As the part of Free NTA NET/KSET Test Series 2018 team StudyVillae providing the key answers. In this post we will be providing the key answers and explanations for the previous day test. The explanations are accurate and to the point. We recommend the aspirants to check their answers with key answers and revise accordingly.

This post has the key answer and explanations for the test GEO-101.

GEO-101 Key Answers

Q.1) Which of the following pairs are correctly matched?

i) Anticline : linear, strata normally dip toward axial center, youngest strata in center.

ii) Syncline : linear, strata normally dip away from axial center, oldest strata in center.

iii)Monocline : linear, strata dip in one direction between horizontal layers on each side.

iv)Recumbent : linear, fold axial plane oriented at low angle resulting in overturned strata in one limb of the                     fold.

Choose the correct answer from the codes given below

1. I, II, and III
2. II and III
3. III and IV
4. All the above

Q.1) Solution (3)

Fold types

Anticline: linear, strata normally dip away from axial center, oldest strata in center.

Syncline: linear, strata normally dip toward axial center, youngest strata in center.

Antiform: linear, strata dip away from axial center, age unknown, or inverted.

Synform: linear, strata dip toward axial centre, age unknown, or inverted.

Dome: nonlinear, strata dip away from center in all directions, oldest strata in center.

Basin: nonlinear, strata dip toward center in all directions, youngest strata in center.

Monocline: linear, strata dip in one direction between horizontal layers on each side.

Chevron: angular fold with straight limbs and small hinges

Recumbent: linear, fold axial plane oriented at low angle resulting in overturned strata in one limb of the fold.

Slump: typically monoclinal, result of differential compaction or dissolution during sedimentation and lithification.

Ptygmatic: Folds are chaotic, random and disconnected. Typical of sedimentary slump folding, migmatites and decollement detachment zones.

Parasitic: short wavelength folds formed within a larger wavelength fold structure – normally associated with differences in bed thickness

Disharmonic: Folds in adjacent layers with different wavelengths and shapes

Q.2) __________ are the result of complex folding mechanism caused by intense Horizontal movement and resultant compressive force and Both the limbs of a recumbent fold are parallel and horizontal.

1. Isoclinal folds
2. Nappes
3. Monoclinal folds
4. Symmetrical folds

Q.2) Solution (2)

Napes are the result of complex folding mechanism caused by intense Horizontal movement and resultant compressive force.

Both the limbs of a recumbent fold are parallel and horizontal. Due to further increase in the continued compressive force, one limb of the recumbent fold slides forward and overrides the other fold.

This process is called ‘thrust’ and the plane along which one part of the fold is thrust is called ‘thrust plane’. The up-thrust part of the fold is called overthrust fold.

Due to continuous compressive and horizontal movement, the broken limb of the fold is thrown several kilometers away from the original place. Such broken limb of the fold is called ‘nape’.

Q.3) Which of the following is not a graben?

1. Narmada Valley
2. Damodar Valley
3. Tapti Valley
4. Kashmir valley

Q.3) Solution (4)

Rift valley is a major relief feature resulting from faulting activities. Rift valley represents a trough, depression or basis between two crustal parts.

Rift valleys are formed due to displacement of crustal parts and subsidence of middle portion between two normal faults.

Rift valleys are generally also called as ‘graben’ which is a German word which means a trough-like depression

Rhine rift valley is the best example of a well-defined rift valley .

Death Valley in the southern California (USA) The floor of the Jordan rift valley and Death sea.

The Narmada valley, the Damodar valley and some stretches of the Son valley, the Tapti valley.

The central plain of Scotland, Spencer Bay of Australia, etc. are examples of rift valleys.

Kashmir Valley is formed due to folding not because of faulting.

Q.4) Which of the following rocks are called as parent rocks?

1. Igneous rocks
2. Metomorphic rocks
3. Sedimentary rocks
4. None

Q.4) Solution (1)

Igneous rocks are created from the cooling of molten magma/lava. All other rocks are derived from them, which is why you will also find them referred to as parent rocks on occasion.

Q.5) Sandstone is _________ sedimentary rock

1. Mechanically formed
2. Chemically formed
3. Organically formed
4. None

Q.5) Solution (1)

Mechanically formed or clastic sedimentary rocks are formed from the buildup of clatics: small pieces of fragmented rocks deposited as a result of mechanical weathering then lithified by compaction and cementation.

Examples of Clastic sedimentary rocks include sandstone, shale, siltstone, and breccias.

Q.6) Light House of the Mediterranean is

1. Vesuvius
2. Stromboli
3. Pelee
4. Kilimanjaro

Q.6) Solution (2)

Volcanoes of the Mediter­ranean region are mainly associated with the Alpine folds, e.g. Vesuvius, Stromboli (Light House of the Mediterranean) and those of the Aegean islands.

Q.7) _______ is the indirect Sources of information about the interior of earth

1. Deep earth mining
2. Drilling
3. Volcanic eruption
4. Meteors

Q.7) Solution (4)

Indirect Sources

Depth:

With depth, pressure and density increases and hence temperature. This is mainly due to gravitation.

Meteors:

Meteors and Earth are solar system objects that are born from the same nebular cloud. Thus they are likely to have a similar internal structure.

Gravitation:

The gravitation force (g) is not the same at different latitudes on the surface. It is greater near the poles and less at the equator. This is because of the distance from the center at the equator being greater than that at the poles.

The gravity values also differ according to the mass of material. The uneven distribution of mass of material within the earth influences this value. Such a difference is called gravity anomaly. Gravity anomalies give us information about the distribution of mass of the material in the crust of the earth.

