Sire Kassama
2014
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Metamorphic Rocks: Rocks created through
intense heat or pressure
Are good examples of metamorphic rock:
gneiss, schist, slate, marble
Alps and Himalayas are primarily composed of
metamorphic rocks
Foliated metamorphic rocks are rocks that have
bands of minerals in it
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Describe the only location that provides the
intense and extreme heat and pressure required to form metamorphic rocks.
Deep within the earth; lithosphere; or
subduction zone
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Local or Contact Metamorphism: rocks touched
by red hot magma in crust; whenever magma
rises to crust
Regional Metamorphism: deep in crust from
enormous pressure over a large area; two
tectonic plates move toward each other;
Lewissian gneiss is a good example
CONTACT
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REGIONAL
occurs adjacent to
igneous intrusions
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Both
Contact may result from tectonic forces
resulting in compressional stresses
usually results in foliated metamorphic rocks
mineral crystals are rearranged
results in folds or curves
large crystals are formed
minerals crystallize
Rock
Color
Foliated
Grain Size
Shale
Dark gray
Yes
Fine
Schist
Mixture
No
Medium
Gneiss
Pink or gray
Yes
Coarse
Marble
Light
No
Coarse
Quartzite
Light
No
Coarse
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ROCK NAME
TYPE ( Igneous, Sedimentary, metamorphic)
FORMATION
Igneous (Extrusive, Intrusive) (volcanic, plutonic) (felsic or mafic)
Sedimentary ( Clastic, chemical, biochemical, organic)
Metamorphic (Regional, Contact Metamorphism) (low grade-high grade)
ENVIRONMENT
TEXTURE
Igneous (phaneritic, aphanitic, porphyritic)
Sedimentary (grain size)
Metamorphic Foliated or non-foliated
HARDNESS RANGE
MINERALS
PHYSICAL DESCRIPTION
(Color)
USES
OTHER PROPERTIES
Base your answers to this question on the
pictures of four rocks shown below. Magnified
views of the rocks are shown in the circles.
What do all four rock samples have in
common?
1.They show cleavage.
2. They contain minerals.
3. They are organically formed.
4. They formed on Earth’s surface.
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Base your answers to this question on the pictures
of four rocks shown below. Magnified views of the
rocks are shown in the circles. Which rock is
metamorphic and shows evidence of foliation?
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Which sample best shows the physical
properties normally associated with regional
metamorphism?
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Reacts with HCl and therefore contains the
mineral calcite
Formed by metamorphism of limestone
Minerals: Calcite
Has no foliation
Red, white, yellow, green
Found in US, Italy, Canada, Spain, Greece
Used in sculptures, Lincoln memorial
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Fine grained rock formed when shale,
mudstone, clay, or volcanic ash is put under
high pressure
Splits into thin sheets easily
Almost completely waterproof
Used for roof and floor tile, monuments, and
name plates
Minerals: mica, feldspar, and quartz
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Medium grained
Made from shale, clay, slate, and many other
rocks
Put under very high temperatures and
pressures
Minerals: feldspar, mica, quartz
Good for building materials
Also crushed into gravel to use for pavements
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Formed at very high temperatures and
pressure from different igneous and
sedimentary rocks
Coarse grained and has bands of minerals that
are often bent and folded
Formerly granite before exposed to immense
pressure
Used to replace granite
Common metamorphic rock
Found in Sweden
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Formed when sandstone is heated
Formed when tectonic plates grind together
Some of the oldestest rocks made of quartzite
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The following questions and answers are from
the New York State Regents Website:
http://www.regentsprep.org/Regents/core/q
uestions/topics.cfm?Course=ESCI
Geology.com
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Contact metamorphism: alteration of rock by heat
adjacent to hot lava; important setting fir metallic
ores such as gold, silver, copper, zinc, lead, etc
Regional metamorphism: alteration of rock over
large area by het and pressure due to deep burial
or tectonic process
Metamorphic Rocks are either foliated or
nonfoliated
Foliated: laminated structure in rock resulting
from parallel alignment of sheet like minerals (
slate, phyllite, schist, gneiss)
Nonfoliated: no preferred orientation (marble ,
quartzite)