The Earth's Structure and Processes

1. What could be the reason why
rocks varies in size, shape and
texture?

2. Weathering and
Erosion
Presented by: Arjohn Dave T. Amarila

3. Earth during the Ice Age Era

4. Scientific studies claim that earth’s
surface is different from what it is used
to be hundreds of years ago.

5. Different landforms today maybe the remains of larger
structure in the past.
Some may had been higher than before and more
refuged than they are now.
So what causes this CHANGES?

6. Changes could have been caused by
various forces present in nature, such as;
WATER, WIND, HEAT, PRESSURE and
even LIVING THINGS.

7. Weathering- a process by which rock is broken into
pieces by destructive forces.
Two types of weathering:
Mechanical Weathering
Chemical Weathering

8. Mechanical Weathering- caused by natural
forces (earthquakes, landslides & volcanic
eruptions)
Rocks broken down into small pieces called
sediments

9. Chemical Weathering- caused by naturally
occurring acids (flowing water, acid rain,
sulfuric acid)
Exposure to acids may lead the rocks in
changing its properties.

10. Agents of Weathering
Effects of
weathering are
clearly observed
whenever a rock
is exposed to the
environment.

11. Water
The strong current of these
water systems can push boulders
and stones and carry away rocks
and soil along their courses.
Crashing waves can break
rocks off cliffs and way
shorelines.
River, streams and
wave action

12. When carbon dioxide from the air dissolves in rainwater,
it forms carbonic acid in a process called carbonation.
Carbonic acids reacts with minerals, such as iron,
calcium and magnesium.
These compound easily dissolve with water and erode
rocks quickly.
Water

13. Water and temperature is one of the most
important means of weathering.
Frost Weathering- freezing of water in the
cracks of big rocks. This process forces the rocks
to break off.

14. Abrasion- wind carrying grains of
sand on rock surfaces.
Wind

15. Root wedging- roots entering
small cracks in rocks.
As it grow bigger it wedge apart the
rocks.
Trees

16.  can crumble the big
rocks
 can exposed the deeply
buried rocks on the
surface.
Animals

17. Effect of Weathering
Very important in the production of soil
Produces LOOSE SOIL (product of
continuous weathering.
Serves as habitat mostly of all living things.
Used for establishment
Soil

18. Excessive weathering results in the
loosening of rocks and soil which are
easily removed and carried away by
natural forces/agents.
Erosion

19. Erosion carries weathered sediments and
eventually deposited and settled in a new place.
Sediments can either be as pebbles, sand, mud
or salt dissolved in water.
Deposition
Missouri River (Mud River)

20. Agents of Erosion
Wind, water, and even animals can transport
eroded materials to a new locations.
(pebbles, sand and dust)

21. Effects of Erosion
Weathering and Erosion are considered as
destructive forces because they can dramatically
change and reshape the land.
 Natural activity, but can cause harm to living
things.

22. Thank You For
Listening  