc.
Regarding fold mountains, consider the following statements: 1. Alpine mountain building phase is the recent phase to which the Himalayan mountains belong to.2. The Ural Mountains were formed during Alpine orogeny (mountain building phase) too.Which of the above statement(s) is/are correct? - a) 1 only
- b) 2 only
- c) Both 1 and 2
- d) None of the above
Correct answer is option 'A'. Can you explain this answer?
Regarding fold mountains, consider the following statements:
1. Alpine mountain building phase is the recent phase to which the Himalayan mountains belong to.
2. The Ural Mountains were formed during Alpine orogeny (mountain building phase) too.
Which of the above statement(s) is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of the above
|
|
Arindam Mukherjee answered |
Explanation:
Alpine mountain building phase is the recent phase to which the Himalayan mountains belong to. The Ural Mountains were not formed during the Alpine orogeny (mountain building phase).
Therefore, the correct answer is option 'A' - 1 only.
- Alpine Mountain Building Phase
The Alpine mountain building phase is the most recent phase and began about 40 million years ago. This phase is ongoing and still forming mountains today in areas such as the Himalayas, the Alps, and the Andes.
- Himalayan Mountains
The Himalayan Mountains are a range of fold mountains located in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. They were formed during the ongoing Alpine mountain building phase.
- Ural Mountains
The Ural Mountains are a range of fold mountains located in western Russia, separating Europe and Asia. They were formed during the Variscan orogeny, which occurred about 300 million years ago, and not during the Alpine mountain building phase.
Therefore, statement 1 is correct, and statement 2 is incorrect.
Alpine mountain building phase is the recent phase to which the Himalayan mountains belong to. The Ural Mountains were not formed during the Alpine orogeny (mountain building phase).
Therefore, the correct answer is option 'A' - 1 only.
- Alpine Mountain Building Phase
The Alpine mountain building phase is the most recent phase and began about 40 million years ago. This phase is ongoing and still forming mountains today in areas such as the Himalayas, the Alps, and the Andes.
- Himalayan Mountains
The Himalayan Mountains are a range of fold mountains located in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. They were formed during the ongoing Alpine mountain building phase.
- Ural Mountains
The Ural Mountains are a range of fold mountains located in western Russia, separating Europe and Asia. They were formed during the Variscan orogeny, which occurred about 300 million years ago, and not during the Alpine mountain building phase.
Therefore, statement 1 is correct, and statement 2 is incorrect.
Concerning desert landforms, consider the following statements:1. Mesa and Butte are table-like land masses with very resistant horizontal top layers and steep slope.2. Zeugen are isolated residual round hills found in the desert.Which of the above is/are correct? - a) 1 only
- b) 2 only
- c) Both 1 and 2
- d) None of the above
Correct answer is option 'A'. Can you explain this answer?
Concerning desert landforms, consider the following statements:
1. Mesa and Butte are table-like land masses with very resistant horizontal top layers and steep slope.
2. Zeugen are isolated residual round hills found in the desert.
Which of the above is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of the above
|
|
Mihir Mehta answered |
Explanation:
The correct answer is option 'A' (1 only).
1. Mesa and Butte:
- Mesas and buttes are table-like land masses found in desert regions.
- They are characterized by their very resistant horizontal top layers and steep slopes.
- These landforms are formed due to the differential erosion of sedimentary rock layers.
- The hard and resistant top layer protects the softer layers underneath from erosion.
- Over time, the softer layers erode away, leaving behind the resistant top layer, which forms a flat-topped mesa or butte.
- The steep slopes of mesas and buttes are often referred to as "scarps" and can be several hundred meters high.
- These landforms are commonly found in arid regions, including deserts.
2. Zeugen:
- Zeugen are not isolated residual round hills found in the desert.
- Zeugen are actually elongated ridges or hills that are formed as a result of erosion.
- They are typically found in areas where there are horizontal layers of rock with alternating hard and soft layers.
- The soft layers erode more quickly, leaving behind the hard layers, which form the elongated ridges or hills.
- Zeugen are not exclusive to desert regions and can be found in various landscapes.
In conclusion, statement 1 is correct as mesas and buttes are table-like land masses with very resistant horizontal top layers and steep slopes. However, statement 2 is incorrect as zeugen are not isolated residual round hills found in the desert.
Which of the following processes contributes to the enrichment of minerals in rocks?- a) Weathering of rocks
- b) Erosional and depositional action of rivers
- c) Both (a) and (b)
- d) None of the above
Correct answer is option 'C'. Can you explain this answer?
Which of the following processes contributes to the enrichment of minerals in rocks?
a)
Weathering of rocks
b)
Erosional and depositional action of rivers
c)
Both (a) and (b)
d)
None of the above
|
|
Madhurima Tiwari answered |
Weathering of rocks:
- Weathering is the process by which rocks are broken down into smaller pieces or undergo chemical changes due to exposure to various environmental factors such as wind, water, and temperature changes.
- As rocks undergo weathering, the minerals present in them are released and become available for other processes to act upon.
- This weathering process can be physical, such as the freezing and thawing of water in cracks, or chemical, such as the reaction of rock minerals with water or acids.
- The weathering of rocks plays a significant role in the enrichment of minerals in rocks because it breaks down the rock into smaller particles, exposing more surface area for chemical reactions to occur.
Erosional and depositional action of rivers:
- Rivers play a crucial role in the transportation and deposition of sediments.
- As rivers flow, they erode the land, carrying sediments such as rocks, minerals, and soil particles.
- These sediments are transported downstream and eventually deposited when the river's velocity decreases, such as in river bends or at the mouth of the river.
- During this process, minerals that were weathered from rocks in the upstream areas are carried by the river and deposited in new locations.
- The erosional and depositional action of rivers helps in redistributing and concentrating minerals, thereby contributing to the enrichment of minerals in rocks.
Both (a) and (b):
- Both weathering of rocks and the erosional and depositional action of rivers contribute to the enrichment of minerals in rocks.
- Weathering breaks down rocks, releasing minerals and making them available for other processes.
- Rivers then transport these minerals and deposit them in new locations, contributing to the enrichment of minerals in rocks.
- The combined action of weathering and rivers helps in the concentration and redistribution of minerals, ultimately leading to the enrichment of minerals in rocks.
Therefore, the correct answer is option 'C' - Both (a) and (b).
- Weathering is the process by which rocks are broken down into smaller pieces or undergo chemical changes due to exposure to various environmental factors such as wind, water, and temperature changes.
- As rocks undergo weathering, the minerals present in them are released and become available for other processes to act upon.
- This weathering process can be physical, such as the freezing and thawing of water in cracks, or chemical, such as the reaction of rock minerals with water or acids.
- The weathering of rocks plays a significant role in the enrichment of minerals in rocks because it breaks down the rock into smaller particles, exposing more surface area for chemical reactions to occur.
Erosional and depositional action of rivers:
- Rivers play a crucial role in the transportation and deposition of sediments.
- As rivers flow, they erode the land, carrying sediments such as rocks, minerals, and soil particles.
- These sediments are transported downstream and eventually deposited when the river's velocity decreases, such as in river bends or at the mouth of the river.
- During this process, minerals that were weathered from rocks in the upstream areas are carried by the river and deposited in new locations.
- The erosional and depositional action of rivers helps in redistributing and concentrating minerals, thereby contributing to the enrichment of minerals in rocks.
Both (a) and (b):
- Both weathering of rocks and the erosional and depositional action of rivers contribute to the enrichment of minerals in rocks.
- Weathering breaks down rocks, releasing minerals and making them available for other processes.
- Rivers then transport these minerals and deposit them in new locations, contributing to the enrichment of minerals in rocks.
- The combined action of weathering and rivers helps in the concentration and redistribution of minerals, ultimately leading to the enrichment of minerals in rocks.
Therefore, the correct answer is option 'C' - Both (a) and (b).
Which o f these geographical features is most likely to have the lowest mean elevation?- a) Plateaus
- b) Islands
- c) Deltas
- d) Plains
Correct answer is option 'C'. Can you explain this answer?
Which o f these geographical features is most likely to have the lowest mean elevation?
a)
Plateaus
b)
Islands
c)
Deltas
d)
Plains
|
|
Kirti Pillai answered |
Deltas are most likely to have the lowest mean elevation among the given options.
Explanation:
Deltas are formed at the mouth of a river where it meets an ocean, sea, lake, or another river. They are created by the accumulation of sediments, such as sand, silt, and clay, that are carried by the river and deposited at its mouth. Over time, these sediments build up and form a triangular or fan-shaped landform.
There are several reasons why deltas tend to have lower mean elevation compared to other geographical features:
1. Deposition of sediments: Deltas are primarily formed through the deposition of sediments carried by the river. These sediments are often fine-grained and easily settle at the mouth of the river, leading to the accumulation of sediment layers. As a result, the delta gradually builds up over time, which can cause the land to be relatively flat and low-lying.
2. Flattening effect of water: The flowing water at the mouth of the river tends to spread out and slow down, which reduces its erosive power. This allows the sediments to settle and accumulate more easily, contributing to the formation of a delta. The water's flattening effect also contributes to the relatively low elevation of deltas.
3. Subsidence: Deltas are often located in areas where subsidence occurs. Subsidence is the sinking of the land due to various factors such as tectonic activity, sediment compaction, and groundwater extraction. When the land subsides, the delta may sink further, resulting in a lower mean elevation.
4. Proximity to bodies of water: Deltas are typically found at the mouths of rivers where they meet large bodies of water. The proximity to these bodies of water, such as oceans or lakes, means that the delta is influenced by tidal movements and wave action. These forces can erode the delta's landforms and contribute to its relatively low elevation.
In conclusion, deltas are most likely to have the lowest mean elevation among the given options due to the deposition of sediments, the flattening effect of water, subsidence, and the proximity to bodies of water.
Explanation:
Deltas are formed at the mouth of a river where it meets an ocean, sea, lake, or another river. They are created by the accumulation of sediments, such as sand, silt, and clay, that are carried by the river and deposited at its mouth. Over time, these sediments build up and form a triangular or fan-shaped landform.
There are several reasons why deltas tend to have lower mean elevation compared to other geographical features:
1. Deposition of sediments: Deltas are primarily formed through the deposition of sediments carried by the river. These sediments are often fine-grained and easily settle at the mouth of the river, leading to the accumulation of sediment layers. As a result, the delta gradually builds up over time, which can cause the land to be relatively flat and low-lying.
2. Flattening effect of water: The flowing water at the mouth of the river tends to spread out and slow down, which reduces its erosive power. This allows the sediments to settle and accumulate more easily, contributing to the formation of a delta. The water's flattening effect also contributes to the relatively low elevation of deltas.
3. Subsidence: Deltas are often located in areas where subsidence occurs. Subsidence is the sinking of the land due to various factors such as tectonic activity, sediment compaction, and groundwater extraction. When the land subsides, the delta may sink further, resulting in a lower mean elevation.
4. Proximity to bodies of water: Deltas are typically found at the mouths of rivers where they meet large bodies of water. The proximity to these bodies of water, such as oceans or lakes, means that the delta is influenced by tidal movements and wave action. These forces can erode the delta's landforms and contribute to its relatively low elevation.
In conclusion, deltas are most likely to have the lowest mean elevation among the given options due to the deposition of sediments, the flattening effect of water, subsidence, and the proximity to bodies of water.
