Category: Engineering Geology Objective Questions

Engineering Geology Multiple Choice Questions on “Occurrence of Joints”.

1. Tensile stresses in igneous rocks are developed during ___________
a) Cooling
b) Crystallisation
c) Cooling and crystallisation
d) Molten state
Answer: c
Clarification: The igneous rocks are formed by cooling and crystallisation of hot molten material called magma or lava. As such, in most cases they show joint systems related to the tensile stresses developing during the process of cooling and crystallisation.

2. The type of regular joint not belonging to igneous rocks is?
a) Sheet jointing
b) Box jointing
c) Mural jointing
d) Columnar jointing
Answer: b
Clarification: The three regular or systematic types of joints observed in igneous rocks are: sheet joints, mural joints and columnar joints.

3. Which jointing gives layered sedimentary structure appearance?
a) Sheet jointing
b) Mural jointing
c) Box jointing
d) Columnar jointing
Answer: a
Clarification: In granites and other related igneous rocks, a horizontal set of joints often divides the rock mass in such a way as to give it an appearance of a layered sedimentary structure, called in this case as a sheeting structure.

4. Sheet joints are caused not due to ___________
a) Consequence of loading
b) Weathering
c) Removal of overlying rock mass
d) Consequence of unloading
Answer: a
Clarification: Sheet joints are sometimes caused due to weathering and removal of overlying rock masses, which cause expansion of the underlying igneous and other rocks as a consequence of unloading.

5. The geometrical distribution where rock mass is divided into cubes is ___________
a) Sheet jointing
b) Mural jointing
c) Columnar jointing
d) Radial jointing
Answer: b
Clarification: Mural jointing is a sort of geometrical distribution of joints dividing the rock mass into cubical blocks or murals and hence the name.

6. Types of joint found in volcanic igneous rocks are?
a) Sheet joints
b) Mural joints
c) Columnar joints
d) Radial joints
Answer: c
Clarification: Columnar joints are typical of volcanic igneous rocks although they may also be observed in other rocks.

7. Columnar joints are also called ___________
a) Radial joints
b) Pyramid joints
c) Prismatic joints
d) Box joints
Answer: c
Clarification: Columnar joints are also called as prismatic joints. The joints divide the rock mass into polygonal blocks each block being bounded by three to eight sides.

8. How are the main joints aligned to the cooling surface?
a) Perpendicular
b) Parallel
c) At 45°
d) At 30°
Answer: a
Clarification: Normally, the main joints are vertical or perpendicular to the cooling surface and may extend to varying depths ranging a few centimetres to many metres.

9. How and what are the polygonal cracks related to?
a) Directly related to compressive forces
b) Directly related to tensile forces
c) Inversely related to tensile forces
d) Directly related to shearing forces
Answer: b
Clarification: The polygonal cracks are thought to be directly related to the tensile forces developed during cooling (accompanied by contraction) of hot molten material (lava).

10. The contraction is equally developed in all directions in which kind of mass?
a) Non-homogenous
b) Isotropic
c) Anisotropic
d) Homogenous
Answer: d
Clarification: In a homogenous mass undergoing uniform cooling throughout the surface, contraction is equally developed in all directions.

11. At what angle do the fractures appear to the lines of tensile stresses?
a) 180°
b) 90°
c) 45°
d) 60°
Answer: b
Clarification: When the strength of the rock is overcome, fractures appear at right angles to the lines of tensile forces.

12. In sedimentary rocks, joints are genetically related to those forces that have caused the major structural deformation.
a) True
b) False
Answer: a
Clarification: Since sedimentary rocks are often folded and faulted, the joints in them are genetically related to those forces that have caused the major structural deformations.

13. Joints in metamorphic rocks are due to ___________
a) Indirect stresses
b) Local stresses
c) Regional stresses
d) Local and regional stresses
Answer: d
Clarification: The metamorphic rocks types are heavily jointed in many cases, the joints being of irregular or non-systematic types. These joints are often the result of local and regional stresses acting on rocks as a source of metamorphism.

14. In mural jointing, one set is horizontal and two sets are vertical.
a) True
b) False
Answer: a
Clarification: In granitic and other rock masses, there may occur three sets of joints in such a way that one set is horizontal and the other two sets are vertical, all the three sets being mutually perpendicular to each other.

Engineering Geology Questions and Answers for Campus interviews on “Forms of Igneous Rocks – 02”.

1. The intrusive bodies in which injection of lava occurs without any influence of dip and strike is ______________
a) Concordant bodies
b) Discordant bodies
c) Non-cordant bodies
d) Uncomformities
Answer: b
Clarification: All those intrusive bodies that have been injected into the strata without being influenced by their structural disposition (dip and strike) and thus traverse across or oblique to the bedding planes etc. are grouped as discordant bodies.

