Download rocks - Fort Thomas Independent Schools

ROCKS
Definition:

A rock is a mixture of
minerals
Igneous Rocks

Igneous rocks are formed as lava or magma
cools.
Igneous Facts:
 Basalt makes up most
of the ocean floor
and is the most
common igneous
rock.

If the magma cools
slowly beneath the
surface, INTRUSIVE
rocks result
 INtrusive rocks form
INside the Earth and
have large crystals
since there is time for
them to form.

If the lava cools
quickly on the surface
EXTRUSIVE rocks
result.
 EXtrusive rocks have
EXited the Earth and
have small crystals
since they formed so
fast.


Other igneous rocks….
Sedimentary Rock

Sedimentary Rock is made of sediment that has
been compacted and/or cemented together.
Sedimentary Facts:
 75% of the Earth’s surface rock is
sedimentary.
 Sedimentary rocks store ground water, oil,
and coal.


Clastic Sedimentary
rock is made of
fragments of other
rocks.

Organic sedimentary
rock has traces of
once living things in
the rock.

Chemical sedimentary
rocks are formed
when minerals
crystallize as a solution
dissolves

Sedimentary rock is held together by
COMPACTION and/or CEMENTATION:

During compaction,
rocks are squeezed
together because of a
lot of pressure from
above.

During cementation,
rocks are held
together by a mineral
‘glue’. Minerals fill in
the spaces between
the sediments and
bind them together
forming a solid rock.
Metamorphic Rock

Metamorphic rock is rock that has been changed
due to heat and/or pressure.

Foliated metamorphic
rock has bands of
colors through it

Non-foliated
metamorphic rock
does not have bands
of color.
Rock Cycle – any rock can become another rock