Earth Science Exogenic Process

2. EXOGENIC PROCESSES
Are processes that
take place at or
near the earth’s
surface that
makes the surface
wear away.

3. These are very destructive.
They are responsible for
degradation and sculpting of
the earth’s surface.

4. TYPES OF EXOGENIC
PROCESSES
1. Weathering
2. Mass Wasting
3. Soil Erosion

6. WEATHERING
A process that cause rocks to
disintegrate physically or
decompose chemically
because of exposure to
elements of weather such as
temperature, rainfall, frost,
fog and ice.

7. In addition, the weathered
material lies at its original
position.
There is no transportation
or movement other than
gravity.

9. 1. PHYSICAL WEATHERING
Happens whenever rocks
are broken into smaller
fragments without any
chemical change in their
composition.

10. 1. PHYSICAL WEATHERING
a. Block disintegration
b. Exfoliation
c. Frost action
d. Abrasion

11. A successive heating and
cooling which causes the
expansion and contraction
of rocks.
A. BLOCK DISINTEGRATION

12. A. BLOCK DISINTEGRATION
In hot desert regions, day
temperatures are very high
while nights are very cold.
Because of these two
extremes, the rocks
disintegrate into smaller
blocks.

15. B. EXFOLIATION
This results because of the
intense heating of the
rock’s outer layers. Since
rocks are poor conductors
of heat, the inner layer
remain unaffected by heat.

16. Due to successive
expansion and
contraction, the outer
layers if the rock
subsequently peel off.

20. C. FROST ACTION
The alternate freezing
and melting of water
inside the joins of the
rocks, split them into
fragments.

21. C. FROST ACTION

25. D. ABRASION
is the mechanical scraping of
a rock surface by friction
between rocks and moving
particles during their
transport by wind, glacier,
waves, gravity, running water
or erosion.

27. Abrasion is the mechanical
scraping of a rock surface by
friction between rocks and moving
particles during their transport by
wind, glacier, waves, gravity,
running water or erosion.

33. 2. CHEMICAL WEATHERING
Gives way to formation of
new compounds or
formation of new
substances. Involves
chemical change.

34. TYPES OF CHEMICAL W.
2. Chemical Weathering
a. Oxidation
b. Carbonation
c. Hydration
d. Solution

35. A. OXIDATION
The process in which
atmospheric oxygen reacts
with the rock to produce
oxides. The greatest impacts
of this process is observed
on ferrous (iron) minerals.

39. B. CARBONATION
The process by which
various types of carbonates
are formed. Some of the
carbonates are soluble in
water.

40. 3.Carbonation – When pollutants like
Carbon Dioxide, Nitrogen & Sulfuric
Oxides mix with rain water creating
acid rain, which can dissolve limestone
and harm the living environment.
- Coal Burning For Electricity
- Fossil Fuel Consumption for Cars

44. When pollutants like CO2 &
SO2 mix with rain water
creating acid rain, which
can dissolve limestone and
harm the living environment.

45. C. HYDRATION
The process by which
water is absorbed by the
minerals of the rocks and
its volume increases and
the grains lose their shape.

46. C. HYDRATION

49. D. SOLUTION
The process in
which some of the
minerals
get dissolved in
water

51. 3. BIOTIC WEATHERING
a. Plants
b. Burrowing of Animals
c. Human Activity

52. A. PLANTS
The roots of the plants grow
longer and thicker. In this
manner they exert pressure
on rocks & the rock joins are
thereby enlarged & broken
into smaller fragments.

55. 2. BURROWING OF ANIMALS
Animals like earthworms,
rats, rabbits, termites & ants
breakdown the rocks. These
disintegrated rocks can
easily be eroded by wind,
etc.

56. 2. BURROWING OF ANIMALS
Animals like earthworms,
rats, rabbits, termites & ants
breakdown the rocks. These
disintegrated rocks can
easily be eroded by wind,
etc.

57. 2. BURROWING OF ANIMALS
Hooves of animals break the
rocks and thus assist soil
erosion.

58. 3. HUMAN ACTIVITIES
Man breaks a large amount
of rocks in the course of his
activities like agriculture,
construction and mining.

59. 3. HUMAN ACTIVITIES
Man breaks a large amount
of rocks in the course of his
activities like agriculture,
construction and mining.

61. WEATHERING FACTORS

63. SOIL EROSION
Is the removal
and transport of
soil at a greater
rate that its
replacement by
natural agencies
(water, wind,
etc.)

65. Carries dust, sand and volcanic
ash from one place to another.
Wind can sometimes blow
sand into towering domes.
Can erode the land in frigid areas
and on some mountaintops. As
the ice moves or melts, it pick up
everything in their path from tiny
grains of sand to boulders.
Gravity pulls any loose bits
down the side of a hill or
mountain.
Gravity erosion is also known as
Mass Movement.
Erosion by Water
Changes the shape of
coastlines.
Waves constantly crush against
shores. They pound rocks into
pebbles and reduce them to
sand.

67. Can erode the land in frigid areas
and on some mountaintops. As
the ice moves or melts, it pick up
everything in their path from tiny
grains of sand to boulders.
Gravity pulls any loose bits
down the side of a hill or
mountain.
Gravity erosion is also known as
Mass Movement.
Erosion by Wind
Carries dust, sand and
volcanic ash from one place to
another. Wind can sometimes
blow sand into towering
domes.

69. Gravity pulls any loose bits
down the side of a hill or
mountain.
Gravity erosion is also known as
Mass Movement.
Erosion by Ice
Can erode the land in frigid
areas and on some
mountaintops. As the ice
moves or melts, it pick up
everything in their path from
tiny grains of sand to
boulders.

71. Can erode the land in frigid areas
and on some mountaintops. As
the ice moves or melts, it pick up
everything in their path from tiny
grains of sand to boulders.
Erosion by Gravity
Gravity pulls any loose
bits down the side of a hill
or mountain.
Gravity erosion is also
known as
Mass Movement.

73. MASS MOVEMENT VIDEO (YouTube)

75. MASS WASTING
4
Mass Wasting refers to the
downslope movement of
rock and soil under the
influence of gravity.

76. This is a result of
Earth’s surface not
being flat but instead
consisting of slopes.

78. Mass Wasting is a natural
process and is considered
a natural hazard.
This process becomes
natural disaster when it
leads to loss of life &
property.

79. Controlled and triggered by
moisture (water) and
speed (rate).
The saturation of water
destroys the cohesion of
rock particles causing them
to loose.

80. TRIGGERS OF MASS WASTING

81. TYPES OF MASS WASTING
Based on the type of
motion, mass wasting could
be generally classified as
the following:

82. -Fall
-Slides
-Flow

83. 1.Fall – the free-fall
movement of detached
individual pieces of rocks.
2.Slides – occur whenever
rock materials remain fairly

84. 2.Slides – occur whenever
rock materials remain fairly
coherent and move along a
well-defined surface.

85. 3. Flow – when rock
materials are saturated with
water to move downslope
as a viscous fluid.