Geography · General Awareness

Geology and Earth Structure

1,345 Questions

Geology and Earth Structure explores the physical composition of the planet, including its layers, tectonic plates, and seismic activity. This topic is a core component of geography and general science sections in various competitive exams. Reviewing these concepts builds a solid foundation for answering questions related to natural phenomena.

Layers of the EarthTectonic PlatesEarthquakes and VolcanoesGeomagnetism ApplicationsGeophysical MethodsLandform Formation

Geology and Earth Structure Questions

Multiple choice

Consider the following statements associated with the Deccan Traps:

  1. From the Cretaceous to the Eocene, intense volcanic activity took place in Peninsular India.
  2. The volcanic lava spread out horizontal sheets, filling the irregularities of the pre-existing topography.
  3. The trap country is characterized by conical hills and extensive flat surfaces. Of these statements:

  1. 1 and 2 are correct

  2. 1, 2 and 3 are correct

  3. 2 and 3 are correct

  4. 1 and 3 are correct
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Deccan Traps were formed by volcanic eruptions between the Cretaceous and Eocene periods, resulting in horizontal lava sheets. While the landscape features flat-topped plateaus and step-like slopes (traps), it is not characterized by conical hills, which are typical of different volcanic or erosional processes.

Multiple choice

Earthquakes along the Himalayas and the foothills are best explained in terms of

  1. plate tectonics

  2. young age of the Himalayas

  3. fragile and largely unconsolidated rocks

  4. divergence of plates

Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Himalayas are formed by the ongoing collision between the Indian Plate and the Eurasian Plate. This plate tectonic activity causes significant seismic stress, leading to frequent earthquakes along the mountain range and its foothills.

Multiple choice

Moho-discontinuity is found between the

  1. crust and mantle

  2. upper mantle and lower mantle

  3. mantle and core

  4. inner core and outer core
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Mohorovicic discontinuity, commonly called the Moho, is the boundary layer that separates the Earth's crust from the underlying mantle. It is identified by a sharp increase in the velocity of seismic waves.

Multiple choice

Consider the following statements regarding earthquakes:

  1. In earthquakes, shocks are generated at a point known as the epicentre
  2. The point of origin of shock may be within the crust or mantle
  3. The more earthquake-prone areas are the margin of tectonic plates Which of the above statements are correct?

  1. 1, 2 and 3

  2. 1 and 2

  3. 1 and 3

  4. 2 and 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

Statement 1 is incorrect because the point of origin within the Earth is the focus (hypocenter), while the epicenter is the point on the surface directly above it. Statements 2 and 3 are correct as earthquakes can originate in the crust or upper mantle and are most frequent at tectonic plate boundaries.

Multiple choice

The development of synclinal ridges and anticlinal valleys in a folder region is named as

  1. Parallel belt of valleys and ridges

  2. Abrasion platform

  3. Topograph of inversion of relief

  4. Ridge and valley landscape
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

In folded mountain regions, differential erosion can lead to 'inversion of relief' where synclines form ridges and anticlines form valleys. This results in a characteristic ridge and valley landscape, often seen in the Appalachians.

Multiple choice

Which of the following statements are true?

  1. Moderate earthquakes are caused along constructive plate boundaries.
  2. Low magnitude earthquakes are caused along constructive plate boundaries.
  3. Disastrous earthquakes are caused along destructive caused boundaries.
  4. Severe earthquakes are caused along the conservative plate boundaries with the creation of transform faults. Select the correct answer using the codes given below

  1. 1 and 2

  2. 1 and 3

  3. 1, 3 and 4

  4. 2, 3 and 4
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Earthquake intensity varies by plate boundary: constructive (divergent) boundaries typically have low-to-moderate magnitude shallow earthquakes, while destructive (convergent) boundaries produce the most disastrous, high-magnitude events. Conservative (transform) boundaries also produce severe earthquakes due to lateral shearing.

Multiple choice

Match List I with List II and select the correct answer: List I (Theories/Hypothesis) A. Geosynclinal Theory B. Tetrahedral hypothesis C. Stationary Wave Theory D. Subsidence Theory List II (Hypothesis regarding origin of the earth)

  1. Origin of tides
  2. Origin of coral reefs and atolls
  3. Mountain building
  4. Origin of continents and ocean basin

  1. A 3 B 4 C 2 D 1

  2. A 4 B 3 C 2 D 1

  3. A 3 B 4 C 1 D 2

  4. A 4 B 3 C 1 D 2
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Kober's Geosynclinal Theory explains mountain building. Lowthian Green's Tetrahedral hypothesis explains the distribution of continents and oceans. Harris's Stationary Wave Theory explains tides. Darwin's Subsidence Theory explains the origin of coral reefs.

