Earth and Life Science - 11 Module 5

1. EXOGENIC
PROCESS

2. Exogenic Process
Also called Exogenic Geomorphic Processes
Processes occurring on the Earth's surface
and that generally reduce relief.
These processes include weathering and the
erosion, transport, and deposition of soil and
rocks; the primary geomorphic agents driving
exogenic processes are water, ice, and wind.

3. Weathering
refers to the process of disintegration
and decomposition of rocks.
is the breaking down or dissolving of
rocks and minerals on Earths surface.
is an important process in the formation
of soil.
 is a mixture of grains,
organic matter, H2O, and
gas.

4. Two types of Weathering
•Physical
Weathering
•Chemical
Weathering

5. Physical or Mechanical
Weathering
is the
breakdown of
rocks into
pieces without
any change in
its composition.

6. Factors the causes physical or mechanical
weathering
• Pressure
• Temperature
• Frost Wedging
• Abrasion
• Organic Activity
• Human
Activities
• Burrowing
Animals

7. 1. Pressure
Due to tectonic forces,
granite may rise to
form mountain range.
After the granite
ascends and cools, the
overlying rocks and
sediments may erode.

8. 2. Temperature
Rocks expand and are fractured
when expose to high temperature.

9. 3. Frost Wedging
Generally, rocks have
fracture in its surface
and when water
accumulates in the
crack and at that point
freezes, the ice
expands and breaks
the rock apart.

10. 4. Abrasion
The breakdown of
rocks is caused by
impact and
friction.

11. 5. Organic Activity
The roots grow
causing
penetration into
the crack, expand,
and in the long
run, break the
rock.

12. 6. Human Activities
Activities such as
digging, quarrying,
denuding forests
and cultivating land
contribute to
physical
weathering.

13. 7. Burrowing Animals
Animals like rats, rabbits and
squirrels excavate into the ground to
create a space for habitation.

14. Chemical
Weathering
are changes in the
composition of rocks
due to the chemical
reactions.

15. Types of Chemical Reactions
1. Dissolution
2. Hydrolysis
3. Oxidation

16. 1. Dissolution
It occurs in specific
minerals which are
dissolved in water.
Examples:
Halite (NaCl)
Calcite (𝐶𝑎𝐶𝑂3).

17. 2. Hydrolysis
Rock-forming
minerals like
amphibole,
pyroxene, and
feldspar react
with water and
form different
kinds of clay
minerals.

18. 3. Oxidation
It is the response of
oxygen with
minerals. If the iron
oxidizes, the
mineral in rocks
decomposes.

19. Erosion
is the separation and removal of
weathered rocks due to different
agents that causes transportation
of the material to where they are
deposited.

20. •Wind •Glacier •Water
Different Agents of Erosion

21. Deposition
is the laying down of sediment
carried by wind, flowing water, the
sea or ice.

22. Transport
refers to the processes by which
the sediment is moved along.
Example:
• pebbles rolled along a river-bed or
seashore,
• sand grains whipped up by the wind,
• salts carried in solution.