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Rocks
How They Are Made
By
Mr. Haynes
Volcanoes
• Volcanoes are made
of many things that
make rocks.
• The three parts of a
volcano are magma,
lava, and the crust.
Magma is molten rock below ground.
Magma is extremely
hot! Great pressure
from under ground
pushes the magma to
a crack in the crust of
the earth. Then a
volcano forms.
The volcano erupts.
• Lava is molten rock
above ground.
• Lava shoots out of the
volcano and runs
down the crust.
• The crust is the side
of the volcano.
Lava is extremely hot!
When the lava
cools, it turns into
different forms of
rocks.
There are three
forms of rock. They
are igneous,
sedimentary, and
metamorphic.
Igneous rock forms when magma cools above or
below ground.
• Granite is an igneous
rock with shiny
speckles. It is a very
heavy rock.
Sedimentary rock is formed when tiny bits of rock
are pressed together underwater.
• Most fossils are found in
sedimentary rocks.
• Sedimentary rock is
made over millions of
years at the bottom of
lakes and rivers.
• Sandstone is a
sedimentary rock.
Metamorphic rocks are rocks that have been changed by
heat, pressure, and millions of years.
• Metamorphic rocks were
once sedimentary or
igneous rocks.
• Quartz is a metamorphic
rock.
3 Types of Rocks
• Igneous- formed when magma cools
• Sedimentary- formed when tiny bits of rock
are pressed together
• Metamorphic- formed when rocks are
changed by heat, pressure, and time
CSUN