Engineering Geology Multiple Choice Questions on “Classification of Folds – 01”.
1. The type of fold in which the limbs dip away from each other at the crest is ______________
a) Anticline
b) Syncline
c) Countercline
d) Doesn’t exist
Answer: a
Clarification: Anticlines are defined as those folds in which the limbs dip away from each other at the crest in the simplest forms.
2. The fold which is convex downwards is ___________
a) Anticline
b) Syncline
c) U-cline
d) Crestcline
Answer: b
Clarification: Synclines are the reverse of anticlines in all details and the strata are downarched, that is, these become convex downwards.
3. Which of the following is not true about Anticline?
a) The strata are uparched
b) Geologically older rocks occupy a position in the interior of the fold
c) The limbs dip away from each other at the crest
d) They are convex downwards
Answer: d
Clarification: Anticlines are said to convex upwards and not downwards. Synclines are convex downwards.
4. What is the other name for upright fold?
a) Symmetrical fold
b) Asymmetrical fold
c) Overturned fold
d) Isoclinal fold
Answer: a
Clarification: Symmetrical folds are also called normal folds or upright folds. In such a fold, the axial plane is essentially vertical.
5. Fold in which the limbs lie exactly one over another?
a) Isoclinal
b) Symmetrical
c) Recumbent
d) Asymmetrical
Answer: c
Clarification: In recumbent folds, one limb comes to lie exactly under the other limb so that a drill hole dug at the surface in the upper limb passes through the lower limb also.
6. Which of the following is also an overturned fold?
a) Isoclinal fold
b) Symmetrical fold
c) Asymmetrical fold
d) Recumbent fold
Answer: d
Clarification: Recumbent folds are described as extreme types of overturned folds in which the axial plane acquires an almost horizontal attitude.
7. Fold with flattened top is ___________
a) Square fold
b) Plateau fold
c) Box fold
d) Conjugate fold
Answer: c
Clarification: Box fold may be described as a special type of fold with exceptionally flattened top and steep inclined limbs almost forming three sides of a rectangle.
8. The type of fold in which fold angle is between 10° to 90°?
a) Tight fold
b) Loose fold
c) Gentle fold
d) Acute fold
Answer: a
Clarification: When it comes to fold angle as the basis of classification, the fold with a fold angle between 10° and 90° is called tight fold.
9. Which of the following is not a type of fold based on behaviour with depth?
a) Concentric fold
b) Similar fold
c) Supratenuous fold
d) Asymmetrical fold
Answer: d
Clarification: The first three options are the types based on behaviour with depth where asymmetric fold is based on position of axial plane.
10. Isogans converge inwards in class 1 folds.
a) True
b) False
Answer: a
Clarification: In class 1 folds, isogans converge inwards whereas in class 3, these converge upwards.
11. Where can folds be observed in the southern part of India?
a) Vindhyan region only
b) Satpura region only
c) Vindhyan and Satpura ranges
d) Cannot be observed in southern India
Answer: c
Clarification: Among the peninsular mountains, only the Vindhyan and the Satpuran ranges show folding in a prominent manner.
12. Where is the Liddar Valley Anticline situated?
a) Kashmir Himalayas
b) Uttarakhand Himalayas
c) Sikkim Himalayas
d) Himachal Pradesh Himalayas
Answer: a
Clarification: The Liddar Valley Anticline in Kashmir Himalayas is often represented as a classic example in that almost complete sequence of Palaeozoic Era is fully developed in this anticline.