First Order Theories MCQ Quiz - Objective Question with Answer for First Order Theories - Download Free PDF

The correct answer is Tethys Sea.

Important Points

• India is a part of Gondwana land.
• Around 200 million years ago, the large landmass called Panagea started splitting into two large continental masses called Laurasia and Gondwana.
• Gondwana was a supercontinent.
• It existed from the Neoproterozoic period until the Jurassic period.
• Laurasia is a continental mass in the Northern Hemisphere.
• It includes North America, Europe, and Asia except peninsular India.
• The Tethys Sea was an ocean during the Mesozoic era.

Additional Information

• The Black Sea separates Europe and Asia.
• The Red Sea lies between Africa and Arabia.
• The pacific ocean extends from the Arctic Ocean in the North to the Southern Ocean in the South.

The correct answer is Alfred Wegener.

Key Points

• Alfred Wegener, a German meteorologist and geophysicist, proposed the Continental Drift Theory in 1912.
• He hypothesized that all continents were once joined together in a supercontinent called Pangaea, which gradually drifted apart.
• His theory was based on geological, paleontological, and climatological evidence, such as the matching coastlines of South America and Africa and the distribution of fossils.
• Despite being revolutionary, Wegener's theory faced criticism initially due to the lack of a plausible mechanism for continental movement.
• The Continental Drift Theory laid the foundation for the modern theory of plate tectonics, which was later established in the mid-20th century.

Additional Information

• Pangaea: The supercontinent hypothesized by Wegener that existed during the late Paleozoic and early Mesozoic eras.
• Plate Tectonics: A scientific theory developed later in the 20th century explaining the movement of Earth's lithospheric plates driven by mantle convection.
• Fossil Evidence: Similar fossils of extinct plants and animals, such as Mesosaurus, were found on continents now separated by oceans, supporting Wegener's theory.
• Geological Evidence: Matching rock formations and mountain ranges across continents, such as the Appalachian Mountains in North America and the Caledonian Mountains in Europe.
• Criticism of Wegener's Theory: Early opposition stemmed from the lack of an explanation for the forces driving continental movement, which was later addressed by the theory of plate tectonics.

The correct answer is Option 2

Key Points

• Both (A) and (R) are true, and (R) is the correct explanation of (A).

• Assertion (A): The Himalayas are still rising. (True)

  • The Himalayas are still growing in height because of the continuous tectonic movement.

  • Studies show that the mountain range rises by a few millimeters each year due to geological forces.

• Reason (R): The Indian tectonic plate is colliding with the Eurasian plate. (True)

  • The Indian Plate is moving northward and continuously colliding with the Eurasian Plate at a rate of about 5 cm per year.

  • This ongoing collision causes uplift and deformation, leading to the rise of the Himalayas.

• Why is Option (2) Correct?

  • The reason (R) correctly explains the assertion (A) because the collision of tectonic plates is the primary cause of the continuous rise of the Himalayas.

The correct answer is option 2.

Key Points

• The Cocos Plate is located between Central America and the Pacific Plate. It is a young oceanic tectonic plate beneath the Pacific Ocean off the west coast of Central America.
• The Nazca Plate is located between South America and the Pacific Plate. It is an oceanic tectonic plate in the southeastern Pacific Ocean basin, and it is responsible for the Andes mountain range.
• The Arabian Plate comprises mostly the Saudi Arabian landmass. It is a tectonic plate in the northern and eastern hemispheres, including the Arabian Peninsula.
• The Philippine Plate is located between the Asiatic and Pacific Plates. It is an oceanic tectonic plate that lies beneath the Philippine Sea to the east of the Philippines.

 Additional Information

• Arabian Plate
  • The Arabian Plate includes the countries of Saudi Arabia, Yemen, Oman, UAE, Qatar, and parts of Jordan and Iraq.
  • This plate is moving northward, causing the collision with the Eurasian Plate which contributes to the uplift of the Zagros mountains in Iran.
• Philippine Plate
  • The Philippine Plate is characterized by subduction zones and has high seismic activity.
  • The interaction of the Philippine Plate with the Eurasian Plate forms the Philippine Trench, a major subduction zone.

