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MELTING
MELTED ROCK
METAMORPHIC ROCK
THE ROCK CYCLE
HEAT AND
PRESSURE
IGNEOUS ROCK
SEDIMENTARY ROCK
WEATHERING, EROSION,
AND DEPOSITION
SEDIMENT
COMPACTION AND
CEMENTATION
The Rock Cycle
• The Earth is constantly changing. Even the very rocks around
you may have changed many times throughout their history!
• The Rock Cycle explains the evolution of these igneous,
sedimentary, and metamorphic rocks that make up the Earth’s
crust.
• Many processes, such as volcanic activity, movement of the
crust, and erosion and deposition of rocks on the surface, create
different environments where various types of minerals and
rocks form.
Back to the beginning
Let’s take a ride on the
Rock Cycle!
Melting…
MELTED ROCK
• Generally appears at
plate boundaries when crustal plates
are colliding or spreading
apart.
Lava
• Magma forms beneath
the surface.
• Lava is found on the
surface.
Go back to the Rock Cycle
Magma
Cool this melted rock!
Cooling…
IGNEOUS ROCKS
• Form as melted rock
cools.
• Can be extrusive or
intrusive.
• Examples include
granite, basalt, and
obsidian.
Go back to the Rock Cycle
Choose your own Adventure:
Add some heat and pressure!
Weather and erode this rock!
WEATHERING AND EROSION
• Did you know that the sand on the beach used to be part of a
rock?
• Once a rock is made, it doesn’t stay that way! If it is on the
surface, the rock is broken down into sediments by weathering
processes, then moved to a new location by erosional forces.
• Weathering is the process of decomposition or disintegration of
rocks in place.
• Erosion is the movement of weathered materials by water, wind,
ice, or gravity.
Go back to the Rock Cycle
Deposit sediment
SEDIMENTS
• Sediments are mineral or organic
particles that are deposited by
the action of wind, water, ice,
or gravity.
• Boulders, gravel, sand, and mud
are all types of sediments.
Go back to the Rock Cycle
Compact and cement these
sediments!
SEDIMENTARY ROCKS
•As the sediments settle, they compact.
•If the sediments are small enough, they
can form rocks.
•If the sediments are large, natural
cements fill in the empty spaces and
“glue” the sediments together.
Choose your own Adventure:
Examples of sedimentary rocks
include sandstone, shale, and
limestone.
Go back to the Rock Cycle.
Weather and erode this
rock!
Add heat and
pressure to this rock!
METAMORPHIC ROCKS
• These rocks have gone through a
lot!
• Metamorphic rocks form from preexisting rocks that have changed
due to high temperatures,
pressures, or chemical changes.
Examples of metamorphic rocks
include gneiss, slate, and marble.
Go back to the Rock Cycle
Choose your own Adventure:
Melt this rock!
Weather and erode this rock!
GLOSSARY
• Cement: A substance that hardens to act as an
adhesive; glue.
• Compact: become pressed together
• Erosion is the movement of weathered materials by
water, wind, ice, or gravity.
• Extrusive: an igneous rock formation environment
that occurs on the surface
• Intrusive: an igneous rock formation environment
that occurs beneath the surface
• Lava: molten rock on the Earth’s surface
• Magma: molten rock beneath the Earth’s surface
• Weathering is the process of decomposition or
disintegration of rocks in place.
Take me back to the Rock Cycle!
Granite
•Intrusive igneous rock.
•Cools slowly and has large crystals.
•Generally found on the continents.
Go back to Igneous Rocks
Basalt
• Extrusive igneous
rock
• Cools quickly and has
small crystals.
• Oceanic crust is
made up of basalt.
Go back to Igneous Rocks
Obsidian
• Often called “volcanic
glass”
• Extrusive igneous rock
that cools extremely
quickly.
• Does not have crystals.
Go back to Igneous Rocks
Sandstone
•A sedimentary rock consisting of
quartz sand cemented together by
other minerals.
•May be many colors, including
grey, yellow, red, and white.
•Is capable of holding large
quantities of water.
Go back to Sedimentary Rocks
Shale
• Formed from clay
and mud particles
that have been
pressed into thin
sheets.
• Extremely finegrained material
Go back to Sedimentary Rocks
Limestone
• Generally forms from calcite produced by marine organisms, and may
contain fossils.
• May also form from groundwater containing dissolved calcite.
• Will “fizz” when in contact with hydrochloric acid (HCl).
Go back to Sedimentary Rocks
Gneiss
• A coarse-grained rock with bands
of light colored minerals that
alternate with bands of dark-colored
minerals.
• Similar in composition to granite
(quartz, feldspar, mica)
Go back to Metamorphic Rocks
Slate
• Fine-grained rock composed
of metamorphosed clay or
volcanic ash.
• Generally forms when shale
undergoes metamorphism.
• Has distinctive layers.
Go back to Metamorphic Rocks
Marble
• Metamorphosed limestone
• Often used in sculpture and as a
building material
• Does not have layers or bands
Go back to Metamorphic Rocks