Question

The movements that give rise to mountains are called _________
A. Rapid movements
B. Epeirogenic movements
C. Orogenic movements
D. None of the above

Answer 1

Hint: It is horizontal movements of the earth's crust. It is a slow movement which happens over time. It can have both constructive and destructive results.

Complete Answer:
The Earth has many different types of geographic features all over it. These features have been built through various kinds of forces. There are different forces continually at work both at the surface level and below the surface of our planet. One of these forces are the main causes of the formation of mountains. Let us see what effects each of the forces have to find which is responsible for building mountains.

A. Rapid movements of the earth are sudden movements that are caused due to sudden release of pressure. The effects of these forces are very destructive and often result in loss of life and property. These do not cause formation of mountains. Therefore, this is not the right answer.

B. Epeirogenic movements are also known as continent building forces. They act along the radius of the Earth. They do not cause formation of mountains. At the most, they might form gentle sloping highlands. Therefore this is not the correct answer.

C. Orogenic movements, also called horizontal earth movements, are slow movements of the lithospheric plates. When two plates push against each other, it causes the stratas to fold upwards which causes formation of mountains. This process is also called orogenesis. Thus, this is the correct answer.

D. Since Orogenic movements cause formation of mountains, this is not the correct answer.

Therefore, the correct answer is Option C.

Note: Rapid movements usually result in disasters like volcanic eruptions, earthquakes, landslides etc. Epeirogenic forces are responsible for features like isostasy and faulting in the Earth's crust. Orogenic movements cause formation of both fold and block mountains as well as rift valleys. Orogenic movements may act over hundreds of years. For example, the Himalayas are young fold mountains where these forces are still active, which means that they might grow more taller over time.