Despite such a large geographical spread, why is the Himalayan region poor in mineral resources? - a) The terrain is undulating,
- b) The rock structure is complex.
- c) The climatic conditions are adverse.
- d) It is made up of crystalline rocks which do not hold mineral resources anywhere in India.
Correct answer is option 'B'. Can you explain this answer?
Despite such a large geographical spread, why is the Himalayan region poor in mineral resources?
a)
The terrain is undulating,
b)
The rock structure is complex.
c)
The climatic conditions are adverse.
d)
It is made up of crystalline rocks which do not hold mineral resources anywhere in India.
|
|
Prasad Shah answered |
Himalayan region and its poor mineral resources
There are several factors that contribute to the Himalayan region being poor in mineral resources. However, the most significant reason is the complex rock structure in the region.
Complex rock structure
The Himalayan region is characterized by a complex geological history, resulting in the formation of diverse rock types and structures. The region is mainly composed of metamorphic and sedimentary rocks, which are less likely to contain significant mineral deposits compared to other types of rocks such as igneous rocks. Metamorphic rocks are formed through the transformation of pre-existing rocks under high pressure and temperature conditions, which often leads to the loss of mineral resources.
Unfavorable terrain and adverse climatic conditions
While the undulating terrain and adverse climatic conditions in the Himalayan region certainly pose challenges for mineral exploration and extraction, they are not the primary reasons for the region's poor mineral resources. These factors may make it difficult to access certain areas and conduct mining operations, but they do not directly impact the presence or absence of mineral resources in the region.
Crystalline rocks and mineral resources
The statement mentioned that the Himalayan region is made up of crystalline rocks, which do not hold mineral resources anywhere in India. This is incorrect. Crystalline rocks can indeed contain mineral resources, although their presence and abundance vary from region to region. Crystalline rocks, such as granite and gneiss, can host valuable minerals such as gold, silver, copper, and tin. However, in the case of the Himalayan region, the primary reason for the lack of mineral resources is the complex rock structure rather than the presence of crystalline rocks.
In conclusion, the Himalayan region's poor mineral resources can be attributed to its complex rock structure, which is dominated by metamorphic and sedimentary rocks. While other factors such as unfavorable terrain and adverse climatic conditions might pose challenges for mineral extraction, they are not the main reasons for the region's limited mineral resources.
There are several factors that contribute to the Himalayan region being poor in mineral resources. However, the most significant reason is the complex rock structure in the region.
Complex rock structure
The Himalayan region is characterized by a complex geological history, resulting in the formation of diverse rock types and structures. The region is mainly composed of metamorphic and sedimentary rocks, which are less likely to contain significant mineral deposits compared to other types of rocks such as igneous rocks. Metamorphic rocks are formed through the transformation of pre-existing rocks under high pressure and temperature conditions, which often leads to the loss of mineral resources.
Unfavorable terrain and adverse climatic conditions
While the undulating terrain and adverse climatic conditions in the Himalayan region certainly pose challenges for mineral exploration and extraction, they are not the primary reasons for the region's poor mineral resources. These factors may make it difficult to access certain areas and conduct mining operations, but they do not directly impact the presence or absence of mineral resources in the region.
Crystalline rocks and mineral resources
The statement mentioned that the Himalayan region is made up of crystalline rocks, which do not hold mineral resources anywhere in India. This is incorrect. Crystalline rocks can indeed contain mineral resources, although their presence and abundance vary from region to region. Crystalline rocks, such as granite and gneiss, can host valuable minerals such as gold, silver, copper, and tin. However, in the case of the Himalayan region, the primary reason for the lack of mineral resources is the complex rock structure rather than the presence of crystalline rocks.
In conclusion, the Himalayan region's poor mineral resources can be attributed to its complex rock structure, which is dominated by metamorphic and sedimentary rocks. While other factors such as unfavorable terrain and adverse climatic conditions might pose challenges for mineral extraction, they are not the main reasons for the region's limited mineral resources.
Consider the following features in a drainage system: 1. Interlocking spurs2. Meanders3. River cliffs4. Rapids and waterfallsWhich of the above will be found in the middle course of the river system? - a) 1 and 2 only
- b) 2 and 3 only
- c) 3 and 4 only
- d) 1, 2 and 3 only
Correct answer is option 'D'. Can you explain this answer?
Consider the following features in a drainage system:
1. Interlocking spurs
2. Meanders
3. River cliffs
4. Rapids and waterfalls
Which of the above will be found in the middle course of the river system?
a)
1 and 2 only
b)
2 and 3 only
c)
3 and 4 only
d)
1, 2 and 3 only
|
|
Anuj Kumar answered |
Upper course river features include steep-sided V-shaped valleys, interlocking spurs, rapids, waterfalls and gorges. Middle course river features include wider, shallower valleys, meanders, and oxbow lakes.
Lagoon is 1. Fresh-water lake2. Separated from the sea by sandbars and spits3. Considered similar to some of the estuariesChoose the correct answer using the codes below: - a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'B'. Can you explain this answer?
Lagoon is
1. Fresh-water lake
2. Separated from the sea by sandbars and spits
3. Considered similar to some of the estuaries
Choose the correct answer using the codes below:
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
|
Mahi Khanna answered |
Explanation:
In this question, we are given three statements about lagoons and we need to choose the correct answer using the given options.
Statement 1: Lagoon is a fresh-water lake.
Statement 2: Lagoon is separated from the sea by sandbars and spits.
Statement 3: Lagoon is considered similar to some of the estuaries.
To determine the correct answer, let's analyze each statement.
Statement 1: Lagoon is a fresh-water lake.
A lagoon is not necessarily a fresh-water lake. It can be either fresh or saltwater, depending on its location and connection to the sea. Therefore, this statement is incorrect.
Statement 2: Lagoon is separated from the sea by sandbars and spits.
This statement is true. A lagoon is a shallow body of water separated from the sea by sandbars, spits, or barrier islands. These natural formations act as a barrier, creating a calm and sheltered environment within the lagoon.
Statement 3: Lagoon is considered similar to some of the estuaries.
This statement is also true. Lagoons and estuaries share some similarities. Both are partially enclosed bodies of water connected to the sea. However, there are some differences as well. Lagoons are typically separated from the sea by sandbars or spits, while estuaries are formed at the mouths of rivers and are influenced by freshwater inflow. Therefore, while some lagoons may be similar to estuaries, it is not universally true for all lagoons.
Based on the analysis above, we can conclude that the correct answer is option 'B' - 2 and 3 only. Statement 1 is incorrect as lagoons can be either fresh or saltwater. Statement 2 is true as lagoons are separated from the sea by sandbars and spits. Statement 3 is also true to some extent, as lagoons can share similarities with estuaries, but it is not universally applicable to all lagoons.
In this question, we are given three statements about lagoons and we need to choose the correct answer using the given options.
Statement 1: Lagoon is a fresh-water lake.
Statement 2: Lagoon is separated from the sea by sandbars and spits.
Statement 3: Lagoon is considered similar to some of the estuaries.
To determine the correct answer, let's analyze each statement.
Statement 1: Lagoon is a fresh-water lake.
A lagoon is not necessarily a fresh-water lake. It can be either fresh or saltwater, depending on its location and connection to the sea. Therefore, this statement is incorrect.
Statement 2: Lagoon is separated from the sea by sandbars and spits.
This statement is true. A lagoon is a shallow body of water separated from the sea by sandbars, spits, or barrier islands. These natural formations act as a barrier, creating a calm and sheltered environment within the lagoon.
Statement 3: Lagoon is considered similar to some of the estuaries.
This statement is also true. Lagoons and estuaries share some similarities. Both are partially enclosed bodies of water connected to the sea. However, there are some differences as well. Lagoons are typically separated from the sea by sandbars or spits, while estuaries are formed at the mouths of rivers and are influenced by freshwater inflow. Therefore, while some lagoons may be similar to estuaries, it is not universally true for all lagoons.
Based on the analysis above, we can conclude that the correct answer is option 'B' - 2 and 3 only. Statement 1 is incorrect as lagoons can be either fresh or saltwater. Statement 2 is true as lagoons are separated from the sea by sandbars and spits. Statement 3 is also true to some extent, as lagoons can share similarities with estuaries, but it is not universally applicable to all lagoons.
A long, narrow sand dune or chain of dunes, generally oriented in a direction parallel to the prevailing wind or a direction resulting from two or more winds blowing at acute angles to each other. This description refers to which type of dune?- a) Barchan
- b) Seif
- c) Loess
- d) Erg
Correct answer is option 'B'. Can you explain this answer?
A long, narrow sand dune or chain of dunes, generally oriented in a direction parallel to the prevailing wind or a direction resulting from two or more winds blowing at acute angles to each other. This description refers to which type of dune?
a)
Barchan
b)
Seif
c)
Loess
d)
Erg
|
|
Anshul Saini answered |
Type of dune: Seif
A seif dune is a long, narrow sand dune or chain of dunes that is generally oriented in a direction parallel to the prevailing wind or a direction resulting from two or more winds blowing at acute angles to each other.
Characteristics of a Seif dune:
- Orientation: Parallel to the prevailing wind direction or a direction resulting from two or more winds blowing at acute angles to each other.
- Shape: Long and narrow with a gentle slope on the windward side and a steep slope on the leeward side.
- Size: Can be several meters to several kilometers long and up to 150 meters high.
- Formation: Results from the movement of sand grains by wind.
Other types of dunes:
- Barchan dune: Crescent-shaped and formed by winds blowing predominantly from one direction.
- Loess: A type of sediment formed from wind-blown dust and silt.
- Erg: Large area covered with sand dunes.
This question belongs to the UPSC category, which is the Union Public Service Commission in India.
A seif dune is a long, narrow sand dune or chain of dunes that is generally oriented in a direction parallel to the prevailing wind or a direction resulting from two or more winds blowing at acute angles to each other.
Characteristics of a Seif dune:
- Orientation: Parallel to the prevailing wind direction or a direction resulting from two or more winds blowing at acute angles to each other.
- Shape: Long and narrow with a gentle slope on the windward side and a steep slope on the leeward side.
- Size: Can be several meters to several kilometers long and up to 150 meters high.
- Formation: Results from the movement of sand grains by wind.
Other types of dunes:
- Barchan dune: Crescent-shaped and formed by winds blowing predominantly from one direction.
- Loess: A type of sediment formed from wind-blown dust and silt.
- Erg: Large area covered with sand dunes.
This question belongs to the UPSC category, which is the Union Public Service Commission in India.
Which of the following about the tectonic ‘Indian Plate’ is not correct? - a) It is a major tectonic plate.
- b) It forms a convergent late boundary with the Himalayas.
- c) The Indian plate is tectonically separated from the Peninsular India plate.
- d) The plate extends to Pakistan and Myanmar as well.
Correct answer is option 'C'. Can you explain this answer?
Which of the following about the tectonic ‘Indian Plate’ is not correct?
a)
It is a major tectonic plate.
b)
It forms a convergent late boundary with the Himalayas.
c)
The Indian plate is tectonically separated from the Peninsular India plate.
d)
The plate extends to Pakistan and Myanmar as well.
|
|
Pooja Shah answered |
- The peninsular plate is an integral part of the Indian plate.