Magnetic field:

The geodynamo effect helps scientists understand what’s happening inside the Earth’s core. Shifts in the magnetic field also provide clues to the inaccessible iron core. But their source remains a mystery.

Q.8) Which of the following is not the feature of primary waves?

1. Particles of the medium vibrate along the direction of propagation of the wave.
2. P-waves move faster and are the first to arrive at the surface.
3. They can travel in all mediums.
4. Also called as transverse or distortional waves.

Q.8) Solution (4)

Primary Waves (P waves)

• Also called as the longitudinal or compressional waves.
• Particles of the medium vibrate along the direction of propagation of the wave.
• P-waves move faster and are the first to arrive at the surface.
• These waves are of high frequency.
• They can travel in all mediums.
• Velocity of P waves in Solids > Liquids > Gases
• Their velocity depends on shear strength or elasticity of the material.

Option (4) is the feature of s-waves

Q.9) Given below are two statements, one labelled as Assertion (A) and other labelled as Reason (R). Select your answer from the codes given below:

Assertion (A): Weathering is a denudation process.

Reason (R): All the exogenic geomorphic processes are covered under a general term, denudation.

Codes:

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true, but (R) is not the correct explanation of (A).
3. (A) is true, but (R) is false.
4. (A) is false, but (R) is true

Q.9) Solution (1)

All the exogenic geomorphic processes are covered under a general term, denudation.

The word ‘denude’ means to strip off or to uncover.

Weathering, mass wasting/movements, erosion and transportation are included in denudation.

Q.10) _______ is the first step in the soil formation

1. Transportation
2. Weathering
3. Mass wasting
4. Vulcanism

Q.10) Solution (2)

Weathering is the first step in formation of soils.

Weathering of rocks and deposits helps in the enrichment and concentrations of certain valuable ores of iron, manganese, aluminium, copper etc.

Weathering helps in soil enrichment.

Without weathering, the concentration of the same valuable material may not be sufficient and economically viable to exploit, process and refine. This is what is called enrichment.

Q.11) ______ is used to measure the intensity of earthquake

1. Richter scale
2. Mercalli scale
3. Logarithm scale
4. Metric scale

Q.11) Solution (2)

The Mercalli intensity scale is a seismic intensity scale used for measuring the intensity of an earthquake. It measures the effects of an earthquake. It is distinct from the moment magnitude (Mw) usually reported for an earthquake, which is a measure of the energy released (sometimes misreported as the Richter magnitude, ML).

Q.12) Mahabaleshwar plateau is

1. Intermontane plateau
2. Piedmont plateau
3. Lava plateau
4. Dome plateau

Q.12) Solution (3)

Mahabaleshwar is the lava plateau. Located about 120 km (75 mi) southwest of Pune and 285 km (177 mi) from Mumbai, Mahabaleshwar is a vast plateau measuring 150 km2 (58 sq mi), bound by valleys on all sides.

Mahabaleshwar is the source of the Krishna River that flows across Maharashtra, Karnataka, Telangana and Andhra Pradesh.

Q.13) ________ is called as the roof of the world

1. Columbia – Snake Plateau
2. Tibetan plateau
3. Colorado Plateau
4. Deccan plateau

Q.13) Solution (2)

Tibetan Plateau

Highest and largest plateau in the world and hence called the ‘roof of the world’.

Formed due to collision of the Indo-Australian and Eurasian tectonic plates.

The plateau is sufficiently high enough to reverse the Hadley cell convection cycles and to drive the monsoons of India towards the south. [We will learn this in future posts]

It covers most of the Autonomous Tibetan Region, Qinghai Province of Western China, and a part of Ladakh in Jammu and Kashmir.

It is surrounded by mountains to the south by the Himalayan Range, to the northeast by the Kunlun Range, and to the west by the Karakoram Range.

Q.14) Reunion hotspot located in

1. Indian ocean
2. Pacific Ocean
3. Atlantic Ocean
4. Mediterranean Sea

Q.14) Solution (1)

Reunion Hotspot Volcanism

The Reunion hotspot is a volcanic hotspot which currently lies under the Island of Reunion in the Indian Ocean.

The Chagos-Laccadive Ridge (Lakshadweep is a part of this ridge) and the southern part of the Mascarene Plateau are volcanic traces of the Reunion hotspot.

The hotspot is believed to have been active for over 66 million years. A huge eruption of this hotspot 66 million years ago is thought to have laid down the Deccan Traps, a vast bed of basalt lava that covers part of central India and opened a rift which separated India from the Seychelles Plateau.

As the Indian plate drifted north, the hotspot continued to punch through the plate, creating a string of volcanic islands and undersea plateaus.

The Laccadive Islands, the Maldives, and the Chagos Archipelago are atolls resting on former volcanoes created 60-45 million years ago that subsequently submerged below sea level.

About 45 million years ago the mid-ocean rift crossed over the hotspot, and the hotspot passed under the African Plate.

The hotspot appears to have been relatively quiet from 45-10 million years ago, when activity resumed, creating the Mascarene Islands, which include Mauritius, Reunion, and Rodrigues.

Q.15) _________ has the highest density

1. Core
2. Crust
3. Mantle
4. Asthenosphere

Q.15) Solution (1)

Core

Lies between 2900 km and 6400 km below the earth’s surface.

Accounts for 16 per cent of the earth’s volume.

Core has the heaviest mineral materials of highest density.

It is composed of nickel and iron [nife].

The outer core is liquid while the inner core is solid.

A zone of mixed heavy metals + silicates separates the core from outer layers.

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