Transcript Metamorphic Rocks

Metamorphic Rocks

Rocks
 1. Rocks can go through changes where
they become a brand new rock. This
process is called
__metamorphism__________.
 2. This word is Greek. Meta means
____changed_______ and morphos
means __shape________.
Rocks
 3. Metamorphic rocks occur when the
__structure_____, ___texture____, or
__composition____ of the rock have changed.
 4. All of these types of rock
(__igneous________, _____sedimentary_____
and _____metamorphic_____) can be
changed by __heat____, ___pressure___, or a
combination of both.
Origins of Metamorphic Rock
 5. Texture or mineral composition of a rock can change if
the __temperature____ or __pressure____ of the new
environment is different from the one that the rock was
originally formed in.
 6. The temperature that most metamorphism will occur is
between __50__ oC to __1000__ oC. However some rocks
will go through metamorphosis above 1000oC.
 7. The __depth__ and __pressure___ that metamorphic
rocks form is what allows the rock to heat to this
temperature and stay solid.
Origins of Metamorphic Rock
 8. The depth that most rocks go through
metamorphic changes is at depths greater than
_2_ km (kilometers) which is about 1.25 miles.
 9. Large movements within the crust of the
earth adds more _pressure__ on the rock
during metamorphism. This can cause
__mineral____ __grains___ in rock to align
(line up) in certain directions.
Composition of Metamorphic Rock
 10. Metamorphism happens when
__temperature____ and ___pressure____
inside Earth’s crust change.
 11. Original ___minerals___ change into new
___minerals____. For example calcite, quartz,
and hematite will crystallize to form the
metamorphic mineral __garnet__.
Textures of Metamorphic Rock
 12. Scientists classify igneous,
sedimentary, and metamorphic rocks by
their __texture__.
 13. Metamorphic rocks have two textures
- __foliated____ or ___nonfoliated____.
Foliated Metamorphic Rock
 14. The texture of a metamorphic rock
that has mineral grains arranged in
__planes___ or __bands___ is called
__foliated___.
 15. This metamorphic rock usually
contains __aligned___ (lined up) grains of
__flat_ minerals.
Foliated Metamorphic Rock
 16. A metamorphic rock can continue to change
into another __metamorphic____ rock if it
exposed to more __heat___ and ___pressure____.
For example: sedimentary shale becomes
__slate___ (metamorphic), which become
__phyllite___ with more heat and pressure. Then
with more heat and pressure it can become
__schist__, only to have more heat and pressure
make it become _gneiss_.
Nonfoliated Metamorphic Rock
 17. The texture of a metamorphic rock that has
mineral grains that are not arranged in __planes___ or
___bands__ is called ___nonfoliated___. The minerals
are not __aligned__ (not lined up).
 18. These rocks are commonly made of _1__ or only a
few minerals.
 19. During metamorphism, the crystals of the minerals
may change in __size___ or __composition___ called
__recrystallization____.
Nonfoliated Metamorphic Rock
 20. Examples of this are: quartz sandstone
(sedimentary rock) is exposed to __heat__ and
___pressure___, and the minerals recrystallize
to form __quartzite__; also limestone is
exposed to __heat___ and __pressure___, and
the minerals recrystallize and become
___marble____.
Metamorphic Rock Structures
 21. When metamorphic rocks change shape
because of force placed on them, they can be
__squeezed___ or _stretched____. This is
called __deformation___. Some deformations
are called __folds__ or __bends__.
Examples
Quartzite is a coarse-grained
metamorphic rock derived from sandstone.
Marble is a metamorphic rock that comes
from metamorphosed limestone or dolomite.
Examples
Slate is a fined grained metamorphic rock.
Phyllite is a fined grained metamorphic rock.
Examples
Schist is a course grained metamorphic rock.
Gneiss is a medium to course grained
metamorphic rock.