Answer: d [Reason:] Sedimentary rocks especially those of plastic nature and rich in moisture in the initial stage (clays, shales, limestones, dolomites etc.) undergo some contraction on drying up which might have resulted into irregular jointing.

Answer: b [Reason:] During the formation of igneous rocks, tensile forces are developed in them due to cooling and the force is strong enough to cause joints. Such contraction or shrinkage is generally, accepted to be the cause of the vertical type of joints in granites and the so well -known columnar joints of basalts and other effusive rocks.

Answer: b [Reason:] Joints are caused in different rocks due to different reasons. No single theory can explain origin of all types of joints.

Answer: c [Reason:] Repeated expansion and contraction is characteristic of regions with dry hot (arid) climates where day and night temperatures on the one hand and summer and winter temperatures on the other hand vary within a very wide range of -50° to 60° C.

Answer: a [Reason:] Removal of overburden due to weathering or other processes of rock wasting may also cause expansion of the underlying rocks due to unloading. The previously loaded rocks get relaxed with the release of the forces.

Answer: b [Reason:] The sheet joints of sedimentary rocks and other rocks are attributed by many to the process of erosional unloading through geological ages.

Answer: d [Reason:] Joints affect the properties of rocks both in a negative as well as positive manner with respect to the activities of a professional civil and mining engineer.

Answer: d [Reason:] Many landslides and slope failures are directly related to the jointed nature of the rocks. This is due to instability of rocks in hilly regions and the jointed rocks get easily lubricated in presence of moisture and start sliding or falling from their places.

Answer: c [Reason:] Treating the negative qualities of rocks due to joints will differ in different projects. The first requirement in all cases is, however, detailed investigations to establish full characteristics of the joints.

Answer: c [Reason:] Great care has to be exercised in locating the presence, distribution patterns and magnitude of micro joints that are typical of many rocks. Such joints, if left unnoticed and untreated, may widen after the construction of the project and endanger its stability.

Answer: d [Reason:] As regards the positive effects of joints in rocks, these are greatly sought after in the exploration for groundwater and oil reserves in a given area. Only a well-jointed and porous rock can form a good aquifer or a good oil and gas reservoir.

Answer: a [Reason:] Mineralisation with economically valuable minerals from hydrothermal solutions takes place in jointed rocks and fissures, which are formed due to widening of joints.

Answer: a [Reason:] Ore mineral is defined as a mineral which contains a metallic element in a quantity that can be exploited and extracted for use at an economical cost.

Answer: b [Reason:] Natural concentration of an ore mineral in a massive rock body is defined as an ore deposit. Hence the definition of an ore deposit is also size dependent.

Answer: c [Reason:] A few non-metallic minerals are often found associated with an ore-mineral. These have be separated from the ore before the same is processed for extraction of the metal. These associated minerals are called gangue minerals.

Answer: b [Reason:] On the basis of their time of formation relative to the host rock, the ore deposits are divided into two groups: syngenetic and epigenetic.

Answer: a [Reason:] Syngenetic deposits are such deposits that have formed simultaneously with the enclosing rock. These are either of igneous or of sedimentary types.

Answer: b [Reason:] Epigenetic deposits are those deposits that were formed subsequent to the formation of the host rock. Epigenetic deposits of igneous, sedimentary and metamorphic types are known.

Answer: b [Reason:] Pegmatite deposits are sometimes classified as a distinct group of magmatic deposits formed towards the end of crystallization process and such necessarily occurring close to the roofs of magmatic masses.

Answer: c [Reason:] The three essential conditions for the formation of hydrothermal deposits are: highly active and enriched fluids, suitable pathways for their migration through the rocks, and suitable physic-chemical environment for their deposition to take place.

Answer: a [Reason:] Fissure-veins may be defined as mineral bodies of elongated or tabular shape deposited in pre-existing fissures. The original fissures may be parallel or intersecting, radial or fan-shaped in pattern and that is also the shape of the resulting ore bodies.

Answer: b [Reason:] Ladder-veins are commonly found in igneous rocks such as dykes and similar bodies and consist of transverse, roughly regularly spaced fractures that are filled with deposits of economic minerals.

Answer: d [Reason:] Gash-veins are narrow, sloping and thick-bodies deposits of minerals deposited in solution-fissures or cracks of the host rock which is generally a carbonate rock like limestone.

Answer: a [Reason:] Deluvial placers is the term used when gravity is the agency involved; such placers would be found along the foot hills and talus slopes.

Answer: d [Reason:] The term, stock works, is used for hydrothermal deposits that occur in veins or fissures of exceptionally small size, but in good number, within a limited space, traversing the body of rock profusely.

Answer: b [Reason:] Magmatic ore deposits commonly occur in the following forms: segregations, disseminations and injections.

Answer: c [Reason:] Folds may be defined as undulations or bends or curvatures developed in the rocks of the crust as a result of stresses to which these rocks have been subjected from time to time in the past history of the Earth.

Answer: d [Reason:] The folds may develop in any type of rock and may be of any shape and flexures.

Answer: b [Reason:] In general, folding is a ductile type of deformation experienced by the rocks compared to the brittle deformation where the rocks actually get broken and displaced when stressed.