Key Points

• Basalt is an extrusive igneous rock, which forms when lava cools rapidly on the Earth's surface, leading to the formation of fine-grained rocks.
• Granite is an intrusive igneous rock, not extrusive. It forms from the slow cooling of magma beneath the Earth's surface, resulting in coarse-grained textures.
• Hence, the correct answer is option 1.

The correct answer is Tethys Sea.

Important Points

• India is a part of Gondwana land.
• Around 200 million years ago, the large landmass called Panagea started splitting into two large continental masses called Laurasia and Gondwana.
• Gondwana was a supercontinent.
• It existed from the Neoproterozoic period until the Jurassic period.
• Laurasia is a continental mass in the Northern Hemisphere.
• It includes North America, Europe, and Asia except peninsular India.
• The Tethys Sea was an ocean during the Mesozoic era.

Additional Information

• The Black Sea separates Europe and Asia.
• The Red Sea lies between Africa and Arabia.
• The pacific ocean extends from the Arctic Ocean in the North to the Southern Ocean in the South.

The Correct Answer is Gondwana.

• The Indian Peninsular was a part of Gondwana land.
• The Peninsular plateau is the oldest landmass as it was formed due to the breaking and drifting of the Gondwana land. 
• The plateau consists of two broad divisions: The Central Highlands and The Deccan Plateau.
• The part of the peninsular plateau lying to the north of the Narmada River, covering a major area of the Malwa plateau, is known as the Central Highlands.
• The triangular landmass that lies to the south of the river Narmada is known as Deccan Plateau.
• Gondwana Land consists of Antarctica, South America, Africa, Madagascar, India, Arabia, Australia-New Guinea, and New Zealand.

The correct answer is Nazca plate.

Key Points 

• Tectonic Plates
  • A tectonic plate (also called a lithospheric plate) is a massive, irregularly-shaped slab of solid rock, generally composed of both continental and oceanic lithosphere.
  • The lithosphere includes the crust and top mantle with its thickness range varying between 5-100 km in oceanic parts and about 200 km in the continental areas.
  • The concept of Tectonic Plates was first introduced in 1967.
  • A tectonic plate may be a continental plate or an oceanic plate, depending on which of the two occupies the larger portion of the plate.
  • The Pacific plate is largely an oceanic plate whereas the Eurasian Plate is a continental plate.

Additional Information

• The Major and Minor Plates
  • The Earth’s lithosphere is divided into seven major and some minor plates.
  • Young Fold Mountain ridges, oceanic trenches, and/or transform faults surround the major plates. These include:
  • The Antarctic (and the surrounding oceanic) plate
  • The North American plate (with the western Atlantic floor separated from the South American plate along with the Caribbean islands)
  • The South American plate (with the western Atlantic floor separated from the North American plate along with the Caribbean islands)
  • The Pacific plate
  • The India-Australia-New Zealand plate
  • Africa with the eastern Atlantic floor plate
  • Eurasia and the adjacent oceanic plate
• Some important minor plates include:
  • Cocos plate: Between Central America and the Pacific plate
  • Nazca plate: Between South America and the Pacific plate
  • Arabian plate: Mostly the Saudi Arabian landmass
  • Philippine plate: Between the Asiatic and Pacific plate
  • Caroline plate: Between the Philippine and Indian plates (North of New Guinea)
  • Fuji plate: North-east of Australia
  • Juan De Fuca plate: South-East of North American Plate.
• Hence, Option 1 is correct.

The statement 4 is not correct.

