Give an account of the work of wind. [V. Imp.]
Wind is an active agent of erosion and deposition in the deserts. In deserts we often notice rocks in the shape of a mushroom, known as mushroom rocks. Winds erode the lower section of the rock more than the upper part. Therefore, such rocks have narrower base and wider top. When the wind blows, it lifts and transports sand from one place to another. When the wind stops blowing the sand falls and gets deposited in low hill-like structures. These are called sand dunes. When the grains are very fine and light, the wind can carry it over long distances. When such sand is deposited in large area, it is called loess.
Answer the following questions briefly:
(i) Why do the plated move?
(ii) What are exogenic and endogenic force?
(iii) What is erosion?
(iv) How are flood plains formed?
(v) What are sand dunes?
(vi) How are beaches formed?
(vii) What are ox-bow lakes?
Give reasons:
(i) Some rocks have a shape of a mushroom.
(ii) Flood plains are very fertile.
(iii) Sea caves are turned into stacks.
(iv) Buddings collapse due to earthquakes.
Activity
Observe the photographs given below. These are various features made by a river. Identify them and also tell whether they are erosional or depositional or landforms formed by both.
