Transcript 4. Chemical Weathering

7th Grade
Unit 8:
Natural Events that Change
the Environment
Lesson 2:
Effects of Weathering and
Erosional Deposition
Vocabulary of Instruction:
Video:
Basics of
Geology
1. Abrasion
• Refers to the
grinding away of
rock by rock
particles carried by
water, ice, wind, or
gravity.
2. Bioerosion
• The process by
which animals,
through drilling,
grazing, and
burrowing, erode
hard substances
such as rocks
and coral reefs.
Crossbedded rippled burrowed sandstone.
3. Carbonation
• Is a form of
chemical
weathering
where carbonate
and bicarbonate
ions react with
minerals that
contain calcium,
magnesium,
potassium, and
sodium.
4. Chemical Weathering
• The process that
breaks down
rocks through
chemical
changes.
5. Climate
• General pattern of weather conditions
for a region over a long period time.
Moist Climate
Dry Climate
6. Deposition
• Where the
agents of
erosion (water,
wind, animals,
etc.). lay down
sediments.
7. Exfoliation
• The breaking off
of thin concentric
shells, sheets,
scales, plates, and
so on, from a rock
mass; measuring
less than a
centimeter to
several meters in
thickness, the
loosened rock is
spalled or
fragmented,
peeled, or stripped.
8. Gravitational Erosion
• Caused by gravity
and involves both
large scale mass
wasting and smaller
scale erosion.
Forms of
gravitational erosion
include avalanche,
landslide, debris
flow, mudflow, and
sinkhole formation.
9. Hydrolysis
• The chemical
reaction of a
compound
with water.
Hydrolysis is an
important
component of
soil formation,
and of chemical
weathering.
10. Ice Wedging
• Wedges of ice
in rocks widen
and deepen
cracks.
11. Mass Movement
• Any one of
several
processes
that causes a
down slope
movement of
sediment, soil,
and rock
material.
12. Mechanical Weathering
• The type of
weathering in
which rocks is
physically
broken into
smaller pieces.
13. Oxidation
• Is when a substance
reacts with oxygen to
form a type of
compound known as
an oxide that contains
at least one oxygen
atom.
14. Thermal Expansion
• Characteristic
property of
most solids and
liquids which
causes their
volume to
increase when
they are
heated.
15. Weathering
• Physical,
chemical, or
biological
breakdown
of rocks and
minerals into
smaller sized
particles.