DATE
CLASS
STUDY
GUIDE
Use words in the box to fitl in'the blanks.
METAMORPHIC
ROCKS
18:1 Originof Metamorphic
Rocks
15
low
800
core
lower
burial
three
degree
fluids
weight
cracks
intense
solutions
reacting
contact
regional
chemistry
metamorphic
enlargement
rearrangement
Rockschanged-bytemperatureand pressureare called meh,vro,"PLLrocks. During
metamorphism,
'
temperatures are usually
lol.ue*than required for melting. At
a depth of 12 to
lf
, km, temperaturesrange from 150 to
occurin threg
$<cf)
ways: R*,rn*rgr-*rtf
and./or changes in the
rrzelari,i-
minerargrains,
ofthe rock.
-pressure and iow-temperature changes.
Mountain building processesoften coincide with
corg-
the mountain
of crystals,
metamoryhism ocfllrs due to the
low
of overlying rocks causing
J
"C. Metalorphic cha.nges
can
metamorphism. Rocks sulrounding
are subjectedto
rn'Fevrse--
temperaturesan6 pressure.The
metamorphism
decreases with distance from the mountain core. when magma
+of
<c.q&b
intrudes into
changed by heat,
4l"l/s
o/-rri,lr,f
in overlyingrock,
metamorphism occurs. The rock is
, and gases from magma. New minerals are formed as
move through the sunounding rocks
ne.rel*Jn$
with the elements present.
18:2 Metamorphic
RockGomposition
clay
type
slate
stable
parent
gneiss
New mineralsthat
"""
s+aL[e-
during metamorphism.The
at higher "lpnf*ile;u&and
of rock formeddependson the
rock
rck and the level
ievel of temperaturesand
,, 0rr.re-vr*TI
is subjected. The sedimentar5r rock shale, composed fi
tl
slq'fe-
.
-
; a slate will becom
" "
pressuresare oft,enformed
fL:u,
it-rle-
At high temperatures and pressure, granite will change to
".rT,,ilio^
of the
Pfe31.,.fe
to which the parent rock
Chv
minerals, will change to
with increasedpressureand temperature.
NAME
DATE
CLASS
18:3 Classification
of Metamonchic
Rocks
one
mica
slates
marble
-
layers
phyllite
internal
compact
Metomorphic rocks are classified tv
*"ltal*L
5l"les
texbure
schists
graphite
foliated
{exLne
gnersses
quartzite
nonfoliated
anthracite
Rocks that are banded are called
At about 150"C, minerals begin to line up in bands, o,
show no visible internal changes but are
rock.
shinesbecause
and increased foliation occur
rccur in
sclti+
nicA
^or.
**f*
la)rre.rS
thari the parent
flakes are present. Jhkfmi
change
, the most co'.mon metamorphicrock. 6neE*-S
are due to high temperatures and prgssures. MaFsive metamorphic
rocks showing no banding are called
no"t&ltc{*L . Rocks of this type usually contain only _--. €r€--__
-'lc''vlrolla\.'t'€P\
,t..nJ/*
limestone,,
temperatures into
temperature and pressure.
; sandstoneformsthe rocf /q<zr^.Lr'*e-
minetal. Metayr.mrphosed
. Soft coal."o
coal, which then becomes nr.a.lri'rle*
vl
rrr*at low
"t
with increased