- Plates are divided between major and minor plates based on their geographical coverage. The Indian plate is thus a major plate.
- The subduction zone along the Himalayas forms the northern plate boundary in the form of continent convergence.
- In the east, it extends through Rakim Yoma Mountains of Myanmar towards the island along the Java Trench. The Western margin follows Kirthar Mountain of Pakistan.
What is/are the difference(s) between extrusive and intrusive rocks? 1. Extrusive rocks are formed from magma, whereas intrusive rocks are formed from lava.2. Extrusive rocks arc fine-grained, whereas intrusive rocks arc coarse-grained.3. Extrusive rocks form over a much longer duration of time compared to intrusive rocks.Select the correct answer using the codes below: - a) 2 only
- b) 1 and 3 only
- c) 3 only
- d) 1 only
Correct answer is option 'A'. Can you explain this answer?
What is/are the difference(s) between extrusive and intrusive rocks?
1. Extrusive rocks are formed from magma, whereas intrusive rocks are formed from lava.
2. Extrusive rocks arc fine-grained, whereas intrusive rocks arc coarse-grained.
3. Extrusive rocks form over a much longer duration of time compared to intrusive rocks.
Select the correct answer using the codes below:
a)
2 only
b)
1 and 3 only
c)
3 only
d)
1 only
|
|
Anjana Sharma answered |
Difference between Extrusive and Intrusive Rocks
Introduction
Extrusive and intrusive rocks are two types of igneous rocks that differ in their formation, texture, and the duration of their formation. Understanding these differences is important in the study of geology and helps in identifying and classifying various rock formations.
Formation
1. Extrusive Rocks: Extrusive rocks are formed from magma, which is molten rock that reaches the Earth's surface through volcanic activity. When magma erupts from a volcano, it cools rapidly and solidifies to form extrusive rocks. Examples of extrusive rocks include basalt, obsidian, and pumice.
2. Intrusive Rocks: Intrusive rocks, on the other hand, are formed from lava, which is magma that has reached the Earth's surface. Instead of erupting, lava flows out of the volcano and cools slowly beneath the surface. This slow cooling allows for the formation of large mineral crystals, resulting in coarse-grained textures. Examples of intrusive rocks include granite, gabbro, and diorite.
Texture
1. Extrusive Rocks: Extrusive rocks have a fine-grained texture due to their rapid cooling. As the magma cools quickly at the surface, there is insufficient time for large mineral crystals to form. Instead, small crystals or even glassy structures are observed in extrusive rocks.
2. Intrusive Rocks: Intrusive rocks have a coarse-grained texture because of their slow cooling process. As the magma cools slowly beneath the surface, there is ample time for large mineral crystals to develop. These crystals are often visible to the naked eye and contribute to the coarse-grained appearance of intrusive rocks.
Duration of Formation
1. Extrusive Rocks: Extrusive rocks are formed relatively quickly, as the magma reaches the surface and cools rapidly. This process typically takes place over a short duration of time, such as days or weeks.
2. Intrusive Rocks: In contrast, the formation of intrusive rocks occurs over a much longer duration of time. The slow cooling of lava beneath the surface can take thousands or even millions of years, allowing for the growth of large mineral crystals.
Conclusion
In summary, extrusive and intrusive rocks differ in their formation, texture, and the duration of their formation. Extrusive rocks are formed from magma, have a fine-grained texture, and are formed relatively quickly. In contrast, intrusive rocks are formed from lava, have a coarse-grained texture, and are formed over a longer duration of time. Understanding these differences is essential in the study of igneous rocks and helps in identifying and classifying various geological formations.
Introduction
Extrusive and intrusive rocks are two types of igneous rocks that differ in their formation, texture, and the duration of their formation. Understanding these differences is important in the study of geology and helps in identifying and classifying various rock formations.
Formation
1. Extrusive Rocks: Extrusive rocks are formed from magma, which is molten rock that reaches the Earth's surface through volcanic activity. When magma erupts from a volcano, it cools rapidly and solidifies to form extrusive rocks. Examples of extrusive rocks include basalt, obsidian, and pumice.
2. Intrusive Rocks: Intrusive rocks, on the other hand, are formed from lava, which is magma that has reached the Earth's surface. Instead of erupting, lava flows out of the volcano and cools slowly beneath the surface. This slow cooling allows for the formation of large mineral crystals, resulting in coarse-grained textures. Examples of intrusive rocks include granite, gabbro, and diorite.
Texture
1. Extrusive Rocks: Extrusive rocks have a fine-grained texture due to their rapid cooling. As the magma cools quickly at the surface, there is insufficient time for large mineral crystals to form. Instead, small crystals or even glassy structures are observed in extrusive rocks.
2. Intrusive Rocks: Intrusive rocks have a coarse-grained texture because of their slow cooling process. As the magma cools slowly beneath the surface, there is ample time for large mineral crystals to develop. These crystals are often visible to the naked eye and contribute to the coarse-grained appearance of intrusive rocks.
Duration of Formation
1. Extrusive Rocks: Extrusive rocks are formed relatively quickly, as the magma reaches the surface and cools rapidly. This process typically takes place over a short duration of time, such as days or weeks.
2. Intrusive Rocks: In contrast, the formation of intrusive rocks occurs over a much longer duration of time. The slow cooling of lava beneath the surface can take thousands or even millions of years, allowing for the growth of large mineral crystals.
Conclusion
In summary, extrusive and intrusive rocks differ in their formation, texture, and the duration of their formation. Extrusive rocks are formed from magma, have a fine-grained texture, and are formed relatively quickly. In contrast, intrusive rocks are formed from lava, have a coarse-grained texture, and are formed over a longer duration of time. Understanding these differences is essential in the study of igneous rocks and helps in identifying and classifying various geological formations.
Geos and gloups are the landforms formed by the action of - a) Glaciers
- b) Winds in deserts
- c) Waves
- d) River water
Correct answer is option 'C'. Can you explain this answer?
Geos and gloups are the landforms formed by the action of
a)
Glaciers
b)
Winds in deserts
c)
Waves
d)
River water
|
Vikram Kapoor answered |
Geos is a narrow inlet in a cliff while gloups are blow holes.
The belt of ancient rocks of 2,000 million years from the Brazil coast matches those from western Africa. Also, the earliest marine deposits along the coastline of South America and Africa are of the Jurassic age. What are we talking about?- a) Seafloor Spreading
- b) Environmental Possibilism
- c) Continental Drift Theory
- d) Convectional Current Theory
Correct answer is option 'C'. Can you explain this answer?
The belt of ancient rocks of 2,000 million years from the Brazil coast matches those from western Africa. Also, the earliest marine deposits along the coastline of South America and Africa are of the Jurassic age. What are we talking about?
a)
Seafloor Spreading
b)
Environmental Possibilism
c)
Continental Drift Theory
d)
Convectional Current Theory
|
Srestha Banerjee answered |
Continental Drift Theory
The correct answer is option C, Continental Drift Theory. This theory, proposed by Alfred Wegener in the early 20th century, suggests that the continents were once joined together in a single supercontinent called Pangaea and have since drifted apart.
Key Points:
1. Belt of Ancient Rocks:
The belt of ancient rocks from the Brazil coast that matches those from western Africa is evidence of the existence of a supercontinent. The similarities in the rock formations indicate that these regions were once connected.
2. Matching Ancient Rocks:
The age and composition of the rocks found along the Brazil coast and western Africa are similar, suggesting a common geological history. This similarity supports the idea that these two continents were once part of the same landmass.
3. Earliest Marine Deposits:
The presence of Jurassic age marine deposits along the coastlines of South America and Africa further supports the Continental Drift Theory. The discovery of similar fossils and sedimentary layers in both regions indicates that they were once adjacent and shared the same marine environment.
4. Pangaea:
According to the Continental Drift Theory, approximately 200 million years ago, all the continents were connected as one supercontinent called Pangaea. Over time, Pangaea began to break apart, and the continents we know today gradually drifted to their current positions.
5. Plate Tectonics:
The movement of the continents is explained by the theory of plate tectonics, which states that the Earth's lithosphere is divided into several large plates that float on the semi-fluid asthenosphere below. These plates move and interact with each other, causing various geological phenomena such as earthquakes, volcanic activity, and the drifting of continents.
Conclusion:
The presence of matching ancient rocks and Jurassic age marine deposits between the Brazil coast and western Africa provides strong evidence for the Continental Drift Theory. This theory explains how the continents have moved over millions of years and helps us understand the geological history and formation of the Earth's landmasses.
The correct answer is option C, Continental Drift Theory. This theory, proposed by Alfred Wegener in the early 20th century, suggests that the continents were once joined together in a single supercontinent called Pangaea and have since drifted apart.
Key Points:
1. Belt of Ancient Rocks:
The belt of ancient rocks from the Brazil coast that matches those from western Africa is evidence of the existence of a supercontinent. The similarities in the rock formations indicate that these regions were once connected.
2. Matching Ancient Rocks:
The age and composition of the rocks found along the Brazil coast and western Africa are similar, suggesting a common geological history. This similarity supports the idea that these two continents were once part of the same landmass.
3. Earliest Marine Deposits:
The presence of Jurassic age marine deposits along the coastlines of South America and Africa further supports the Continental Drift Theory. The discovery of similar fossils and sedimentary layers in both regions indicates that they were once adjacent and shared the same marine environment.
4. Pangaea:
According to the Continental Drift Theory, approximately 200 million years ago, all the continents were connected as one supercontinent called Pangaea. Over time, Pangaea began to break apart, and the continents we know today gradually drifted to their current positions.
5. Plate Tectonics:
The movement of the continents is explained by the theory of plate tectonics, which states that the Earth's lithosphere is divided into several large plates that float on the semi-fluid asthenosphere below. These plates move and interact with each other, causing various geological phenomena such as earthquakes, volcanic activity, and the drifting of continents.
Conclusion:
The presence of matching ancient rocks and Jurassic age marine deposits between the Brazil coast and western Africa provides strong evidence for the Continental Drift Theory. This theory explains how the continents have moved over millions of years and helps us understand the geological history and formation of the Earth's landmasses.
Consider the following statements regarding rivers:1. A river drains the water collected from a specific area, which is called its 'catchment area’.2. An area drained by a river and its tributaries is called a drainage basin.3. The boundary line separating one drainage basin from the other is known as the watershed.4. Watersheds are small in area while the basins cover larger areas.Which of the statement(s) given above is/are incorrect? - a) 1 and 2 only
- b) 1, 2 and 3 only
- c) 1 and 3 only
- d) None of the above
Correct answer is option 'D'. Can you explain this answer?
Consider the following statements regarding rivers:
1. A river drains the water collected from a specific area, which is called its 'catchment area’.
2. An area drained by a river and its tributaries is called a drainage basin.
3. The boundary line separating one drainage basin from the other is known as the watershed.
4. Watersheds are small in area while the basins cover larger areas.
Which of the statement(s) given above is/are incorrect?
a)
1 and 2 only
b)
1, 2 and 3 only
c)
1 and 3 only
d)
None of the above
|
|
Nishtha Choudhury answered |
Explanation:
The correct answer is option 'D' - None of the above.
Let's analyze each statement one by one:
Statement 1:
A river drains the water collected from a specific area, which is called its 'catchment area'.
