weathering 
The rocks break into small 
pieces like it is called 
weathering. As this action 
continues, the size of the 
rocks reduces and makes 
way for soil formation.
As a result of weathering, rocks 
disintegrate and becomes small 
pieces and when the organic content 
mix with this, in course of time, soil is 
formed. For the formation of one 
inch of soil, it takes about a thousand 
or more years.
Weathering is mainly of 
three types 
•Mechanical weathering 
•Chemical weathering 
•Biological weathering
Mechanical weathering 
Changes in 
temperature and the 
freezing of the water in 
the cracks of the rocks 
cause mechanical 
weathering.
Changes in temperature 
Rocks expand due to the heat of the 
sun. the different minerals in the 
rocks expand in different 
magnitudes, on these rocks if 
suddenly rain falls or at night
Freezing of water in the 
cracks in rocks 
• During the day, the heat of the sun causes the 
snow to melt and water fills the cracks in the 
rocks. At night when the temperature drops to 
below freezing point, the water in these cracks 
freezes and becomes ice.
Exfoliation 
During the day, the rocks become 
heated and expand with the rays 
of the sun and at night the 
temperature decreases, they 
contract, this alternate expansion 
and contraction causes the other 
surface of the rocks to break into 
layers. This kind of peeling away 
of rock layers is called exfoliation.
Chemical weathering 
• When the rain falls on 
the rocks chemical 
action takes place 
between the minerals in 
the rocks and the rain 
water. As a result of this, 
there can be 
disintegration of the 
rocks. This is called 
chemical weathering.
Biological weathering 
The roots of the trees 
penetrate into the cracks 
of the rocks and small 
creatures make their 
homes in these spaces. 
These also cause the 
disintegration of rocks. 
This is called biological 
weathering.

Sha

  • 1.
    weathering The rocksbreak into small pieces like it is called weathering. As this action continues, the size of the rocks reduces and makes way for soil formation.
  • 2.
    As a resultof weathering, rocks disintegrate and becomes small pieces and when the organic content mix with this, in course of time, soil is formed. For the formation of one inch of soil, it takes about a thousand or more years.
  • 3.
    Weathering is mainlyof three types •Mechanical weathering •Chemical weathering •Biological weathering
  • 4.
    Mechanical weathering Changesin temperature and the freezing of the water in the cracks of the rocks cause mechanical weathering.
  • 5.
    Changes in temperature Rocks expand due to the heat of the sun. the different minerals in the rocks expand in different magnitudes, on these rocks if suddenly rain falls or at night
  • 6.
    Freezing of waterin the cracks in rocks • During the day, the heat of the sun causes the snow to melt and water fills the cracks in the rocks. At night when the temperature drops to below freezing point, the water in these cracks freezes and becomes ice.
  • 7.
    Exfoliation During theday, the rocks become heated and expand with the rays of the sun and at night the temperature decreases, they contract, this alternate expansion and contraction causes the other surface of the rocks to break into layers. This kind of peeling away of rock layers is called exfoliation.
  • 8.
    Chemical weathering •When the rain falls on the rocks chemical action takes place between the minerals in the rocks and the rain water. As a result of this, there can be disintegration of the rocks. This is called chemical weathering.
  • 9.
    Biological weathering Theroots of the trees penetrate into the cracks of the rocks and small creatures make their homes in these spaces. These also cause the disintegration of rocks. This is called biological weathering.