2. What kind of landforms do you know?
How will you describe them?
How about the rocks that you see around?
Why do you think they vary in size, shape, an texture?
How do rocks change?
How do the changes in rocks affect the earth’s surface?
Answers to these questions will prove that the earth is
indeed made up of solid materials. Thus, it is amazing to
know that the earth’s surface also changes through time.
3. Scientific studies claim that the earth’s surface is
different from what it used to be hundreds of years ago.
The different landforms that you see now may be the
remains of larger structures in the past.
Some parts of the land may have been higher and more
rugged before that they are now.
Such changes could have been caused by various forces
present in nature, such as water, wind, heat, pressure,
and even living things.
These forces continuously shape the land by breaking
down or wearing away rocks.
4. SOIL
FORMATION
The whole soil, from the surface to its lowest depths,
develops naturally as a result of these five factors. The
five factors are:
1) parent material
2) relief or topography
3) organisms (including humans)
4) climate
5) time.
5. WEATHERING
-process of breaking rocks into pieces.
-three types:
a. Physical or mechanical weathering
b. Biological weathering
c. chemical weathering
6. A. PHYSICAL OR MECHANICAL
WEATHERING
rocks are broken down into smaller
pieces of rock called sediments.
It is caused by natural forces, such
as earthquakes, landslides, and
volcanic eruptions wherein rocks
break because of force.
7. B. BIOLOGICASL WEATHERING
is the weakening and subsequent disintegration of rock
by plants, animals and microbes.
Growing plant roots can exert stress or pressure on rock.
Although the process is physical, the pressure is exerted
by a biological process (i.e., growing roots). Biological
processes can also produce chemical weathering
, for example where plant roots or microorganisms
produce organic acids which help to dissolve minerals.
Example: rabbits and other burrowing animals can burrow into a
crack in a rock, making it bigger and splitting the rock. You may
have seen weeds growing through cracks in the pavement.
8.
9. B. CHEMICAL WEATHERING
>involves the exposure of rocks to
certain naturally occurring acids that
change these rocks into other
materials with new properties.
>rocks that are exposed to flowing
water, acid rain, and other naturally
occurring acids like sulfuric acid from
volcanic eruptions undergo
weathering.
10. SOIL EROSION
Soil erosion - is a process of moving soil by water or
wind - when the soil particles are detached and
transported to a different location. This is a natural
process that has occurred for eons of time. Water, wind,
ice, and gravity are involved in moving soil materials.
11. DIFFERENCE BETWEEN EROSION AND
WEATHERING
Erosion - refers to the displacement of the solids
through wind, water, and ice.
- refers to the decomposition of the
rocks, soil, and minerals through direct contact
with the atmosphere. The eroded materials are
displaced in the case of erosion.