This statement is correct. A river collects water from a specific area, which is known as its catchment area. The catchment area is the area of land where the rainwater or snowmelt flows into the river and its tributaries.
Statement 2:
An area drained by a river and its tributaries is called a drainage basin.
This statement is correct. A drainage basin refers to the area of land that is drained by a river and its tributaries. It includes all the land where the water flows into the river system.
Statement 3:
The boundary line separating one drainage basin from the other is known as the watershed.
This statement is incorrect. The boundary line separating one drainage basin from the other is known as the watershed, not the catchment area. The watershed is the dividing line between two drainage basins, where the water flows in different directions.
Statement 4:
Watersheds are small in area while the basins cover larger areas.
This statement is incorrect. Watersheds are not necessarily small in area compared to basins. The size of a watershed or a drainage basin can vary greatly depending on various factors such as the size of the river and the topography of the land. Some watersheds can be large, covering a vast area, while others can be relatively small.
In conclusion, statement 3 is incorrect while the other statements are correct. Hence, the correct answer is option 'D' - None of the above.
The correct answer is option 'D' - None of the above.
Let's analyze each statement one by one:
Statement 1:
A river drains the water collected from a specific area, which is called its 'catchment area'.
This statement is correct. A river collects water from a specific area, which is known as its catchment area. The catchment area is the area of land where the rainwater or snowmelt flows into the river and its tributaries.
Statement 2:
An area drained by a river and its tributaries is called a drainage basin.
This statement is correct. A drainage basin refers to the area of land that is drained by a river and its tributaries. It includes all the land where the water flows into the river system.
Statement 3:
The boundary line separating one drainage basin from the other is known as the watershed.
This statement is incorrect. The boundary line separating one drainage basin from the other is known as the watershed, not the catchment area. The watershed is the dividing line between two drainage basins, where the water flows in different directions.
Statement 4:
Watersheds are small in area while the basins cover larger areas.
This statement is incorrect. Watersheds are not necessarily small in area compared to basins. The size of a watershed or a drainage basin can vary greatly depending on various factors such as the size of the river and the topography of the land. Some watersheds can be large, covering a vast area, while others can be relatively small.
In conclusion, statement 3 is incorrect while the other statements are correct. Hence, the correct answer is option 'D' - None of the above.
Consider the following statements about igneous rocks: 1. They are generally crystalline.2. They occur in layers and often contain fossils.3. Igneous rocks are always acidic.Choose the correct answer using the codes below: - a) 1 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'A'. Can you explain this answer?
Consider the following statements about igneous rocks:
1. They are generally crystalline.
2. They occur in layers and often contain fossils.
3. Igneous rocks are always acidic.
Choose the correct answer using the codes below:
a)
1 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
|
Anita Desai answered |
- Igneous rocks are formed by solidification of magma and crystals arc formed upon cooling.
- Sedimentary rocks contain fossils. Basaltic rocks which are also the type of igneous rocks are basic due to lower silica content. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ages of rocks and the fossils they host.
Which of these rocks make up for large portions of the crust of Earth?1. Granitic rocks2. Basaltic rocks3. Pumice rocks4. Obsidian rocksChoose the correct answer from the following codes:- a) 2 and 3 only
- b) 1 and 2 only
- c) 1, 3 and 4 only
- d) All of the above
Correct answer is option 'B'. Can you explain this answer?
Which of these rocks make up for large portions of the crust of Earth?
1. Granitic rocks
2. Basaltic rocks
3. Pumice rocks
4. Obsidian rocks
Choose the correct answer from the following codes:
a)
2 and 3 only
b)
1 and 2 only
c)
1, 3 and 4 only
d)
All of the above
|
|
Sneha Mishra answered |
Answer:
Rocks That Make Up the Crust of Earth
The crust of the Earth is made up of various types of rocks, but some of them make up for large portions of it. These rocks are:
1. Granitic rocks
2. Basaltic rocks
Explanation:
Granitic rocks are igneous rocks that are light-colored and have a coarse-grained texture. They are formed from the slow cooling of magma beneath the Earth's surface. They are found in the continental crust and make up a large portion of it.
Basaltic rocks, on the other hand, are dark-colored igneous rocks that have a fine-grained texture. They are formed from the rapid cooling of lava on the Earth's surface. They are found in the oceanic crust and make up a significant portion of it.
Pumice rocks and obsidian rocks are also types of igneous rocks, but they do not make up large portions of the Earth's crust. Pumice rocks are formed from the rapid cooling of lava that is rich in gas bubbles, while obsidian rocks are formed from the rapid cooling of lava that is rich in silica.
Conclusion:
Therefore, the correct answer to this question is option 'B' - 1 and 2 only, as granitic rocks and basaltic rocks make up for large portions of the Earth's crust.
Rocks That Make Up the Crust of Earth
The crust of the Earth is made up of various types of rocks, but some of them make up for large portions of it. These rocks are:
1. Granitic rocks
2. Basaltic rocks
Explanation:
Granitic rocks are igneous rocks that are light-colored and have a coarse-grained texture. They are formed from the slow cooling of magma beneath the Earth's surface. They are found in the continental crust and make up a large portion of it.
Basaltic rocks, on the other hand, are dark-colored igneous rocks that have a fine-grained texture. They are formed from the rapid cooling of lava on the Earth's surface. They are found in the oceanic crust and make up a significant portion of it.
Pumice rocks and obsidian rocks are also types of igneous rocks, but they do not make up large portions of the Earth's crust. Pumice rocks are formed from the rapid cooling of lava that is rich in gas bubbles, while obsidian rocks are formed from the rapid cooling of lava that is rich in silica.
Conclusion:
Therefore, the correct answer to this question is option 'B' - 1 and 2 only, as granitic rocks and basaltic rocks make up for large portions of the Earth's crust.
Regarding seismic waves, consider the following statements:(a) P wave or primary wave is the fastest kind of seismic wave and, consequently, the first to ‘arrive’ at a seismic station.(b) S wave or secondary wave can only move through solid rock, not through any liquid medium.Which of the above statements is/are correct? - a) 1 only
- b) 2 only
- c) Both 1 and 2
- d) None of the above
Correct answer is option 'C'. Can you explain this answer?
Regarding seismic waves, consider the following statements:
(a) P wave or primary wave is the fastest kind of seismic wave and, consequently, the first to ‘arrive’ at a seismic station.
(b) S wave or secondary wave can only move through solid rock, not through any liquid medium.
Which of the above statements is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of the above
|
|
Aarya Mehta answered |
Overview of Seismic Waves
Seismic waves are generated by geological events such as earthquakes and are classified into different types based on their properties. The two main types discussed here are Primary (P) waves and Secondary (S) waves.
P Waves (Primary Waves)
- P waves are indeed the fastest seismic waves.
- They can travel through solids, liquids, and gases.
- Due to their speed, they are the first to be detected by seismic stations after an earthquake occurs.
S Waves (Secondary Waves)
- S waves are slower than P waves and arrive at seismic stations after them.
- They can only travel through solid materials and do not propagate through liquids or gases.
- This property is crucial in understanding the Earth's interior, as the behavior of S waves indicates the presence of liquid layers, such as the outer core.
Correctness of the Statements
1. Statement (a): P wave or primary wave is the fastest kind of seismic wave and, consequently, the first to ‘arrive’ at a seismic station.
- This statement is correct.
2. Statement (b): S wave or secondary wave can only move through solid rock, not through any liquid medium.
- This statement is also correct.
Conclusion
Both statements about P waves and S waves are accurate, confirming that the correct answer is option 'C', as both statements 1 and 2 are true. Understanding these waves provides insight into the internal structure of the Earth and the mechanisms behind seismic events.
Seismic waves are generated by geological events such as earthquakes and are classified into different types based on their properties. The two main types discussed here are Primary (P) waves and Secondary (S) waves.
P Waves (Primary Waves)
- P waves are indeed the fastest seismic waves.
- They can travel through solids, liquids, and gases.
- Due to their speed, they are the first to be detected by seismic stations after an earthquake occurs.
S Waves (Secondary Waves)
- S waves are slower than P waves and arrive at seismic stations after them.
- They can only travel through solid materials and do not propagate through liquids or gases.
- This property is crucial in understanding the Earth's interior, as the behavior of S waves indicates the presence of liquid layers, such as the outer core.
Correctness of the Statements
1. Statement (a): P wave or primary wave is the fastest kind of seismic wave and, consequently, the first to ‘arrive’ at a seismic station.
- This statement is correct.
2. Statement (b): S wave or secondary wave can only move through solid rock, not through any liquid medium.
- This statement is also correct.
Conclusion
Both statements about P waves and S waves are accurate, confirming that the correct answer is option 'C', as both statements 1 and 2 are true. Understanding these waves provides insight into the internal structure of the Earth and the mechanisms behind seismic events.
Which of the following is responsible for bringing changes on the surface of the Earth? 1. Gravitational force2. Tectonic forces3. Electromagnetic radiationWhich of the following statement(s) is/are correct?- a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Which of the following is responsible for bringing changes on the surface of the Earth?
1. Gravitational force
2. Tectonic forces
3. Electromagnetic radiation
Which of the following statement(s) is/are correct?
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
Lekshmi Basak answered |
Answer:
Factors responsible for changes on Earth's surface:
There are several factors responsible for bringing changes on the surface of the Earth. Some of the major factors are discussed below:
1. Tectonic forces:
Tectonic forces include processes like plate tectonics, earthquakes, volcanic eruptions, and mountain building. These forces are responsible for the creation of new landforms and the destruction of existing ones. Plate tectonics is the key process that drives the movement of the Earth's crust.
2. Gravitational force:
The gravitational force of the Earth is responsible for many changes on its surface. It causes erosion, weathering, and mass wasting. Erosion is the process by which the surface of the Earth is worn away by the action of water, wind, or ice. Weathering is the breakdown of rocks into smaller pieces due to the action of weather. Mass wasting is the downhill movement of soil and rock under the influence of gravity.
3. Electromagnetic radiation:
Electromagnetic radiation from the sun is responsible for many changes on the Earth's surface. It causes weather patterns, ocean currents, and the growth of plants. The sun's energy is also responsible for the water cycle, which is the process by which water evaporates from the surface of the Earth and is later returned as precipitation.
Correct answer:
All of the above (1, 2, and 3) are responsible for bringing changes on the surface of the Earth.
Factors responsible for changes on Earth's surface:
There are several factors responsible for bringing changes on the surface of the Earth. Some of the major factors are discussed below:
1. Tectonic forces:
Tectonic forces include processes like plate tectonics, earthquakes, volcanic eruptions, and mountain building. These forces are responsible for the creation of new landforms and the destruction of existing ones. Plate tectonics is the key process that drives the movement of the Earth's crust.
2. Gravitational force:
The gravitational force of the Earth is responsible for many changes on its surface. It causes erosion, weathering, and mass wasting. Erosion is the process by which the surface of the Earth is worn away by the action of water, wind, or ice. Weathering is the breakdown of rocks into smaller pieces due to the action of weather. Mass wasting is the downhill movement of soil and rock under the influence of gravity.
3. Electromagnetic radiation:
Electromagnetic radiation from the sun is responsible for many changes on the Earth's surface. It causes weather patterns, ocean currents, and the growth of plants. The sun's energy is also responsible for the water cycle, which is the process by which water evaporates from the surface of the Earth and is later returned as precipitation.
