Rocks are categorized into three types—igneous, sedimentary, and metamorphic—based on their formation processes and characteristics. The rock cycle illustrates how rocks transform from one type to another over time through processes like melting, cooling, and chemical changes, driven by plate tectonics. Key interactions include weathering, erosion, lithification, and the effects of heat and pressure on rocks.

1. Rocks and the Rock Cycle

2. Three Types of Rocks
• Rocks are
classified by how
they form
– Igneous
– Sedimentary
– Metamorphic
– Rocks can change
from one type to
another over time
Schist

3. Rock Classification
• Rocks are
classified by:
– How they form
– Texture
– Grain size
– Mineral
composition
Conglomerate Sedimentary Rock

4. Igneous Rocks
• Igneous rock:
forms when molten
rock (magma) cools
and hardens
• Classified by:
– Where they form
– Crystal (grain) size
Basalt

5. Intrusive Igneous Rock
• Intrusive igneous:
cooling takes place
slowly beneath
Earth’s surface
granite

6. Extrusive Igneous Rock
• Extrusive igneous:
cooling takes place
rapidly on Earth’s
surface
Pumice

7. Sedimentary Rock
• Sedimentary rock:
forms from the
compaction and/or
cementation of
sediments
• This process is
called lithification
• Sediments are:
– Rock pieces
– Mineral grains
– Shell fragments
Limestone

8. How do sediments form?
• Sediments form
through the
processes of
weathering and
erosion of rocks
exposed at Earth’s
surface
weathering
erosion

9. Sedimentary Rock con’t….
• Sedimentary rock
can also form from
the chemical
depositing of
materials that were
once dissolved in
water
• When water
evaporates, minerals
are left behind and
form rock
gypsum

10. Metamorphic Rock
• Metamorphic rock:
forms when any
rock type is
changed into a
different kind of
rock
• Changes due to
great heat and/or
pressure Gneiss

11. How does rock change?
• Rocks are heated,
squeezed, folded,
or chemically
changed by contact
with hot fluids
marble

12. The Rock Cycle

13. The Earth Recycles Rock
• The rock cycle is an
ongoing series of
processes inside Earth
and on the surface
• Slowly changes rocks
from one kind to another
• Any type of rock can
change into another type

14. How does this relate to
plate tectonics?
• Plate movement drives
the rock cycle
– Subduction (1 plate
pushed under another
plate)
• Re-melts rock into magma
– Mountain building
• Folding, faulting, uplift
• Exposes rock at the
surface to be weathered
and eroded

20. a. Cementation and compaction (lithification)
b. Heat and pressure
c. Weathering, transportation(erosion), and deposition
d. Cooling and solidification
e. Melting

21. Rocks/Rock Cycle Foldable
• Your foldable should include
the following:
1.Name of each rock type
2.How each rock type formed
3.A brief description of rock
type
4.At least 2 examples of each
rock type
5.Illustrate 1 example for each
rock type

22. Copy Me

23. Do Now – Tuesday March 11
In Textbook:
• Complete
• pg. 107 #1-8

24. Do Now – Thursday March 4
Rock Texture Composition Comments
Conglomer
ate
Coarse,
2mm
Rounded
pebbles
Rounded pebbles,
sand and clay can
easily be seen
Sandstone Medium,
.0625 – 2 mm
Quartz, other
minerals and
rock fragments
Sand grains can be
seen; rough surfaces
Shale Microscopic,
.004 - .06 mm
Clays, micas Has muddy
appearance
Limestone Coarse to fine Calcite, shells May contain fossils,
seashells; fizzes
when in hydrochloric
acid
Chert Fine Quartz Is light-colored; also
called flint; once used
for arrowheads
Rock salt Coarse to fine Halite Has salty taste;
table salt
Limestone is composed of the mineral
A. quartz
B. calcite
C. halite
D. gypsum
Based on the information given about each of these
rocks, into which rock type would all these examples
be classified?
A. Igneous
B. Metamorphic
C. Sedimentary
D. Mineral

25. Gypsum
Moh's
Hardness Scale
Approximate Hardness of
Common Objects
Talc
Gypsum
1
2 Fingernail (2.5)
Calcite 3 Copper penny (3.5)
Fluorite 4 Iron nail (4.5)
Apatite 5 Glass (5.5)
Feldspar 6 Steel file (6.5)
Quartz
Topaz
7 Streak plate (7.0)
Topaz 8
Corundum 9
Diamond 10
Which statement is best
supported by the data
shown?
A. An iron nail contains
fluorite.
B. A streak plate is
composed quartz.
C. Topaz is harder than a
steel file.
D. Apatite is softer than a
copper penny.

26. Based on the
processes shown in
the diagram, which
type of rock is formed
at #1?
A. Sedimentary
B. Igneous
C. Metamorphic
D. Clastic
Because heat and
pressure are needed
to form #3, it must be
what type of rock?
A. Sedimentary
B. Igneous
C. Metamorphic
D. Clastic