Multiple choice

Which one of the following is a third-order relief?

  1. Abyssal

  2. Cliffs

  3. Plateau

  4. Trench
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

First-order relief features are continents and ocean basins, while second-order features include mountains and plateaus. Third-order relief features are small-scale landforms like cliffs, valleys, and dunes that are carved into larger features by erosion and deposition.

Multiple choice

Hawaii Island are known for active volcanoes because

  1. They are locked in the subduction zone of the covering plates

  2. faults and fractures are found there

  3. They are situated over a hot plume

  4. they are situated on a mild oceanic ridge with rising convective currents
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

The Hawaiian Islands are a classic example of hotspot volcanism, where a stationary plume of hot mantle material rises through the middle of a tectonic plate. As the Pacific Plate moves over this plume, a chain of volcanoes is created.

Multiple choice

Consider the following statements in relations to Earth`s topmost layer:

  1. Transverse earthquake waves moves at a speed of 3.5 km/second in that layer.
  2. The specific gravity is 2.7.
  3. It is shallowest under Continents and deepest under Oceans.
  4. Abundance of magnesium. Which of the above statements are correct

  1. 1 and 2

  2. 2 and 3

  3. 3 and 4

  4. 1, 2 and 4
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

In the upper crust (Sial), S-waves travel at approximately 3.5 km/s and the average specific gravity is 2.7. Statement 3 is false because the crust is thickest under continents and thinnest under oceans; statement 4 is false because the top layer is rich in aluminum (Sial), while magnesium (Sima) is dominant in the lower layer.

Multiple choice

Match the List I with List II and select the correct answer? List I (Technical Terms) List II (Definition) A. Magma Chamber 1. A point on earths surface where impact of the arthquake is felt maximum B. Epicentre 2. An opening in the earths crust Through which magma flows Out C. Vent 3. A point below the earths surface where the earthquake originates D. Seismic Focus 4. A place below the earths surface where lawa is formed and act as a source of magma outflow

  1. A 3 B 1 C 2 D 4

  2. A 3 B 2 C 1 D 4

  3. A 4 B 2 C 1 D 3

  4. A 4 B 1 C 2 D 3
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The magma chamber is the underground source of lava (4). The epicentre is the surface point directly above the focus where shaking is strongest (1). The vent is the conduit for magma to reach the surface (2). The seismic focus (hypocentre) is the actual point of origin underground (3).

Multiple choice

Consider the following statements:

  1. A tectonic scrap is steel slope that results from differential movement of the earth`s surface.
  2. The typical angel of repose for scraps of all origins is between 25o to 40o.
  3. A scrap produced by structurally controlled erosion at an ancient fault is known as fault-line scrap.
  4. A capable fault is one that shows movement at or near the ground surface at least once within the past 35,000 years. Which of the above statements are correct?

  1. 1, 2, 3, and 4

  2. 2, 3, and 4

  3. 1 and 3

  4. 2 and 3
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Statements 1 and 3 correctly define tectonic scarps and fault-line scarps. Statement 2 is incorrect because the angle of repose varies significantly by material and origin, and statement 4 is often defined by different timeframes (e.g., 10,000 or 35,000 years) depending on the specific regulatory body, but 1 and 3 are the most universally accepted geomorphic definitions here.

Multiple choice

Rift valleys came into existence due to ________.

  1. warping

  2. faulting

  3. magma

  4. none of these
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

Rift valleys are formed when the earth's crust is pulled apart, leading to the formation of faults. The land between these parallel faults sinks down to create a long, narrow valley. This process is a result of tectonic forces rather than simple warping or volcanic activity.

Multiple choice

Consider the following statements in relation to Earth’s topmost layer:

  1. Transverse earthquake waves move at a speed of 3.5 km/s in that layer.
  2. The specific gravity is 2.7.
  3. It is shallowest under continents and deepest under oceans.
  4. Abundance of magnesium.

Which of the above statements are correct?

  1. 1 and 2 only

  2. 2 and 3 only

  3. 3 and 4 only

  4. 1, 2 and 4 only
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

The Earth's topmost layer (crust) has a specific gravity of about 2.7 and transverse earthquake waves (S-waves) travel through it at approximately 3.5 km/s. It is thickest under continents and thinnest under oceans, making statement 3 incorrect.