Correct answer:
All of the above (1, 2, and 3) are responsible for bringing changes on the surface of the Earth.
Which of the following oceanic regions is the primary site of generation of new crust, hosting mineral resources and supporting unique ecosystems?- a) Littoral region
- b) Continental Shelf
- c) Mid-oceanic ridges
- d) Continental rise
Correct answer is option 'C'. Can you explain this answer?
Which of the following oceanic regions is the primary site of generation of new crust, hosting mineral resources and supporting unique ecosystems?
a)
Littoral region
b)
Continental Shelf
c)
Mid-oceanic ridges
d)
Continental rise
|
|
Amit Kumar answered |
The Mid-Ocean Ridge system forms the most extensive chain of mountains on Earth, with more than 90% of the mountain range lying in the deep ocean - with a total length of about 60,000 km. Mid-ocean ridges are geologically important because they occur along divergent plate boundaries, where the new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, some molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt, and building the longest chain of volcanoes in the world. Because most of these eruptions occur deep under the water, they often go unnoticed.
The action of the endogenic forces is not uniform and thus the tectonically controlled original crustal surface is uneven. This can be attributed to factors like 1. Variation in crustal thickness2. Variation in geothermal gradients3. Volcanism in the lithosphereWhich of the following statement(s) is/are correct?- a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
The action of the endogenic forces is not uniform and thus the tectonically controlled original crustal surface is uneven. This can be attributed to factors like
1. Variation in crustal thickness
2. Variation in geothermal gradients
3. Volcanism in the lithosphere
Which of the following statement(s) is/are correct?
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
|
Anjali Rao answered |
- The energy emanating from within the Earth is the main force behind endogenic geomorphic processes.
- This energy mostly generated by radioactivity, rotational and tidal friction and primordial heat from the origin of the Earth.
- This energy due to geothermal gradients and heat flow from within induces diastrophism and volcanism in the lithosphere.
- Due to variations ii geothermal gradients and heat flow from within, crustal thickness and strength, the action of endogenic forces are not uniform and hence the tectonically controlled original crustal surface is uneven.
Which of the following cannot be the use of Lagoons and backwaters?1. Fishing2. Irrigation of paddy crops3. NavigationChoose the correct answer using the codes below: - a) 1 and 3 only
- b) 1 only
- c) 2 only
- d) All of the above
Correct answer is option 'C'. Can you explain this answer?
Which of the following cannot be the use of Lagoons and backwaters?
1. Fishing
2. Irrigation of paddy crops
3. Navigation
Choose the correct answer using the codes below:
a)
1 and 3 only
b)
1 only
c)
2 only
d)
All of the above
|
|
Gopal Datta answered |
Lagoons and backwaters are important natural features that can serve various purposes. However, there are certain limitations to their use. Among the given options, irrigation of paddy crops is the only use that cannot be fulfilled by lagoons and backwaters. Let's discuss each option in detail to understand why.
1. Fishing:
Lagoons and backwaters are often abundant in aquatic life, making them ideal locations for fishing activities. These water bodies provide a suitable habitat for various fish species, making them attractive to fishermen. The calm and shallow waters of lagoons and backwaters support the growth and reproduction of fish, making it a popular fishing ground. Therefore, fishing is a common and feasible use of lagoons and backwaters.
2. Irrigation of paddy crops:
Paddy crops require a constant supply of water for their growth and development. While lagoons and backwaters can store water, they may not be suitable for irrigation purposes. Unlike rivers or canals, lagoons and backwaters may not have a consistent flow of water. The water levels in these water bodies can fluctuate significantly depending on rainfall and tidal movements. Therefore, it may not be reliable or efficient to rely on lagoons and backwaters for irrigation of paddy crops.
3. Navigation:
Lagoons and backwaters can serve as important waterways for navigation. These water bodies often provide a safe and navigable route for boats and ships, especially in coastal areas. They can act as natural harbors or channels, facilitating transportation and trade. Navigating through lagoons and backwaters can offer several advantages, such as avoiding rough seas or congestion in ports. Therefore, navigation is a feasible use of lagoons and backwaters.
In conclusion, fishing and navigation are viable uses of lagoons and backwaters, while irrigation of paddy crops is not. The fluctuating water levels and inconsistency of flow in lagoons and backwaters make them unsuitable for reliable irrigation purposes.
1. Fishing:
Lagoons and backwaters are often abundant in aquatic life, making them ideal locations for fishing activities. These water bodies provide a suitable habitat for various fish species, making them attractive to fishermen. The calm and shallow waters of lagoons and backwaters support the growth and reproduction of fish, making it a popular fishing ground. Therefore, fishing is a common and feasible use of lagoons and backwaters.
2. Irrigation of paddy crops:
Paddy crops require a constant supply of water for their growth and development. While lagoons and backwaters can store water, they may not be suitable for irrigation purposes. Unlike rivers or canals, lagoons and backwaters may not have a consistent flow of water. The water levels in these water bodies can fluctuate significantly depending on rainfall and tidal movements. Therefore, it may not be reliable or efficient to rely on lagoons and backwaters for irrigation of paddy crops.
3. Navigation:
Lagoons and backwaters can serve as important waterways for navigation. These water bodies often provide a safe and navigable route for boats and ships, especially in coastal areas. They can act as natural harbors or channels, facilitating transportation and trade. Navigating through lagoons and backwaters can offer several advantages, such as avoiding rough seas or congestion in ports. Therefore, navigation is a feasible use of lagoons and backwaters.
In conclusion, fishing and navigation are viable uses of lagoons and backwaters, while irrigation of paddy crops is not. The fluctuating water levels and inconsistency of flow in lagoons and backwaters make them unsuitable for reliable irrigation purposes.
Earthquakes occur at 1. Divergent plate boundaries.2. Ocean-ocean convergent plate boundaries.3. Ocean-continent plate boundaries.4. Transform boundaries.Which of the above statements is/are correct? - a) 1, 3 and 4 only
- b) 1, 2 and 4 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Earthquakes occur at
1. Divergent plate boundaries.
2. Ocean-ocean convergent plate boundaries.
3. Ocean-continent plate boundaries.
4. Transform boundaries.
Which of the above statements is/are correct?
a)
1, 3 and 4 only
b)
1, 2 and 4 only
c)
1 and 3 only
d)
All of the above
|
Deepak Kapoor answered |
- The boundaries where the plates meet experience most earthquakes. Locations of earthquakes and the kinds of ruptures they produce serve as a great source of information to scientists to define the plate boundaries. The three types of plate boundaries are spreading zones, transform faults and subduction zones. At spreading zones, molten rock rises, which pushes two plates apart and adds new material at their corners.
- Divergent boundaries are those at which crustal plates move away from each other, such as at mid-oceanic ridges.
- The formation of a new ocean crust that is pushed away from both sides of the ridge fault creates a tension setting that results in the formation of the graben. Earthquakes arc located along the normal faults that form the sides of the rift or beneath the floor of the rift.
- Transform faults are found where plates slide past one another. Shallow-focus earthquakes occur along transform boundaries where two plates move past each other.
Conditions that favour the formation of deltas include 1. Coasts without shelters with a large tidal variation.2. Frequent water diversions from the main river that forms the delta.3. Presence of Continental shelf.Select the correct answer using the codes below: - a) 1 and 2 only
- b) 3 only
- c) 2 and 3 only
- d) 1 and 3 only
Correct answer is option 'B'. Can you explain this answer?
Conditions that favour the formation of deltas include
1. Coasts without shelters with a large tidal variation.
2. Frequent water diversions from the main river that forms the delta.
3. Presence of Continental shelf.
Select the correct answer using the codes below:
a)
1 and 2 only
b)
3 only
c)
2 and 3 only
d)
1 and 3 only
|
|
Suresh Reddy answered |
Conditions favourable for Delta Formation
- Active erosion of the river in its upper course to provide extensive gravel, sand and silt to be eventually deposited as deltas.
- The coast should be sheltered preferably tideless, else delta will be washed away.
- There should be no strong current running at right angles to the river mouth, as it can wash away the sediments. Any large lake in the way of the river course can filter off the sediments, thus unfavourable for delta formation. The sea should be shallow adjoining the delta as the sediments will disappear in the deep waters of the sea. This is why a continental shelf is preferred.
Regarding Sea weeds, consider the following statements1.Seaweeds, are plant-like organisms that generally live attached to rock or other hard substrata in coastal areas.2. All seaweeds are edible, though some are more nutritional and palatable than others, and some can cause stomach upset.Which of the statements given above is/are correct? - a)Both 1 and 2
- b)2 only
- c)1 only
- d)Neither 1 nor 2
Correct answer is option 'C'. Can you explain this answer?
Regarding Sea weeds, consider the following statements
1.Seaweeds, are plant-like organisms that generally live attached to rock or other hard substrata in coastal areas.
2. All seaweeds are edible, though some are more nutritional and palatable than others, and some can cause stomach upset.
Which of the statements given above is/are correct?
a)
Both 1 and 2
b)
2 only
c)
1 only
d)
Neither 1 nor 2
|
|
Prateek Chauhan answered |
Understanding Seaweeds
Seaweeds are fascinating organisms that play a crucial role in marine ecosystems. Let's analyze the given statements to determine their accuracy.
Statement 1: Seaweeds are plant-like organisms that generally live attached to rock or other hard substrata in coastal areas.
- This statement is correct.
- Seaweeds, also known as macroalgae, are indeed plant-like organisms.
- They primarily inhabit coastal areas, where they attach themselves to rocks or hard substrates.
- Their growth forms contribute significantly to marine biodiversity, providing habitats and food for various marine organisms.
Statement 2: All seaweeds are edible, though some are more nutritional and palatable than others, and some can cause stomach upset.
- This statement is incorrect.
- While many seaweeds are edible and consumed in various cuisines around the world, not all species are safe for human consumption.
- Some seaweeds can be toxic or indigestible, leading to stomach upset or other health issues.
- Therefore, it is essential to identify seaweed species properly before consumption.
Conclusion
Given the analysis above, the correct answer is option C: "1 only."
- Statement 1 is true, while Statement 2 is false due to the presence of non-edible and potentially harmful seaweed species.
- This distinction highlights the importance of understanding marine flora for both ecological and culinary purposes.
Seaweeds are fascinating organisms that play a crucial role in marine ecosystems. Let's analyze the given statements to determine their accuracy.
Statement 1: Seaweeds are plant-like organisms that generally live attached to rock or other hard substrata in coastal areas.
- This statement is correct.
- Seaweeds, also known as macroalgae, are indeed plant-like organisms.
- They primarily inhabit coastal areas, where they attach themselves to rocks or hard substrates.
- Their growth forms contribute significantly to marine biodiversity, providing habitats and food for various marine organisms.
Statement 2: All seaweeds are edible, though some are more nutritional and palatable than others, and some can cause stomach upset.
- This statement is incorrect.
- While many seaweeds are edible and consumed in various cuisines around the world, not all species are safe for human consumption.
- Some seaweeds can be toxic or indigestible, leading to stomach upset or other health issues.
- Therefore, it is essential to identify seaweed species properly before consumption.
Conclusion
Given the analysis above, the correct answer is option C: "1 only."
