2. Difference between weathering and erosion
•Weathering involves
disintegration and
decomposition of
rocks.
•It is a static process.
•It is important for
soil formation.
•Erosion wears and tears
away the rocks and
transports the eroded
materials.
•It is a dynamic process.
•It is a destructive
process.
3.
4. Types of weathering
•A. Mechanical weathering.
•B. Chemical weathering.
•C. Biological weathering.
5. Mechanical weathering
•Disintegration of rocks due to elements of
weather such as frost, wind, plants, man
and animals.
•It depends on the following factors:
•Extremes of temperature, nature of
rocks, structure of rocks, frost, wind and
slope of the land.
6. Extremes of temperature
• In arid and semi arid regions due to intense
heat of day time the rock gets expanded and
during night due to cool temperature the rock
gets contracted. Due to this repeated process
the rocks become weak and gets disintegrated.
In some cases the rocks peel-off layer by
layer resulting in a rounded structure of rock
and we call it as exfoliation.
8. Nature of rocks
•Some rocks may be hard and some be
soft.
•Mechanical weathering takes place in soft
rocks.
•Eroded materials are easily lifted by wind.
9. Structure of rocks.
•Vertically arranged layers of rocks are
more susceptible to weathering than the
horizontally arranged layers.
10. Frost
•Most common agent of weathering in
temperate regions.
•Water enters into cracks, turns into ice
and the volume increases.
•During the day ice thaws and water
enters deep into rocks.
•Repeated process results in breaking of
rocks.
13. Slope of land
•Steep slopes of rocks
are eroded more rapidly
than the gentle slopes.
14. Homework to be written in c.w
•Answer the following questions.
•1. What is meant by exfoliation?
•2. Describe the action of frost in weathering
of rocks.
•3. Differentiate between weathering and
erosion.