2. The example not belonging to discordant body is ______________
a) Dykes
b) Volcanic necks
c) Bysmaliths
d) Batholiths
Answer: c
Clarification: Bysmalith is a type of laccolith which is again a type of concordant body and not a discordant body. The dykes, volcanic necks and batholiths are usually the widely studied types of discordant bodies.

3. Which discordant body is columnar or column shaped?
a) Dykes
b) Volcanic necks
c) Bysmaliths
d) Batholiths
Answer: a
Clarification: Dykes may be defined as columnar bodies of igneous rocks that cut across the bedding plane or uncoformities or cleavage planes and similar structures.

4. Texture shown by dykes is ______________
a) Equigranular
b) Directive
c) Intergrowth
d) All types of textures
Answer: d
Clarification: In composition, dykes are generally made up of hypabyssal rocks like dolerites, porphyrites and lamprophyres, showing all textures between glassy and phaneritic types.

5. Dykes tend to occur individually.
a) True
b) False
Answer: b
Clarification: Dykes generally tend to occur in groups or sets. Thus, the term dyke-set is used for a couple of parallel and closely spaced dykes.

6. When the vents of quiet volcanoes become sealed with intrusions it leads to ______________
a) Dyke
b) Batholith
c) Extrusion
d) Volcanic necks
Answer: d
Clarification: In some cases, vents of quiet volcanoes have become sealed with the intrusions. Such congealed intrusions are termed volcanic necks or volcanic plugs.

7. The bodies which show both concordant and discordant relations are ______________
a) Dykes
b) Sills
c) Batholiths
d) Phacoliths
Answer: c
Clarification: Batholiths are huge bodies of igneous masses that show both concordant and discordant relations with the country rocks.

8. What should be the area and depth respectively, for an igneous body to be called a batholith?
a) 100 square km and depth not traceable
b) 10 square km and depth up to 100km
c) Not traceable and depth 10 km
d) 50 km and depth 10 km
Answer: a
Clarification: The dimensions of batholiths vary considerably but it is generally agreed that to qualify as a batholith the igneous mass should be greater than 100 square kilometres in area and its depth should not be traceable.

9. What is the term used for a batholith when surface area is less than 100 km?
a) Dykes
b) Stock
c) Sock
d) Sillets
Answer: b
Clarification: When the surface area of batholith-like igneous mass is less than 100 km, it is commonly termed as stock. When such a stock has a roughly circular outline, it is further distinguished as a boss.

10. Majority of batholiths show which composition?
a) Felsitic
b) Granitic
c) Ophitic
d) Directive
Answer: b
Clarification: In composition, batholiths may be made of any type of igneous rock. They also exhibit many types of textures and structures. But as a matter of observation, majority of batholiths shows predominantly granitic composition, texture and structure.

11. Pick the wrong statement about granitization.
a) It is a set of processes rather than a single step
b) It involves already existing sedimentary and other rocks
c) It involves magmatic stage
d) It doesn’t actually require magmatic stage
Answer: c
Clarification: Granitization may be broadly described as a set of processes by which already existing sedimentary and other rocks are changed into granit-like without actually passing through a magmatic stage.

12. The volcanic sheets may vertical.
a) True
b) False
Answer: b
Clarification: The volcanic sheets may be horizontal or slightly inclined depending upon the original topography and subsequent geological history of the area.

Engineering Geology for Campus Interviews,

Basic Engineering Geology Questions and Answers on “Mineral Resources of India – 02”.

1. Asbestos is a fibrous variety of ___________
a) Chrysotile
b) Cristile
c) Christile
d) Christine
Answer: a
Clarification: The common asbestos is actually a fibrous variety of mineral Chrysotile-hydrous silicate of magnesium.

2. The amphibole varieties are found in which state?
a) Karnataka
b) Bihar
c) Orissa
d) Rajasthan
Answer: d
Clarification: The amphibole varieties anthophyllite and tremolite, are produced in Udaipur and Durgapur districts.

3. Which mineral is used in paints, rubber textiles?
a) Asbestos
b) Barytes
c) Corundum
d) Quartz
Answer: b
Clarification: The mineral Baryte finds use in paints, rubber textiles and also in oil well drilling muds besides in chemical industry.

4. Which state produces largest amount of barytes?
a) Kerala
b) Andhra Pradesh and Telangana
c) Karnataka
d) Orissa
Answer: b
Clarification: Andhra Pradesh is presently the largest producer of barytes in our country. The mineral occurs in limestones spread over districts of Kuddapah, Kurnool and Anantapur.

5. The pure variety of corundum is __________
a) Emerald and ruby
b) Ruby and Sapphire
c) Sapphire and diamond
d) Ruby and Coral
Answer: b
Clarification: A high grade natural abrasive- corundum. The mineral finds use in grinding wheels. Its pure varieties form gems- the ruby and sapphire.