Key Points

Seismic Wav  es (Earthquake Waves)

• Seismic waves are waves of energy caused by earthquakes or an explosion. They are the energy that travels through the earth and is recorded on seismographs.
• Earthquake waves are basically of two types — body waves and surface waves.
• Body waves are generated due to the release of energy at the focus and move in all directions traveling through the body of the earth. Hence, the name body waves.
• There are two types of body waves. They are called P and S-waves.
  • P-waves move faster and are the first to arrive at the surface. Hence, Statement 1 is correct.
  • These are also called ‘primary waves’. 
  • The P-waves are similar to sound waves. 
  • They travel through gaseous, liquid, and solid materials. Hence, Statement 2 is correct.
  • P-waves are also called the longitudinal waves.
  • The seismographs located beyond 145° from epicenters; record the arrival of P-waves, but not that of S-waves. Hence, Statement 2 is correct.
  • P-waves create density differences in the material leading to stretching (rarefaction) and squeezing (compression) of the material.
  • S-waves arrive at the surface with some time lag. These are called secondary waves.
  • An important fact about S-waves is that they can travel only through solid materials. 

Important Points

• There exist some specific areas where the waves are not reported. Such a zone is called the ‘shadow zone’.
• A zone between 105° and 145° from the epicenter was identified as the shadow zone for both the types of waves.
• The shadow zone of S-wave is much larger than that of the P-waves.
• The shadow zone of S-waves is not only larger in extent but it is also a little over 40 percent of the earth's surface. Hence, Statement 4 is not correct.

The correct answer is Option 3.

Key Points

• In the seafloor spreading process, there is a gradual addition of new oceanic crust in the ocean floor through volcanic activity while moving the older rocks away from the mid-oceanic ridge.
• It is the result of mantle convection.
• It occurs at divergent plate boundaries.
• Seafloor spreading theory was proposed by an American geophysicist, Harry H. Hess.
• Facts considered as evidence in the proposition of seafloor spreading theory are the following:
  •  Magnetic stripes on the rocks,
  • Radiometric age dating of rocks and fossil ages,
  • Conventional current theory,
  • Seafloor mapping,
  • Volcanic activity along the mid-oceanic ridges.
• There was no discussion over the distribution of fossils in rocks found on different continents. Hence, option 3 is incorrect. 

The correct answer is Antarctica.

Key Points

• A tectonic plate is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere.
• They are also called lithospheric plates.
• Depending on the occupied area of the plate, it is classified as an oceanic plate or continental plate.
  • If a large portion of the plate occupies the ocean it is called an Oceanic plate.
  • If a large portion of the plate occupies the continent it is called a continental plate.
• The Earth's lithosphere is divided into seven major and some minor plates. 
• Major Plates:
  • Antarctica and surrounding oceanic plates
  • North American Plate
  • South American Plate 
  • Pacific Plate
  • India-Australia-New Zealand Plate
  • Africa with the eastern Atlantic floor plate
  • Eurasia and the adjacent oceanic plate
• Minor Plate:
  • Cocos Plate - It is found Between Central America and the Pacific plate
  • Nazca plate - It is found between South America and the Pacific plate
  • Arabian Plate - It is found in Saudi Arabian landmass
  • Philippine Plate - It is found between the Asiatic and Pacific plate
  • Caroline Plate - It is found between the Philippine and India Plate that is North of Guinea
  • Fuji Plate - It is found in the North-East of Australia

The correct answer is All of the Above.

Key Points

Evidence that supports the theory:

• The Matching of Continents (Jig-Saw-Fit): 
  • The shorelines of Africa and South America facing each other match remarkably.
• Rocks of Same Age Across the Oceans: 
  • Radiometric dating methods have correlated the rock formation in different continents.
• Tillite: 
  • ​The glacial tillite found in the Gondwana system of sediments has its resemblance to six different landmasses of the Southern Hemisphere.
• Placer Deposits: 
  • The placer deposits of gold in the Ghana coast do not have source rock in the region. 
  • The gold deposits of Ghana have been derived from the Brazil plateau when the two continents lay side by side
• Distribution of Fossils: 
  • Identical species of plants and animals adapted to living on land or in freshwater are found on either side of the marine barriers.