- Statement 1 is true, while Statement 2 is false due to the presence of non-edible and potentially harmful seaweed species.
- This distinction highlights the importance of understanding marine flora for both ecological and culinary purposes.
Consider the following statements: 1. Estuaries are more favorable than deltas for the siting of large ports.2. In the outwash plains, eskers and kames have been excavated to provide sands and gravels for highway and building construction.3. Limestone vegetation in tropical regions is luxuriant because of the heavy rainfall all the year round.Which of the statements given above is/are correct? - a) 1 and 3 only
- b) 1, 2 and 3 only
- c) 3 only
- d) 1 only
Correct answer is option 'B'. Can you explain this answer?
Consider the following statements:
1. Estuaries are more favorable than deltas for the siting of large ports.
2. In the outwash plains, eskers and kames have been excavated to provide sands and gravels for highway and building construction.
3. Limestone vegetation in tropical regions is luxuriant because of the heavy rainfall all the year round.
Which of the statements given above is/are correct?
a)
1 and 3 only
b)
1, 2 and 3 only
c)
3 only
d)
1 only
|
|
Saptarshi Patel answered |
Explanation:
Statement 1: Estuaries are more favorable than deltas for the siting of large ports.
- Estuaries are coastal areas where rivers meet the sea and freshwater mixes with saltwater. They typically have deep channels and provide natural shelter from storms and high waves.
- Deltas, on the other hand, are formed at the mouths of rivers where sediment is deposited and can create shallow and shifting channels.
- Estuaries are more favorable for the siting of large ports because their deeper channels allow for larger ships to navigate and dock. They also provide natural protection from strong waves and storms, making it easier for ships to enter and exit the port.
Statement 2: In the outwash plains, eskers and kames have been excavated to provide sands and gravels for highway and building construction.
- Outwash plains are formed by the deposition of sediment carried by meltwater streams from glaciers. They typically consist of sand and gravel deposits.
- Eskers are long, winding ridges of sediment deposited by meltwater streams within or underneath glaciers.
- Kames are small mounds of sediment deposited by meltwater streams on the surface of glaciers.
- In some cases, eskers and kames found in outwash plains are excavated to provide sands and gravels for highway and building construction. These sediments can be used as construction materials due to their composition and availability in outwash plains.
Statement 3: Limestone vegetation in tropical regions is luxuriant because of the heavy rainfall all the year round.
- Limestone vegetation refers to plant life that grows on limestone rock formations. Limestone is a sedimentary rock formed from the accumulation of marine organisms over time.
- In tropical regions, where there is heavy rainfall throughout the year, limestone vegetation tends to be luxuriant.
- The heavy rainfall provides ample moisture for plant growth, and the limestone rock formations often have crevices and fissures that can retain water, creating favorable conditions for plant growth.
- Additionally, limestone is a rich source of essential minerals and nutrients for plants, which further contributes to the luxuriant growth of vegetation in tropical regions.
Conclusion:
- Based on the explanations above, it can be concluded that all three statements are correct.
- Estuaries are indeed more favorable than deltas for the siting of large ports, eskers and kames in outwash plains are excavated for construction materials, and limestone vegetation in tropical regions is luxuriant due to heavy rainfall.
Statement 1: Estuaries are more favorable than deltas for the siting of large ports.
- Estuaries are coastal areas where rivers meet the sea and freshwater mixes with saltwater. They typically have deep channels and provide natural shelter from storms and high waves.
- Deltas, on the other hand, are formed at the mouths of rivers where sediment is deposited and can create shallow and shifting channels.
- Estuaries are more favorable for the siting of large ports because their deeper channels allow for larger ships to navigate and dock. They also provide natural protection from strong waves and storms, making it easier for ships to enter and exit the port.
Statement 2: In the outwash plains, eskers and kames have been excavated to provide sands and gravels for highway and building construction.
- Outwash plains are formed by the deposition of sediment carried by meltwater streams from glaciers. They typically consist of sand and gravel deposits.
- Eskers are long, winding ridges of sediment deposited by meltwater streams within or underneath glaciers.
- Kames are small mounds of sediment deposited by meltwater streams on the surface of glaciers.
- In some cases, eskers and kames found in outwash plains are excavated to provide sands and gravels for highway and building construction. These sediments can be used as construction materials due to their composition and availability in outwash plains.
Statement 3: Limestone vegetation in tropical regions is luxuriant because of the heavy rainfall all the year round.
- Limestone vegetation refers to plant life that grows on limestone rock formations. Limestone is a sedimentary rock formed from the accumulation of marine organisms over time.
- In tropical regions, where there is heavy rainfall throughout the year, limestone vegetation tends to be luxuriant.
- The heavy rainfall provides ample moisture for plant growth, and the limestone rock formations often have crevices and fissures that can retain water, creating favorable conditions for plant growth.
- Additionally, limestone is a rich source of essential minerals and nutrients for plants, which further contributes to the luxuriant growth of vegetation in tropical regions.
Conclusion:
- Based on the explanations above, it can be concluded that all three statements are correct.
- Estuaries are indeed more favorable than deltas for the siting of large ports, eskers and kames in outwash plains are excavated for construction materials, and limestone vegetation in tropical regions is luxuriant due to heavy rainfall.
Sedimentary rocks can be directly formed from which of the following?1. Magma2. Igneous rocks3. Mclamomhic rocksChoose the correct answer using the codes below:- a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) 2 only
Correct answer is option 'B'. Can you explain this answer?
Sedimentary rocks can be directly formed from which of the following?
1. Magma
2. Igneous rocks
3. Mclamomhic rocks
Choose the correct answer using the codes below:
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
2 only
|
|
Akshita Menon answered |
Sedimentary rocks can be directly formed from which of the following:
1. Magma
2. Igneous rocks
3. Metamorphic rocks
The correct answer is option 'B' which is 2 and 3 only.
Explanation:
Sedimentary rocks are formed from the accumulation of sediments or organic matter that have been deposited in layers over time. These sediments can come from a variety of sources such as weathering and erosion of other rocks, as well as the remains of plants and animals.
Sedimentary rocks can be directly formed from two types of rocks:
1. Igneous rocks: These rocks are formed from the cooling and solidification of magma or lava. When these rocks are weathered and eroded, they can break down into sediments which can then be deposited and compacted to form sedimentary rocks.
2. Metamorphic rocks: These rocks are formed from the alteration of pre-existing rocks due to heat and pressure. When these rocks are weathered and eroded, they can break down into sediments which can then be deposited and compacted to form sedimentary rocks.
However, sedimentary rocks cannot be directly formed from magma as it cools and solidifies to form igneous rocks, nor from metamorphic rocks as they are already altered from pre-existing rocks.
Therefore, the correct answer is option 'B' which is 2 and 3 only.
1. Magma
2. Igneous rocks
3. Metamorphic rocks
The correct answer is option 'B' which is 2 and 3 only.
Explanation:
Sedimentary rocks are formed from the accumulation of sediments or organic matter that have been deposited in layers over time. These sediments can come from a variety of sources such as weathering and erosion of other rocks, as well as the remains of plants and animals.
Sedimentary rocks can be directly formed from two types of rocks:
1. Igneous rocks: These rocks are formed from the cooling and solidification of magma or lava. When these rocks are weathered and eroded, they can break down into sediments which can then be deposited and compacted to form sedimentary rocks.
2. Metamorphic rocks: These rocks are formed from the alteration of pre-existing rocks due to heat and pressure. When these rocks are weathered and eroded, they can break down into sediments which can then be deposited and compacted to form sedimentary rocks.
However, sedimentary rocks cannot be directly formed from magma as it cools and solidifies to form igneous rocks, nor from metamorphic rocks as they are already altered from pre-existing rocks.
Therefore, the correct answer is option 'B' which is 2 and 3 only.
Regarding properties of lava, consider the following statements:
1. Basic lavas are the hottest lavas and are highly fluid.
2. When Basic lava flows from a volcano, it is very explosive.
3. Acid lavas arc highly viscous and cause less explosive volcanoes.
4. Acid lava is also called as felsic lava.
Which of the above is/are correct?
- a)3 and 4 only
- b)2 and 3 only
- c)1, 2 and 4 only
- d)1 and 4 only
Correct answer is option 'A'. Can you explain this answer?
Regarding properties of lava, consider the following statements:
1. Basic lavas are the hottest lavas and are highly fluid.
2. When Basic lava flows from a volcano, it is very explosive.
3. Acid lavas arc highly viscous and cause less explosive volcanoes.
4. Acid lava is also called as felsic lava.
Which of the above is/are correct?
a)
3 and 4 only
b)
2 and 3 only
c)
1, 2 and 4 only
d)
1 and 4 only
|
|
Ankita Sarkar answered |
Properties of Lava:
Basic Lava:
- Basic lavas are the hottest lavas and are highly fluid.
- These lavas have low viscosity and can flow easily.
- They have a low gas content and therefore, do not cause explosive volcanoes.
- Basic lava is also called as mafic lava.
Acid Lava:
- Acid lavas are highly viscous and cause less explosive volcanoes.
- These lavas have a high gas content and therefore, tend to be explosive.
- Acid lava is also called as felsic lava.
Correct Answer:
- Statement 1 is correct as basic lavas are hot and highly fluid.
- Statement 4 is correct as acid lava is also called felsic lava.
- Therefore, option 'A' is the correct answer.
Incorrect statements:
- Statement 2 is incorrect as basic lava does not cause explosive volcanoes.
- Statement 3 is incorrect as acid lavas are highly viscous and tend to be explosive.
Basic Lava:
- Basic lavas are the hottest lavas and are highly fluid.
- These lavas have low viscosity and can flow easily.
- They have a low gas content and therefore, do not cause explosive volcanoes.
- Basic lava is also called as mafic lava.
Acid Lava:
- Acid lavas are highly viscous and cause less explosive volcanoes.
- These lavas have a high gas content and therefore, tend to be explosive.
- Acid lava is also called as felsic lava.
Correct Answer:
- Statement 1 is correct as basic lavas are hot and highly fluid.
- Statement 4 is correct as acid lava is also called felsic lava.
- Therefore, option 'A' is the correct answer.
Incorrect statements:
- Statement 2 is incorrect as basic lava does not cause explosive volcanoes.
- Statement 3 is incorrect as acid lavas are highly viscous and tend to be explosive.
In India, rocks of which of the following regions was formed the earliest?- a) Khasi hilts
- b) Lower Siwaliks
- c) Indo-Gangetic plain
- d) Deccan Traps
Correct answer is option 'D'. Can you explain this answer?
In India, rocks of which of the following regions was formed the earliest?
a)
Khasi hilts
b)
Lower Siwaliks
c)
Indo-Gangetic plain
d)
Deccan Traps
|
|
Gauri Bajaj answered |
The correct answer is option 'D' - Deccan Traps.
Explanation:
The Deccan Traps is a large volcanic province located in west-central India. It is composed of multiple layers of solidified basalt lava flows. The rocks of the Deccan Traps were formed during the Late Cretaceous period, approximately 66 million years ago.
Formation of the Deccan Traps:
1. Geological Activity: The formation of the Deccan Traps can be attributed to intense volcanic activity that occurred during the breakup of the supercontinent Gondwana.
2. Massive Eruptions: The volcanic activity resulted in massive eruptions that released vast amounts of basaltic lava onto the surface.
