19
The Rock Cycle: One of Earth’s Subsystems
Magma
Igneous
Rock
Sediment
Sedimentary
Rock
Metamorphic
Rock
Lava
ROCK CYCLE
Heat
(
h
e
a
t
,
i
n
t
e
n s e p r e s s u r e )
L i t h i f i c a
t i o n
t r a n s p o r t , d e p o s it io n
M e lt in g
M
e
t
a
m
o r p h i s m
( c o m p a c t i o n , c e
m
e n t a t i o n )
W e a t h e r in g ,
C o o l i n g , c ry st allization
Magma forms when
rock melts deep
beneath Earth’s
surface.
When magma or lava
cools and solidifies,
igneous rock forms.
Weathering breaks
down rock that is
transported and
deposited as
sediment.
Sediment is
compacted and cemented
to form sedimentary rock.
When sedimentary
rock is buried deep
in the crust, heat and
pressure (stress) cause it
to become metamorphic rock.
U p li f t , w e a th e ri n g , tr an sp or tat ion, and depositio n
U p li f t , w e a t h e r i n g
, t r a n s p o r t a t io n , a n d d e p o si tio n
Melting
M e ta m o r p h is m
FIGURE 1.22 Viewed over long spans, rocks are
constantly forming, changing, and reforming. The
rock cycle helps us understand the origin of the
three basic rock groups. Arrows represent
processes that link each group to the others.