Warm-Up
• What are the five characteristics that make a
mineral a mineral?
• List 6 ways you can identify a mineral by
physical properties?
• How do igneous rocks form? What are the
two classifications of igneous rocks?
• How can you differentiate between the two
igneous rocks? Give three specific examples
The Rock Cycle Movie
• https://www.youtube.com/watch?v=CvDw07i
YaJQ
• Write 5 Facts
• Complete video assessment at the end
What are the differences? Similarities?
Igneous
Rock
Metamorphic Rock
Earth’s 5 Structures
lithosphere
asthenosphere
mantle
outer core
inner
core
This slide show is intended to help you
understand important types of rocks.
The diagram in the next slide represents the ROCK CYCLE—a
scheme that represents the processes of continuous changes
that connect the three major groups of rocks:
SEDIMENTARY
IGNEOUS
METAMORPHIC
It also shows two other important parts of the “Rock Cycle” –
SEDIMENTS and molten LAVA and MAGMA
Here is another version of the Rock Cycle
Warm-Up
• Define the 3 rock types: igneous,
sedimentary, metamorphic
Igneous Rocks Are Separated into Two
Main Categories
EXTRUSIVE
INTRUSIVE
Igneous Rocks
• Igneous rocks are rocks that are formed from
the crystallization of magma.
Heat and
melting
Magma
Cooling and
crystallization
Igneous Rocks
Sedimentary Rocks
Sedimentary rocks may be made of rock fragments—sediments—
or by chemical reactions. The classification of sediments is
shown below.
Metamorphic Rocks
• Are rocks formed from an increase in pressure
and temperature deep within the lithosphere.
Clastic rocks–made of cemented sediments—are
classified by their grain sizes.
Non-clastic rocks form by chemical precipitation (settling
out from a solution.) Limestone is made from calcite,
chert from quartz, and halite is rock salt.
Biologic sedimentary rocks come from the
remains of organic matter.
• The most important of
these is coal. Anthracite
coal results from the
greatest pressure and
releases the most energy
when burned. Other
varieties are bituminous
and lignite. “Petrified”
(permineralized) wood is
another organic rock.
More about sedimentary rocks
• Shale is the most
common sedimentary
rock
• Sedimentary rocks
cover about threequarters of the land
surface
Sedimentary Rocks
• Rocks formed from lithification.
lithification
• transformation of sediments into rock
through compaction and cementation
Compaction
 the process in which pressure squeezed
air and water out and pushes fragments
together
 pressure comes from rock layers above
Cementation
 the process in which water and
minerals combine to from cement
that holds sediment together.
Three Types of Sedimentary Rocks
• Clastic Sedimentary Rocks
• Evaporites Sedimentary Rocks
• Organic Sedimentary Rocks
organic - once living
Chemical Sedimentary Rocks
• Formed from minerals that were
once dissolved in water
Evaporites
• Formed when a
change in
temperature
caused water to be
evaporated
• Examples: Gypsum
and Halite
GYPSUM
HALITE
Organic Sedimentary Rock
• formed from the remains of living
things
FOSSILIFOROUS
LIMESTONE
Metamorphic Rocks
• Are rocks formed from an increase in pressure
and temperature deep within the lithosphere.
How are metamorphic
rocks classified?
Metamorphic rocks are
classified by how they are
formed.
Three Types of
Metamorphic Rocks
• Contact Metamorphism
– occurs when molten rocks, such as those in an
igneous intrusion, come in contact with solid rock
Regional Metamorphism
• are produced when high temperature and
pressure affect large regions of Earth’s crust.
• the grade of regional metamorphism reflects
the intensity of temperature and pressure
• classified as low grade, intermediate grade,
and high grade.
Metamorphic Rocks Are Classified By
Their Texture
MARBLE IS
NONFOLIATED
GNIESS IS
FOLIATED
Nonfoliated
• composed mainly of minerals that form with blocky
crystal shapes.
– Quartzite and marble are two common examples of
nonfoliated rocks.
Foliated
• metamorphic rocks are characterized by bands of
minerals
• high pressure during metamorphism causes minerals
with flat or needlelike crystals to form with their
long axes perpendicular to the pressure
Chemical Change
• When hot fluids, water or magma, migrate in
and out of the rock during metamorphism the
original composition of the rock can change.
• Minerals melt into a liquid state then
recombine with other elements to create
new minerals.
Mineral Changes
• During metamorphism, the minerals in a rock
change into new minerals that are stable
under the new temperature and pressure
conditions.
Locations, types, and
ages of the bedrocks
are represented in a
geologic map
http://www.state.nj.us/dep/njgs/