Download original rock

Metamorphic Rocks
Metamorphic rocks – Rocks formed under intense
() and/or ().
Metamorphism causes (), changes in the rock’s () crystals without
actually ().
Made of small
grains of sand
Sandstone
As the rock is exposed to ()
and/or () the individual mineral
grains recrystallize.
Grains are
much larger
Quartzite
There are 2 types of
metamorphism that occur.
1.
Contact metamorphism – Heat from () or () alters
older rock it ().
The changes only occur in the rock
that are in close () with the ()
(liquid) rock.
() metamorphism
Lava
Contact
Metamorphism
Contact
Metamorphism
Contact metamorphism
Extrusive Igneous Rock
Metamorphic
Rock
Metamorphic Rock
Contact Metamorphism – () the ()
rocks
Parent Rock
What is parent rock you ask…
Side Note
All metamorphic rocks come
from () in a () rock.
The parent rock is the original rock the
metamorphic rock came from.
Lets take a look.
Parent Rock
Contact metamorphism
Parent rock
Metamorphic rock
Parent Rock
Contact metamorphism
Parent rock
Metamorphic rock
Parent Rock
It doesn’t say, but what sedimentary
rock do you think is the parent rock?
conglomerate
Parent rock
Metaconglomerate
Metamorphic rock
The
nd
2
type of metamorphism
that occurs.
2.
() metamorphism – heat and pressure
combine to alter () over a large area.
These rocks get changed when ()
plates collide. The () the rock is to
the plate boundaries the more the
rock gets changed.
Differential stress
Regional metamorphism can
create mountains!!!
Folded rock caused by plate tectonics
Regional Metamorphism (large area)
Folded rock caused by plate tectonics
Regional Metamorphism (large area)
What is the parent rock???
Foliation
Rock type and depth of burial
() regional metamorphism (high
heat and pressure) () the
minerals in a rock. This flattens
and () the minerals.
Foliated – flattened and aligned minerals. ()
rocks split easily along the
flattened, aligned mineral layers.
Lets see what foliation looks like…
The minerals
normally line up
perpendicular to
the direction of
the pressure.
Pressure
Pressure
When the minerals are () into light
and dark mineral layers it is called ()
Nice!!!
oops…
Gneiss!!!
Banding – (special foliation) of light and dark mineral
layers.
One more thing… Since metamorphic
rocks are formed under such () what
do think happens to their ()?
() metamorphosed rock will usually be () then the parent
rock.
Summing it all up
() metamorphism – just () that
changes rock
Regional ()– heat and ()
change rock
Reference tables page 7
Metamorphic Rock Identification
Lets check out the properties of
metamorphic rocks.
What it looks like
How big the mineral grains are
What minerals are in the rock
Is it formed by regional or
contact metamorphism
Important information
Umm, rock names
How the rock may be
shown on a map
Lets try to figure out a mystery
metamorphic rock.
Observed properties:
1. The texture is foliated,
minerals are aligned but
not banded.
2. The grains are fine to
medium sized.
3. Contains, mica, quartz,
feldspar, amphibole,
garnet and pyroxene.
1. The minerals are aligned but not
banded.
2. The grains are fine to medium
sized.
3. Contains, mica, quartz, feldspar,
amphibole, garnet and pyroxene.
Through which rock do all the
properties match?
Our mystery rock is…
Yup, it is Schist.
We can figure out
information about any
metamorphic rock
with the E.S.R.T.