Engineering Geology Multiple Choice Questions on “Valleys”.
1. A depression or hollow of considerable area extent surrounded on the side by two or more elevated tracts is called __________
a) Valley
b) Mountain
c) Pit
d) Crest
Answer: a
Clarification: A valley, in the geomorphic sense, is a depression or hollow of considerable area extent surrounded on side by two or more elevated tracts. Valleys may be the result of age-long erosion along the medial parts of elevated tracts, or, these might have been produced from a gradual or abrupt subsidence.
2. The type of valley most common on Earth is __________
a) Rain valleys
b) Erosional valleys
c) Wind valleys
d) Tectonic valleys
Answer: b
Clarification: The erosional valleys are the most common types of valleys on the Earth. Erosional valleys may be the result of the stream erosion and glacial erosion. They are accordingly named as River valleys and Glacial valleys.
3. The river valleys are typically of which shaped sections?
a) C-shaped
b) D-shaped
c) V-shaped
d) O-shaped
Answer: c
Clarification: A river valley is the result of down-cutting and bank erosion by the river. Since most of the river erosion processes are concentrated along the bottom of a river channel, especially in the mountainous regions, the resulting river valley has a typical V-shaped cross-section.
4. What is the weathering of the exposed walls by physical and chemical processes followed by slippage of weathered products into river below under the action of gravity called?
a) Mass slipping
b) Mass wasting
c) Rocks wasting
d) Debris wasting
Answer: b
Clarification: Weathering of the exposed walls by physical and chemical processes followed by slippage of weathered products into river below under the action of gravity and rainwash, the process is called mass wasting.
5. The modification of valley walls by undercutting, weathering and erosion is called __________
a) Incision
b) Deposition
c) Denudation
d) Enudation
Answer: c
Clarification: Incision is the down-cutting along the base of the channel by the river itself and denudation is the modification of valley walls by undercutting, weathering and erosion.
6. The type of valley formed when incision is a major process and denudation is almost absent is __________
a) Saw cut valleys
b) V-shaped valleys
c) Flat-floored valleys
d) Glacial valleys
Answer: a
Clarification: Saw cut valleys arise when incision is the major process and denudation is either absent or negligible. A very narrow, almost vertical-walled valley is produced.
7. Deep saw cut valleys with slightly opened up tops indicating some denudation are specially referred as __________
a) Canyons
b) Canons
c) Gorges
d) Gorgeous
Answer: c
Clarification: Exceptionally deep saw cut valleys with slightly opened up tops indicating some denudation are specially referred to as Gorges. These are quite common and impressive features of the major Himalayas Rivers in their mountainous tracts.
8. Types of gorges where the strata involved in down cutting is essentially horizontal or nearly so are called __________
a) Canyon
b) Gorgeian
c) Flicklops
d) Lockiles
Answer: a
Clarification: Canyons are those types of gorges where the strata involved in down cutting is essentially horizontal or nearly so. The Grand Canyon of Colorado is a well-known example.
9. The valleys which are V-shaped are always symmetrical.
a) True
b) False
Answer: b
Clarification: The V-shaped valleys may be said to have established a broad equilibrium between the down cutting, slope-denudation and their load carrying capacity. The valleys may or may not be symmetrical in their transverse profile depending upon the type of rocks on the slopes.
10. The type of valley formed when the incision and denudation are approximately equal __________
a) Saw cut valleys
b) V-shaped valleys
c) Flat-floored valleys
d) Glacial valleys
Answer: b
Clarification: In the formation of V-shaped valleys, the incision and denudation are approximately equal. In such cases, the valley profile assumes a typical V-shape.
11. Valleys in which the incision becomes negligible and denudation of slopes is major process are __________
a) Saw cut valleys
b) V-shaped valleys
c) Flat-floored valleys
d) Glacial valleys
Answer: c
Clarification: When the incision becomes negligible and denudation of slopes is the major process, the result is a flat-floored valley. It is the common profile of a valley in the lower reaches of a river.
12. Depending upon the extent of incision and denudation occurred during the formation of a valley, how many broad classes of valleys are present?
a) 2
b) 4
c) 3
d) 5
Answer: c
Clarification: The nature of the valley profile at any section in the course of a river depends on the ratio Incision: Denudation operating in that section. Three broad cases may be considered. Saw cut valleys; V-shaped valleys and flat-floored valleys.