• Rock: the material
that makes up the
solid parts of Earth
– a collection of one or
more minerals
– or of solid organic
matter
• Geologists: scientists
that study the forces
and processes that
form and change the
rocks of Earth’s crust
Target #20- I can
describe rocks
Target #21- I can identify
what a geologist does
Target #22- I can differentiate
between rocks and minerals
• Rocks vs. Minerals
– Rocks are a composed of one or more minerals.
• A rock can be made up of only one mineral or, a
number of different minerals.
– Minerals are composed of one or more
elements.
All rocks are made of 2 or more minerals, but
minerals are not made of rocks.
• Igneous rocks
– “igneous” comes from the
Latin term “from fire”
– Formed from volcanic
activity when magma, or
molten rock, cools and
hardens
• Two types
– Intrusive- formed inside
the Earth
– Extrusive- formed outside
the Earth
Target #23- I
can describe
igneous rocks
Target #24- I
can identify the
types of
igneous rocks
• Sedimentary Rocks
Target #25- I
can describe
sedimentary
rock
– Sediment: small mineral
fragments
• forms when rocks are broken
down from wind or water
erosion
– Sediment is carried away
and deposited by water, ice,
and wind that are
compressed or cemented
together and harden
forming sedimentary rocks
Target #26- I can describe
metamorphic rocks
• Metamorphic Rocks
– Metamorphic means “changed form”
– Form when existing rock is altered through
tremendous pressure, extreme heat, or chemical
processes
• Rock Cycle: the
series of processes
in which rock forms,
changes from one
type to another, is
destroyed, and forms
again by geological
processes
Target #27- I can
explain the rock
cycle
• Igneous rock can be
broken down into sediment
• Sediment is then
compacted to become
sedimentary rock
• If sedimentary rock is
subjected to changes in
temperature and pressure,
the rocks may become
metamorphic rocks
• Under certain
temperature and
pressure conditions,
the metamorphic rock
could melt into
magma, which will resolidify into igneous
rock
• Any of the three
major types of rock
can be changed into
another of the three
• Even though rocks
have passed through
the rock cycle many
times, a particular
body of rock may not
pass through each
step of the cycle