Download Weathering - Thomas C. Cario Middle School




Vocabulary
Weathering: The breakdown of rocks or
minerals into smaller pieces by mechanical or
chemical means.
Announcements:
 7.EC25A.2
 Construct explanations of how soil quality (including
composition, texture, particle size, permeability)
affects the characteristics of an ecosystem using
evidence from soil profiles.


7.4.3
Describe natural processes that change Earth’s
surface Interactions among changes in the
environment due to natural hazards (including
landslides, earthquakes, mountain building, new land
being formed, weathering, erosion, sedimentation,
soil formation).


Weathering is
simply the
breakdown of rock
into smaller pieces.
Weathering can
occur by chemical
or mechanical
(physical) means.
WEATHERING


The simple
breakdown of rock
in to smaller pieces.
The result of
weathering is soil.
EROSION

The MOVEMENT of
rocks and
weathered materials
from one place and
dropped off
someplace else
(deposition).

The breakdown of
rocks by
chemicals such as
water or acid rain.

A lot of chemical
weathering is water
dissolving minerals
in rocks.


The physical
breakdown of rocks
into smaller pieces.
Organic,
temperature, frost,
gravity, and
“sandblasting.”



Roots of trees and
other plants are very
strong.
Roots can burrow
through rocks, pick
rocks up, and push
rocks downhill
Where do you
encounter root
wedging?
The activity of
burrowing animals like
worms, moles, and
bees (right) further
breaks down rocks.
 Worms even EAT soil
which is weathered
rock.

When rock is heated it
expands.
 When rock is cooled it
contracts.
 The constant
expansion and
contraction of rock
makes it brittle and
causes it to easily break
apart.





When water freezes it
expands.
Water from rain and the
groundwater gets into
small cracks.
When the water freezes,
it wedges the sides
opposite the crack apart.
This process continues
over and over, eventually
breaking a rock down.
Weathering by gravity
usually works in
conjunction with
something like frost
action or temperature
changes.
 When gravity pulls a
loosened piece of
broken rock, well that
makes the rock
smaller!

Otherwise known
as sandblasting.
 Happens when
wind or water
smash small rock
particles into
other rocks.


1. What are the two main types of
weathering?

2. What is the difference between
weathering and erosion?

3. Name 3 organisms that can weather rock.