21. A rock composed entirely of crystals is called:

(a) Holohyaline

(b) Holocrystalline

(c) Monocrystalline

(d) Cryptocrystalline

Answer: (b)

22. The process of transformation of glass to crystalline matter is known as:

(a) Devitrification

(b) Recrystallization

(c) Verification

(d) Prettification

Answer: (a)

23. Which one of the following is the converse of porphyritic texture?

(a) Panidiomorphic texture

(b) Hypidiomorphic texture

(c) Poikilitic texture

(d) Felsitic texture

Answer: (c)

24. The subaerial and submerged contiguous sediment mass deposited in the body of water, ocean or lake is termed:

(a) Delta

(b) Lacustrine

(c) Alluvial fan

(d) Eolian

Answer: (a)

25. Froude number is used to express behavior of particles when the fluid is moving. It is essentially:

(a) Measure of flow in open channel

(b) Ratio of the force of inertia and acceleration due to gravity

(c) Settling time of high density particles

(d) Ratio of high density particles and density of water

Answer: (b)

26. According to the Walther’s law of facies (faciesbezirk):

(a) A conformable vertical sequence of facies was generated by vertical sequence of environment

(b) A conformable lateral sequence of facies can correlated with vertical sequence of environment

(c) A non-conformable sequence of facies can correlated with small lateral continuity

(d) A conformable vertical sequence of facies was generated by a lateral sequence of environments

Answer: (d)

27. ‘Smectite’ is a group of mineral with three-layer lattice structure, the unusual property of these minerals is:

(a) Chemically very stable

(b) Ooze out water in contact with sun light

(c) Expanding and contracting to adsorb or lose water

(d) Break into cubical form during the process of natural disintegration

Answer: (c)

28. ‘Gossan’ is a term that is used to describe:

(a) The uppermost weathered layer of sulphide ores composed of residual silica and limonite

(b) Reprecipitated ores of copper and lead

(c) Roll front deposit of uranium

(d) Residual deposits of alumina

Answer: (a)

29. Rocks with consistent tectonic, metamorphic, magmatic and chronologic features are typical of Proterozoic terrains are referred as:

(a) Precambrian shield

(b) Mobile belts

(c) Tectono metamorphic

(d) Archean belt

Answer: (b)

30. How a pyroclastic process involves explosive aerial ejection from a vent?

(a) Explosions are caused by near surface trapped boiling magma, often groundwater heated by underlying magma body explodes

(b) Pyroclastic material called tephra cause explosion

(c) Explosive ejection is caused due to forceful injection

(d) Juvenile magnetic fragments cause explosion, and in turn caprocks are exploded

Answer: (a)