3. Lava Flows: The lava flows spread over an area of approximately 500,000 square kilometers, covering the present-day states of Maharashtra, Madhya Pradesh, Gujarat, and Karnataka.
4. Layered Structure: Over time, the successive eruptions led to the formation of multiple layers of solidified lava flows, creating a distinctive layered structure.
5. Thickness and Extent: The Deccan Traps cover an immense thickness of up to 2,000 meters and are considered one of the largest volcanic provinces in the world.
Importance of the Deccan Traps:
1. Geological Significance: The Deccan Traps hold immense geological significance as they provide valuable insights into the Earth's history, climate changes, and mass extinctions.
2. Mass Extinction Event: The timing of the Deccan Traps' formation coincides with the mass extinction event that resulted in the extinction of the dinosaurs. It is believed that the volcanic activity and the release of gases and aerosols had a significant impact on the global climate, contributing to the extinction event.
3. Mineral Resources: The Deccan Traps also contain various mineral resources, including basalt, granite, and limestone, which are important for construction and industrial purposes.
In conclusion, the rocks of the Deccan Traps in India were formed the earliest among the given options. The intense volcanic activity during the Late Cretaceous period led to the deposition of multiple layers of solidified basalt lava flows, creating the distinctive geological formation known as the Deccan Traps.
Explanation:
The Deccan Traps is a large volcanic province located in west-central India. It is composed of multiple layers of solidified basalt lava flows. The rocks of the Deccan Traps were formed during the Late Cretaceous period, approximately 66 million years ago.
Formation of the Deccan Traps:
1. Geological Activity: The formation of the Deccan Traps can be attributed to intense volcanic activity that occurred during the breakup of the supercontinent Gondwana.
2. Massive Eruptions: The volcanic activity resulted in massive eruptions that released vast amounts of basaltic lava onto the surface.
3. Lava Flows: The lava flows spread over an area of approximately 500,000 square kilometers, covering the present-day states of Maharashtra, Madhya Pradesh, Gujarat, and Karnataka.
4. Layered Structure: Over time, the successive eruptions led to the formation of multiple layers of solidified lava flows, creating a distinctive layered structure.
5. Thickness and Extent: The Deccan Traps cover an immense thickness of up to 2,000 meters and are considered one of the largest volcanic provinces in the world.
Importance of the Deccan Traps:
1. Geological Significance: The Deccan Traps hold immense geological significance as they provide valuable insights into the Earth's history, climate changes, and mass extinctions.
2. Mass Extinction Event: The timing of the Deccan Traps' formation coincides with the mass extinction event that resulted in the extinction of the dinosaurs. It is believed that the volcanic activity and the release of gases and aerosols had a significant impact on the global climate, contributing to the extinction event.
3. Mineral Resources: The Deccan Traps also contain various mineral resources, including basalt, granite, and limestone, which are important for construction and industrial purposes.
In conclusion, the rocks of the Deccan Traps in India were formed the earliest among the given options. The intense volcanic activity during the Late Cretaceous period led to the deposition of multiple layers of solidified basalt lava flows, creating the distinctive geological formation known as the Deccan Traps.
All rocks whether igneous or sedimentary can become metamorphic rocks under great temperature and pressure. In this regard, which of the conversions to metamorphic rocks below is correct?1. Clay to slate2. Coal to graphite3. Sandstone to quartzite4. Shale to schistWhich of the above statements is/are correct? - a) 2 and 3 only
- b) 1 and 2 only
- c) 1,3 and 4 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
All rocks whether igneous or sedimentary can become metamorphic rocks under great temperature and pressure. In this regard, which of the conversions to metamorphic rocks below is correct?
1. Clay to slate
2. Coal to graphite
3. Sandstone to quartzite
4. Shale to schist
Which of the above statements is/are correct?
a)
2 and 3 only
b)
1 and 2 only
c)
1,3 and 4 only
d)
All of the above
|
|
Preethi Kumar answered |
Explanation:
Metamorphic rocks are formed when existing rocks, either igneous or sedimentary, undergo a transformation due to intense heat and pressure. This process causes the minerals in the rocks to recrystallize, resulting in a new rock with different physical and chemical properties.
The correct conversions to metamorphic rocks are:
1. Clay to slate: Clay is a sedimentary rock composed mainly of fine-grained minerals. Under high pressure and temperature, the minerals in the clay recrystallize, forming a dense, fine-grained rock called slate. Slate is characterized by its ability to be easily split into thin, flat sheets.
2. Coal to graphite: Coal is a sedimentary rock formed from the remains of plant material. When subjected to high temperature and pressure, coal undergoes a metamorphic transformation and turns into graphite. Graphite is a crystalline form of carbon with a layered structure and is known for its lubricating properties and use in pencils.
3. Sandstone to quartzite: Sandstone is a sedimentary rock composed of sand-sized grains of mineral, rock, or organic material. Under intense heat and pressure, the sand grains in sandstone recrystallize and fuse together, forming a harder and more compact rock called quartzite. Quartzite is composed mainly of quartz and is known for its durability and resistance to weathering.
4. Shale to schist: Shale is a sedimentary rock composed of fine particles of clay minerals. When subjected to high temperature and pressure, shale undergoes metamorphism and transforms into a metamorphic rock called schist. Schist is characterized by its foliated texture, with minerals aligned in layers or bands.
Therefore, the correct conversions to metamorphic rocks are 1, 2, 3, and 4. Thus, option 'D' - "All of the above" is the correct answer.
Metamorphic rocks are formed when existing rocks, either igneous or sedimentary, undergo a transformation due to intense heat and pressure. This process causes the minerals in the rocks to recrystallize, resulting in a new rock with different physical and chemical properties.
The correct conversions to metamorphic rocks are:
1. Clay to slate: Clay is a sedimentary rock composed mainly of fine-grained minerals. Under high pressure and temperature, the minerals in the clay recrystallize, forming a dense, fine-grained rock called slate. Slate is characterized by its ability to be easily split into thin, flat sheets.
2. Coal to graphite: Coal is a sedimentary rock formed from the remains of plant material. When subjected to high temperature and pressure, coal undergoes a metamorphic transformation and turns into graphite. Graphite is a crystalline form of carbon with a layered structure and is known for its lubricating properties and use in pencils.
3. Sandstone to quartzite: Sandstone is a sedimentary rock composed of sand-sized grains of mineral, rock, or organic material. Under intense heat and pressure, the sand grains in sandstone recrystallize and fuse together, forming a harder and more compact rock called quartzite. Quartzite is composed mainly of quartz and is known for its durability and resistance to weathering.
4. Shale to schist: Shale is a sedimentary rock composed of fine particles of clay minerals. When subjected to high temperature and pressure, shale undergoes metamorphism and transforms into a metamorphic rock called schist. Schist is characterized by its foliated texture, with minerals aligned in layers or bands.
Therefore, the correct conversions to metamorphic rocks are 1, 2, 3, and 4. Thus, option 'D' - "All of the above" is the correct answer.
The major characteristics of the Archaean rock system is that - a) It was formed before the appearance of life in the geologic sequence.
- b) It was the first metamorphic sedimentary rock.
- c) It hosts the major coal deposits of India.
- d) These rocks are largely igneous
Correct answer is option 'A'. Can you explain this answer?
The major characteristics of the Archaean rock system is that
a)
It was formed before the appearance of life in the geologic sequence.
b)
It was the first metamorphic sedimentary rock.
c)
It hosts the major coal deposits of India.
d)
These rocks are largely igneous
|
|
Pooja Choudhury answered |
- The Azoic Age was used to describe the age of rocks formed before the appearance of life in the geologic sequence. Also known as Pre-Cambrian rocks, these are the oldest rocks of the Earth’s crust.
- The Archaean period covers over 85 % of the total geological history time of Earth and therefore is very significant. This period marks the development of the first photosynthesis, the life support atmosphere.
- The Archaean or Purana rock system in India is found in Aravallis mountains, two- thirds of the Deccan peninsula and some parts of the North-east.
Hot Spots within the earth help produce Geothermal Energy. What are these ‘Hot Spots’?
- a)Areas of intense pressure inside the mantle
- b)Region in the crust where hot molten rocks are trapped
- c)Regions of high volcanism on Earth’s surface
- d)Areas of intense magnetic activity within the upper mantle
Correct answer is option 'B'. Can you explain this answer?
Hot Spots within the earth help produce Geothermal Energy. What are these ‘Hot Spots’?
a)
Areas of intense pressure inside the mantle
b)
Region in the crust where hot molten rocks are trapped
c)
Regions of high volcanism on Earth’s surface
d)
Areas of intense magnetic activity within the upper mantle
|
|
Nilesh Patel answered |
Due to geological changes, molten rocks formed in the deeper hot regions of earth’s crust are pushed upward and trapped in certain regions called ‘hot spots’. When underground water comes in contact with the hot spot, steam is generated. Sometimes hot water from that region finds outlets at the surface. Such outlets are known as hot springs.
Tectonic plateaus are formed due to Earth movements that cause uplifts. Consider the following statements:1. Meseta of Central Iberia2. Harz of Germany3. Bolivian plateau found between two ranges of AndesWhich of the following are tectonic plateaus found on Earth? - a) 2 and 3 only
- b) 1 and 2 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Tectonic plateaus are formed due to Earth movements that cause uplifts. Consider the following statements:
1. Meseta of Central Iberia
2. Harz of Germany
3. Bolivian plateau found between two ranges of Andes
Which of the following are tectonic plateaus found on Earth?
a)
2 and 3 only
b)
1 and 2 only
c)
1 and 3 only
d)
All of the above
|
|
Kirti Pillai answered |
Introduction:
Tectonic plateaus are elevated landforms that are formed due to tectonic forces, primarily uplifts caused by the movement of tectonic plates. These plateaus are characterized by extensive flat or gently sloping surfaces and are found all over the world. In this question, we are asked to identify the tectonic plateaus among the given options.
Explanation:
Let's examine each option to identify the tectonic plateaus:
1. Meseta of Central Iberia:
The Meseta of Central Iberia is a large plateau located in Spain. It is formed by the uplift of the Central Iberian Range, which is a result of the collision between the Eurasian and African tectonic plates. The plateau is surrounded by mountain ranges and has an average elevation of around 600-800 meters. Therefore, this is a tectonic plateau.
2. Harz of Germany:
The Harz region in Germany is a mountain range rather than a plateau. It is formed by the uplift of ancient rocks during the Variscan orogeny. The region is characterized by rugged terrain, deep valleys, and steep slopes. Therefore, Harz is not a tectonic plateau.
3. Bolivian plateau found between two ranges of Andes:
The Bolivian plateau, also known as the Altiplano, is a high plateau located in the Andes Mountains of South America. It is situated between two ranges of the Andes, the Cordillera Occidental and the Cordillera Oriental. The plateau is the result of tectonic forces associated with the convergence of the Nazca and South American plates. It has an average elevation of around 3,700 meters and is characterized by vast expanses of flat or gently sloping terrain. Therefore, the Bolivian plateau is a tectonic plateau.
Conclusion:
Based on the above analysis, we can conclude that the tectonic plateaus found on Earth among the given options are:
1. Meseta of Central Iberia
2. Bolivian plateau found between two ranges of Andes.
Therefore, the correct answer is option 'D' - All of the above.