Answer: a [Reason:] Folding is a very slow geological process and indicates an effort of the rocks in a particular environment to adjust themselves to the changing force fields operating on, within or around them.

Answer: d [Reason:] Parts of a fold include, limbs, hinge, axis of a fold, plunge of a fold and crest & trough. Height of fold is not referred as its part.

Answer: b [Reason:] An individual fold will have a minimum of two limbs but when the folds occur in groups, as this is common, a middle limb will be common to two adjacent folds.

Answer: a [Reason:] In a folded layer, a point can be found where curvature is maximum and one limb ends and the other limb starts from that point. This is the hinge point.

Answer: b [Reason:] Axis is a line and plunge is the angle which the line makes with a horizontal. A fold having a horizontal axis will obviously have a zero plunge.

Answer: a [Reason:] The line running through the highest points in an uparched fold defines the crest and similarly the line running through the lowest point in a downarched fold makes its trough. The crest and trough may or may not coincide with the axis of the fold.

Answer: c [Reason:] Axis of fold is defined as a line drawn parallel to the hinge line of a fold. In other words, line representing the intersection of the axial plane of a fold with any bed of the fold.

Answer: d [Reason:] The plunge is measured like dip of a bedding plane, both in terms of direction of plunge and degree of plunge.

Answer: b [Reason:] An axial plane is that imaginary plane that passes through all the points of maximum curvature in a folded sequence. It may be vertical, inclined or horizontal in nature.

Answer: a [Reason:] Limbs are the sides or flanks of a fold. The part labelled “A” in the figure is a limb of fold.

Answer: d [Reason:] An axial plane is defined as imaginary plane that passes through all the points of maximum curvature in a folded sequence. It may be vertical, inclined or horizontal. Also it can be either planar or non-planar.

Answer: c [Reason:] A mineral, is defined as, a naturally occurring inorganic solid substance that is characterized with a definite chemical composition and very often with a definite atomic structure.

Answer: d [Reason:] Mineralogy is the branch of geology dealing the wide range of aspects related to minerals like, their individual properties, mode of occurrence and mode of formation.

Answer: d [Reason:] A particular colour is produced by reflection of some and absorption of other components of white light.

Answer: d [Reason:] A mineral shows colour of that wavelength of the white light which is not absorbed by it by virtue of its composition and atomic structure.

Answer: a [Reason:] Idiochromatic having a characteristic, fairly constant colour related primarily to the composition of mineral. Metallic minerals belong to this category.

Answer: b [Reason:] Allochromatic minerals have a variable colour; the variety in colour is generally due to minute quantities of colouring impurities thoroughly dispersed in the mineral composition.

Answer: b [Reason:] Pseudochromatic minerals show false colour. Such an effect generally happens when a mineral is rotated in hand; it is then seen to show a set colours in succession.

Answer: a [Reason:] Many non-metallic minerals like quartz, calcite, fluorine, tourmaline etc. may occur in more than two colours depending on the nature of impurities.

Answer: d [Reason:] Psuodochromatism is attributed to simultaneous reflection and refraction from the mineral surface due to minute inclusions of impurities in the mineral at different locations.

Answer: c [Reason:] Some minerals may show rainbow colours either in their interior or on the exterior surface. This is called iridescence.

Answer: b [Reason:] Due to play of colours, the colours change in rapid succession on rotation and their effect is quite brilliant and appealing to the eye.

Answer: b [Reason:] The non-metallic minerals have low values of density, ranging between 2.5 and 4.5 g/cc, whereas metallic minerals and ores have densities as high as 20 g/cc.

Answer: a [Reason:] Minerals with atoms of greater atomic radii show less density values compared with those made of atoms of smaller atomic radii.

Answer: c [Reason:] Amorphous form is a form in which neither a crystal face nor a cleavage is seen. There is no evidence of orderly arrangement of atoms in this form.

Answer:a [Reason:] In some minerals an electric charge may be developed by heating. These are called pyroelectric minerals. Examples: Tourmaline, boracite, quartz etc.

Answer: b
Answer: In some minerals an electric charge is developed by applying pressure. This group is termed as piezo-electric. Examples: Tourmaline and quartz.

Answer: d [Reason:] A scale of fusibility has been suggested by Von Kobell. It consists of six minerals arranged according to temperature of fusion. Stibnite, Natrolite, Alamandine, Actinolite, Orthoclase and Bronzite.

Answer: a [Reason:] Since temperature and pressure are both known to change volume of substance, it follows that density will also show a change when a mineral is subjected to elevated temperature or high pressures.

Answer: a [Reason:] Only corundum can scratch topaz because, all the other minerals given have lesser Mohs number compared to topaz, whereas topaz as hardness number 8 and corundum has 9.

Answer: b [Reason:] It follows that the colour of a mineral may not be the same as its streak. For identification, streak is relied upon more than the colour of the mineral.

Answer: c [Reason:] Phosphorescence is similar to fluorescence in essential character but in this case light is emitted by mineral not during the act of exposure but after the substance is transferred rapidly to a dark place. Fluorite, quartz, willemite and diamond show this phenomenon.

Answer: b [Reason:] Vitreous lustre is a type of lustre which is typical of glass, ice etc. Example: Quartz.

Answer: c [Reason:] Silky lustre is like the shine of pure silk. Example: Gypsum.