Important Points

Continental Drift Theory:

• Alfred Wegener put forward a continental drift theory in 1912.  
• All the continents are formed of a single Continental mass and a mega ocean surrounded the same.
• The supercontinent was named Pangaea and the Mega Ocean was called Panthalassa.  
• Pangea first broke into two large Continental masses Laurasia and  Gondwanaland Forming the northern and Southern components respectively. 
• Laurasia and Gondwanaland continued to break into smaller continents that existed today.  ​

The correct answer is Mantle.

Key Points

• A convection current is a process that involves the movement of energy from one place to another.
• It is also called convection heat transfer.
• Convection Current is defined as “a process of continuous heating up of liquids or gases by the process called convection. 
• The Earth's crust is broken up into pieces called plates.
• The crust moves because of movements deep inside the earth.
• Heat rising and falling inside the mantle creates convection currents generated by radioactive decay in the core. Hence Option 2 is correct.
• The convection currents move the plates.
• Where convection currents diverge near the Earth's crust, plates move apart.
• Where convection currents converge, plates move towards each other.
• The movement of the plates, and the activity inside the Earth, is called plate tectonics.
• Plate tectonics causes earthquakes and volcanoes.
• The point where two plates meet is called a plate boundary.
• Earthquakes and volcanoes are most likely to occur either on or near plate boundaries. 

The correct answer is ​the theory of plate tectonics.

Key Points

• The theory that states "pieces of the Earth's crust are in constant, slow motion driven by movement in the mantle" is called Plate Tectonics.
• Plate tectonics is a scientific theory that explains the movement of the Earth's lithospheric plates, which make up the Earth's outer shell.
• These plates float on the semi-fluid asthenosphere beneath them and are driven by the convective currents in the mantle.
• This theory helps explain the formation of continents, ocean basins, earthquakes, volcanic activity, and the interactions of tectonic plate boundaries.

Additional Information

•  The theory of plate tectonics is a comprehensive scientific theory that explains the movement of the Earth's lithospheric plates, which make up the Earth's outer shell.
• The theory is composed of several key ideas:
• Lithospheric Plates: The Earth's rigid outer layer, known as the lithosphere, is divided into several large and small plates that "float" on the semi-fluid asthenosphere beneath them. 
• Plate Boundaries: The edges of these plates are the most dynamic regions on Earth. There are three primary types of plate boundaries:
  • Divergent Boundaries: At divergent boundaries, plates move away from each other. This can lead to the formation of new oceanic crust through seafloor spreading and the creation of rift valleys on continents.
  • Convergent Boundaries: At convergent boundaries, plates move toward each other. When two plates collide, it can result in subduction, where one plate is forced beneath the other, leading to the formation of deep ocean trenches, volcanic arcs, and mountain ranges.
  • Transform Boundaries: At transform boundaries, plates slide past each other horizontally. The friction and pressure along these boundaries can lead to earthquakes.
• Seafloor Spreading: Harry Hess and Robert Dietz's work in the mid-20th century contributed to the understanding of seafloor spreading. This process occurs at mid-ocean ridges, where new oceanic crust is formed as magma rises and solidifies.
• Plate Interactions: The interactions of these plates result in various geological features, including the formation of mountain ranges, volcanic activity, earthquakes, and the distribution of continents and oceans.

The correct answer is option 3, i.e. Harry Hess.

• Harry Hess proposed the theory of SeaFloor Spreading in 1961.
• He stated that new lava pushes out the plates from the mid-oceanic ridge.
• Paleomagnetic studies of the ocean floor reveal that there is an intense volcanic eruption and the huge amount of lava is coming out along the mid-Atlantic ridges.
• The equidistant rock formation has similar age, magnetic properties and chemical compositions.
• Rocks which are closer to the mid-oceanic ridges are young having normal polarity.
• Oceanic crust is much younger than continental crust.
• The ocean floor is very thin.
• He said that the new plate is created at the divergent boundary and the older plate is destroyed at the convergent boundary.