ALL ABOUT WEATHERING AND EROSION .. Weathering causes the disintegration of rock near the surface of the earth. Plant and animal life, atmosphere and water are the major causes of weathering. Weathering breaks down and loosens the surface minerals of rock so they can be transported away by agents of erosion such as water, wind and ice. There are two types of weathering: mechanical and chemical.

1. Weathering and Erosion

2. Weathering
• Weathering causes the disintegration of rock
near the surface of the earth. Plant and
animal life, atmosphere and water are the
major causes of weathering. Weathering
breaks down and loosens the surface minerals
of rock so they can be transported away by
agents of erosion such as water, wind and ice.
There are two types of weathering:
mechanical and chemical.

3. Types of weathering

4. Mechanical Weathering
Mechanical weathering is the disintegration of
rock into smaller and smaller fragments. Frost
action is an effective form of mechanical
weathering. When water trickles down into
fractures and pores of rock, then freezes, its
volume increases by almost 10 percent. This
causes outward pressure of about 30,000 pounds
per square inch at -7.6 Fahrenheit. Frost action
causes rocks to be broken apart into angular
fragments. Idaho's extreme temperature range in
the high country causes frost action to be a very
important form of weathering.

5. Chemical Weathering
Chemical weathering transforms the original
material into a substance with a different
composition and different physical
characteristics. The new substance is typically
much softer and more susceptible to agents of
erosion than the original material. The rate of
chemical weathering is greatly accelerated by
the presence of warm temperatures and
moisture. Also, some minerals are more
vulnerable to chemical weathering than
others. For example, feldspar is far more
reactive than quartz.
FIGURE : Chemical weathering of a statue,
caused by acid rain

6. Erosion
Once the small pieces of rocks are changed or
broken apart by weathering, they may start to
be moved by wind, water, or ice. When the
smaller rock pieces (now pebbles, sand or
soil)are moved by these natural forces, it is
called erosion.

7. Types of Erosion

8. Wind Erosion
• Wind erosion, though it may be small where
you live, can take quite a toll on areas of the
world covered in desert. Wind erosion is
simple... light objects, such as rocks and
pebbles are carried by the wind and can hit
landforms, eroding materials off them, that
are carried off in the wind.

9. Glacier Erosion
• Ice erosion, besides that of hail, comes mostly
in the form of glacier erosion. Glaciers are
giant bodies of ice that can pick up huge
pieces of rock, some even as big as houses. A
combination of the water, ice, and picked up
sediment, create a powerful eroding machine.

10. Soil Erosion
• Soil erosion pays the
biggest
price to farmers. Flooding,
wind etc.
can carry the topsoil away
from
farmlands, and make
the soil unfertile.

11. Erosion caused by rain or irrigation,
showing how
water can wash away the soil

12. Soil erosion caused by rain

13. Erosion by waves, forming a natural
bridge

14. Chemical weathering
causing minerals in
the
rocks to dissolve, and
then form stalactites
and stalagmites in a
cave.

15. Mechanical weathering called
exfoliation causing the rocks to break
into layers

16. REFERENCE
• http://www.doe.virginia.gov/instruction/gifte
d_ed/project_promise/science_curriculum/gr
ade_two/handouts/earth_science/weathering
_erosion_pictures.pdf
• http://imnh.isu.edu/digitalatlas/geo/basics/w
eathrng.htm
.http://www.odec.ca/projects/2004/derk4d0/pu
blic_html/differenttypesoferosion.htm

17. Made by
UROOJ AYAZ
VIII – B
BEACONHOUSE SCHOOL
All the information is used for
educational purpose only…..