Geologic processes on Earth include exogenous and endogenous processes. Exogenous processes occur near the surface and include weathering, erosion, mass wasting, and sedimentation, which are driven by gravity, water, wind, and organisms. Endogenous processes occur within Earth and are driven by thermal energy in the mantle, resulting in magmatism, volcanism, metamorphism, and mountain building. While these processes shape the landscape and present risks, there may be no completely safe place, as all locations can be affected over millions of years.

1. GEOLOGIC PROCESSES ON
EARTH

2. EXOGENOUS PROCESSES
• Occur on or near the surface of
Earth
• Usually influenced or driven by
gravity, water, wind and
organisms
• In extreme cases, it can wipe out
majority of the organisms
inhabiting that area.

3. WEATHERING
• The disintegration of rocks, soil
and minerals together with other
materials through contact with
Earth’s subsystems
• Happens even without
movement or transportation

4. Physical Weathering
• Breakdown of rocks by mechanical
forces concentrated along rock
fractures
• Can occur due to changes in
temperature and pressure
• Example : soil cracks because of
extreme heat or drought
• In some cases, water, wind or ice may
scrape rocks or soil

5. Chemical Weathering
• Rocks break down by chemical reactions
• New or secondary minerals develop and
sometimes replace the original properties
of the minerals in the original rock or soil
• CONTRIBUTORS:
• OXIDATION – reaction of a substance with
oxygen
• HYDROLYSIS – the chemical breakdown of
a substance when combined with water
• ACID RAIN – may cause metals and stones
to corrode or deteriorate and change their
properties

6. EROSION
• Process by which earth’s surface is worn
away by wind, water, or ice
• Moves rock debris or soil from one place to
another
• Takes place when there is rainfall, surface
runoff, flowing rivers, seawater intrusion,
flooding, freeing and thawing, hurricanes,
wind, etc.
• Movement of land animals during migration
or stampede
• Human activities: deforestation, overgrazing
and mining

7. MASS WASTING
• Movement of large masses of materials
(rock debris, soil, mud) down a slope or
a steep sided hill or mountain due to
the pull of gravity
• Very destructive in areas with increased
water flow.
• DEBRIS FLOW
• MUDFLOW
• SLUMP

8. Mudflow
• Happens when combined soil and
water flow down a slope
• Usually happens near rivers or
streams where soil or sand is always
moist or has been soaked in water
for a long time.

9. Debris flow
Happens when a large amount of
sediments, usually rocks of various
sizes, falls down the slope.
Does not need water to flow down

10. Slump
• Slow movement of soil along a
curved surface.
• In time, the area would look curved
because of the depression formed by
the sinking land

11. SEDIMENTATION
• Accumulation of materials such as
soil, rock fragments and soil particles
settling on the ground.
• Usually occurs in streams or sea
erosion
• Over time, the sediment load
becomes thick and forms a new layer
of ground

13. • If geologic processes seem
to bring risk to human
safety, where then is a safe
place to live? Is there even
any?

14. ENDOGENOUS PROCESSES
• Takes place within or in the interior
of Earth.
• The driving force is the thermal
energy of the mantle.
• Responsible for earthquakes,
development of continents, mountain
building, volcanic activities, etc.

15. MAGMATISM
• Magma is the original material that
make up igneous rocks.
• Magmatism happens when a
magma is generated and develops
into igneous (magmatic) rocks
• The process can take place either
under the surface or on the surface
of Earth.

16. VOLCANISM (PLUTONISM)
• Process that usually happens after
the magma is formed.
• Magma tries to escape from the
source through openings such as
volcanoes or existing cracks on the
ground.
• As soon as magma reaches the
surface of the earth it is now called
lava.

17. METAMORPHISM
• Process of changing the materials that
make up a rock.
• Chemical components and geologic
characteristics of the rock changed due
to heat and pressure that are
increasing or decreasing.
• Note:
• Rocks changing due to weathering and
sedimentation are not considered to
have undergone metamorphism.

18. • What drives the endogenous
processes on Earth?
• Where does the force come
from?
• Why is it called
endogenous?