Tectonic plateaus are elevated landforms that are formed due to tectonic forces, primarily uplifts caused by the movement of tectonic plates. These plateaus are characterized by extensive flat or gently sloping surfaces and are found all over the world. In this question, we are asked to identify the tectonic plateaus among the given options.
Explanation:
Let's examine each option to identify the tectonic plateaus:
1. Meseta of Central Iberia:
The Meseta of Central Iberia is a large plateau located in Spain. It is formed by the uplift of the Central Iberian Range, which is a result of the collision between the Eurasian and African tectonic plates. The plateau is surrounded by mountain ranges and has an average elevation of around 600-800 meters. Therefore, this is a tectonic plateau.
2. Harz of Germany:
The Harz region in Germany is a mountain range rather than a plateau. It is formed by the uplift of ancient rocks during the Variscan orogeny. The region is characterized by rugged terrain, deep valleys, and steep slopes. Therefore, Harz is not a tectonic plateau.
3. Bolivian plateau found between two ranges of Andes:
The Bolivian plateau, also known as the Altiplano, is a high plateau located in the Andes Mountains of South America. It is situated between two ranges of the Andes, the Cordillera Occidental and the Cordillera Oriental. The plateau is the result of tectonic forces associated with the convergence of the Nazca and South American plates. It has an average elevation of around 3,700 meters and is characterized by vast expanses of flat or gently sloping terrain. Therefore, the Bolivian plateau is a tectonic plateau.
Conclusion:
Based on the above analysis, we can conclude that the tectonic plateaus found on Earth among the given options are:
1. Meseta of Central Iberia
2. Bolivian plateau found between two ranges of Andes.
Therefore, the correct answer is option 'D' - All of the above.
Fold mountains are formed due to large- scale movements in the Earth’s surface when stresses are set up in the Earth’s crust. What is/are the possible reason(s) for this?1. Increased load of overlying rocks2. Flow movements in the mantle3. Magnetic intrusions in the crustChoose the correct answer using the codes below:- a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Fold mountains are formed due to large- scale movements in the Earth’s surface when stresses are set up in the Earth’s crust. What is/are the possible reason(s) for this?
1. Increased load of overlying rocks
2. Flow movements in the mantle
3. Magnetic intrusions in the crust
Choose the correct answer using the codes below:
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
|
Priya Menon answered |
Fold mountains are formed due to compressive action of forces in the Earth's crust. These are driven by magmatic convection.
Deltas are formed when a river nears the sea and starts depositing its sediment load in the plains. Which of the following can be the consequences of delta formation? 1. Change of river course2. Formation of several distributaries of the original river3. Fertility of the local soil increases.Choose the correct answer using the codes below: - a) 1 and 2 only
- b) 2 and 3 only
- c) 1 and 3 only
- d) All of the above
Correct answer is option 'D'. Can you explain this answer?
Deltas are formed when a river nears the sea and starts depositing its sediment load in the plains. Which of the following can be the consequences of delta formation?
1. Change of river course
2. Formation of several distributaries of the original river
3. Fertility of the local soil increases.
Choose the correct answer using the codes below:
a)
1 and 2 only
b)
2 and 3 only
c)
1 and 3 only
d)
All of the above
|
Arnav Malik answered |
Delta formation can have several consequences that can significantly impact the surrounding environment. These consequences include:
1. Change of river course:
When a river nears the sea and starts depositing its sediment load in the plains, the formation of a delta can cause a change in the course of the river. As the sediment accumulates at the river mouth, it can block the main channel and force the river to take a new path. This change in course can lead to the abandonment of the old channel and the formation of a new one. This process is known as avulsion.
2. Formation of several distributaries of the original river:
As the river deposits sediment at its mouth, it may create multiple channels or distributaries that branch out from the main river. These distributaries carry the sediment and water from the river to different areas, creating a network of channels that spread out across the delta. This branching pattern is often seen in large river deltas, such as the Mississippi Delta or the Ganges-Brahmaputra Delta.
3. Fertility of the local soil increases:
Deltaic soils are generally highly fertile due to the deposition of sediment carried by the river. The sediment deposited by the river contains minerals and nutrients that enrich the soil, making it suitable for agriculture. The constant flooding and deposition of sediment also help to replenish the soil with new nutrients, further enhancing its fertility. As a result, deltaic regions often support extensive agricultural activities and are considered highly productive.
In conclusion, the consequences of delta formation include a change in the river course, the formation of distributaries, and an increase in the fertility of the local soil. These consequences have both natural and human impacts on the environment, influencing river dynamics, landforms, and agricultural practices in deltaic regions.
1. Change of river course:
When a river nears the sea and starts depositing its sediment load in the plains, the formation of a delta can cause a change in the course of the river. As the sediment accumulates at the river mouth, it can block the main channel and force the river to take a new path. This change in course can lead to the abandonment of the old channel and the formation of a new one. This process is known as avulsion.
2. Formation of several distributaries of the original river:
As the river deposits sediment at its mouth, it may create multiple channels or distributaries that branch out from the main river. These distributaries carry the sediment and water from the river to different areas, creating a network of channels that spread out across the delta. This branching pattern is often seen in large river deltas, such as the Mississippi Delta or the Ganges-Brahmaputra Delta.
3. Fertility of the local soil increases:
Deltaic soils are generally highly fertile due to the deposition of sediment carried by the river. The sediment deposited by the river contains minerals and nutrients that enrich the soil, making it suitable for agriculture. The constant flooding and deposition of sediment also help to replenish the soil with new nutrients, further enhancing its fertility. As a result, deltaic regions often support extensive agricultural activities and are considered highly productive.
In conclusion, the consequences of delta formation include a change in the river course, the formation of distributaries, and an increase in the fertility of the local soil. These consequences have both natural and human impacts on the environment, influencing river dynamics, landforms, and agricultural practices in deltaic regions.
Consider the following statements: 1. Wind gaps in the course of a river do not allow the construction of upland roads and railways.2. Deltas are less preferred sites than estuaries for the siting of large ports.Which of the given statements is/are correct? - a) 1 only
- b) 2 only
- c) Both 1 and 2
- d) None of the above
Correct answer is option 'B'. Can you explain this answer?
Consider the following statements:
1. Wind gaps in the course of a river do not allow the construction of upland roads and railways.
2. Deltas are less preferred sites than estuaries for the siting of large ports.
Which of the given statements is/are correct?
a)
1 only
b)
2 only
c)
Both 1 and 2
d)
None of the above
|
|
Atharva Ghosh answered |
Statement 1: Wind gaps in the course of a river do not allow the construction of upland roads and railways.
Explanation:
- Wind gaps are narrow passages or valleys in mountain ranges that are formed due to erosion by wind.
- These gaps are typically located in upland areas where rivers have cut through the mountain ranges.
- Due to their narrow and steep nature, wind gaps pose significant challenges for the construction of roads and railways.
- Constructing roads and railways in wind gaps would require extensive engineering efforts and may not be economically or technically feasible.
- The difficult topography, limited space, and high terrain make it challenging to create a stable and safe infrastructure in wind gaps.
- Therefore, it is correct to say that wind gaps in the course of a river do not allow the construction of upland roads and railways.
Statement 2: Deltas are less preferred sites than estuaries for the siting of large ports.
Explanation:
- Deltas are landforms formed at the mouth of a river where it meets a body of water, typically a sea or an ocean.
- Estuaries, on the other hand, are the areas where a river meets the sea and freshwater mixes with saltwater.
- Both deltas and estuaries are potential sites for the siting of large ports due to their proximity to the sea and availability of waterways for navigation.
- However, deltas have certain disadvantages compared to estuaries for port siting.
- Deltas are often characterized by shifting channels, sandbars, and sediment deposition, which can pose challenges for navigation and the maintenance of navigational channels.
- Deltas are also prone to frequent changes in their shape and size due to sedimentation and erosion, which can affect the long-term viability of port infrastructure.
- Estuaries, on the other hand, tend to have more stable and predictable water flows, making them more suitable for large port operations.
- Therefore, it is correct to say that deltas are less preferred sites than estuaries for the siting of large ports.
Conclusion:
- Both Statement 1 and Statement 2 are correct.
- Wind gaps in the course of a river indeed do not allow the construction of upland roads and railways due to their challenging topography.
- Deltas are less preferred sites than estuaries for the siting of large ports due to their dynamic nature and challenges associated with navigation and maintenance.
Explanation:
- Wind gaps are narrow passages or valleys in mountain ranges that are formed due to erosion by wind.
- These gaps are typically located in upland areas where rivers have cut through the mountain ranges.
- Due to their narrow and steep nature, wind gaps pose significant challenges for the construction of roads and railways.
- Constructing roads and railways in wind gaps would require extensive engineering efforts and may not be economically or technically feasible.
- The difficult topography, limited space, and high terrain make it challenging to create a stable and safe infrastructure in wind gaps.
- Therefore, it is correct to say that wind gaps in the course of a river do not allow the construction of upland roads and railways.
Statement 2: Deltas are less preferred sites than estuaries for the siting of large ports.
Explanation:
- Deltas are landforms formed at the mouth of a river where it meets a body of water, typically a sea or an ocean.
- Estuaries, on the other hand, are the areas where a river meets the sea and freshwater mixes with saltwater.
- Both deltas and estuaries are potential sites for the siting of large ports due to their proximity to the sea and availability of waterways for navigation.
- However, deltas have certain disadvantages compared to estuaries for port siting.
- Deltas are often characterized by shifting channels, sandbars, and sediment deposition, which can pose challenges for navigation and the maintenance of navigational channels.
- Deltas are also prone to frequent changes in their shape and size due to sedimentation and erosion, which can affect the long-term viability of port infrastructure.
- Estuaries, on the other hand, tend to have more stable and predictable water flows, making them more suitable for large port operations.
- Therefore, it is correct to say that deltas are less preferred sites than estuaries for the siting of large ports.
Conclusion:
- Both Statement 1 and Statement 2 are correct.
- Wind gaps in the course of a river indeed do not allow the construction of upland roads and railways due to their challenging topography.
- Deltas are less preferred sites than estuaries for the siting of large ports due to their dynamic nature and challenges associated with navigation and maintenance.
Consider the following about the rock systems of India: 1. The Archaean rocks are found in the Deccan Peninsula and parts of the North-east.2. The Dharwar rocks are rich in iron ore.Which of the above statements is/are correct? - a) 1 and 2 only
- b) 2 and 3 only
- c) 3 only
- d) 1 and 3 only
Correct answer is option 'A'. Can you explain this answer?
Consider the following about the rock systems of India:
1. The Archaean rocks are found in the Deccan Peninsula and parts of the North-east.
2. The Dharwar rocks are rich in iron ore.
Which of the above statements is/are correct?
a)
1 and 2 only
b)
2 and 3 only
c)
3 only
d)
1 and 3 only
|
Style's Star answered |
A) 1 and 2 only
Chapter doubts & questions for Geomorphology - Lucent For GK 2025 is part of UPSC CSE exam preparation. The chapters have been prepared according to the UPSC CSE exam syllabus. The Chapter doubts & questions, notes, tests & MCQs are made for UPSC CSE 2025 Exam. Find important definitions, questions, notes, meanings, examples, exercises, MCQs and online tests here.
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