6. Dolomite is not used for/as __________
a) Flux
b) Refractory material
c) Source in special cements
d) Precious gemstones
Answer: d
Clarification: Dolomite is carbonate rock of wide occurrence in India and elsewhere and also with wide applications as a flux in metallurgy, as a refractory material and as source material in special cement.

7. Which mineral is used in manufacture of Sorel cement?
a) Dolomite
b) Magnesite
c) Manganese
d) Iron
Answer: b
Clarification: Magnesite is one of the important refractory materials. Other uses of magnesite include in the manufacture of a special cement called Sorel cement, in chemical industry and also as a source of metal magnesium.

8. Mica is of which origin?
a) Igneous
b) Sedimentary
c) Metamorphic
d) Erosional
Answer: a
Clarification: The mica mineral is of an igneous origin and commonly occurs in pegmatites in the form of thick sheets and masses.

9. Gypsum commonly occurs as a mineral of which origin?
a) Primary
b) Secondary
c) Tertiary
d) Quarternary
Answer: b
Clarification: Gypsum commonly occurs as a mineral of secondary origin associated with other sedimentary formations in the form of intervening layers, stringers and extended beds.

10. The only producer of diamond in India is __________
a) Rajasthan
b) Madhya Pradesh
c) Bihar
d) Orissa
Answer: b
Clarification: In India, diamonds have been produced only in Madhya Pradesh from the well-known Panna diamond mines. Here the mineral occurs in volcanic pipes mixed with primary magmatic rocks and also from the conglomerate deposits around the hill.

To practice basic questions and answers on all areas of Engineering Geology,

Engineering Geology Multiple Choice Questions on “Types of Dams – 02”.

1. How many types of arch dams are present?
a) 1
b) 3
c) 4
d) 2
Answer: d
Clarification: Two main types of arch dams are: The constant radius arch dam and the variable radius dam.

2. The type of arch dam in which upstream face is vertical is __________
a) Constant radius arch dam
b) Variable radius arch dam
c) Vertical arch dam
d) Inclined arch dam
Answer: a
Clarification: The constant radius arch dam is an arch dam in which the radius of curvature throughout the structure is constant and upstream face is vertical.

3. An arch dam having a curvature both in horizontal and vertical alignment is called __________
a) Constant radius arch dam
b) Variable radius dam
c) Cupola
d) Cipalo
Answer: c
Clarification: An arch dam having a curvature both in horizontal and vertical alignment is often called a cupola dam.

4. Pick the wrong statement about arch dams.
a) Arch dams are heavier compared to other types
b) Arch dams offer many advantages over other dams
c) Arch dams are quite thin walled compared to gravity dams
d) Arch dams are lighter in weight compared to other types
Answer: a
Clarification: In ideal situation, arch dams offer many advantages over other types of dams. Arch dams are quite thin walled compared to gravity dams and hence lighter in weight.

5. Arch dams are best suitable for which site?
a) Flat lands
b) Plateaus
c) Narrow valleys
d) Very wide valleys
Answer: c
Clarification: Arch dams are better suited for narrow valleys with strong and uniformly sloping walls or abutments.

6. The arch dam in India is situated in which state?
a) Karnataka
b) Gujarat
c) Kerala
d) Maharashtra
Answer: c
Clarification: The Idukki dam in Kerala is an important arch dam of our country.

7. The dam which generally is of trapezoidal shape is __________
a) Gravity dams
b) Arch dams
c) Cupola dams
d) Embankment dams
Answer: d
Clarification: Embankment dams include a variety of non-rigid structures which are built over wide valleys with varying foundation characteristics from easily available materials such as earth and rock fragments. These are generally of trapezoidal shape.

8. The dam which can be constructed even on glacial deposits is __________
a) Gravity dams
b) Arch dams
c) Embankment dams
d) Cupola dams
Answer: c
Clarification: The main advantage of the embankment dams is that they can be constructed on weak foundations such as unconsolidated weak-river or glacial deposits.

9. The Hirakud dam in India is which type of dam?
a) Gravity dams
b) Arch dams
c) Cupola dams
d) Embankment dams
Answer: d
Clarification: The Hirakud dam in Orissa is one of the longest embankment dams of our country.

10. The compacted core is generally made of __________
a) Shale
b) Clay
c) Limestone
d) Coal
Answer: b
Clarification: An embankment dam is constructed as a homogeneous construction but very commonly, with a properly compacted core of impervious material such as clay.

11. An arch dam cannot be constructed at all when the valley is very wide.
a) True
b) False
Answer: b
Clarification: A combination of series of arch dams called Multiple Arch Dams is sometimes applied with an advantage when the valley is too wide for a single arch or gravity dam. Hence, arch dam can be constructed in a very wide valley too.