Transcript Metamorphic Rock Notes

Today’s Objective:
How are
Metamorphic Rocks
Classified?
Metamorphism – “to change form”
Formation of Metamorphic Rocks
- Most changes occur at high
temperatures and pressures a few
km below the Earth’s surface.
Gneiss Rock
What causes metamorphism?
Heat – Provides the energy needed to
drive chemical reactions.
- The heat comes from magma and
the change in temperature as you enter
into the earth
Pressure (Stress) – Causes a more
compact rock with greater density
ESRT pg 7 – Bottom
Contact Metamorphism –
Hot magma moves into rock
making contact with existing rock.
Regional Metamorphism –
Large amounts of pressure
results in large-scale deformation
and high-grade metamorphism.
(these rocks are very dense)
Types of Regional Metamorphism
•Pressure from
•Pressure from
being squished by plate movement
other sediments (mountain building)
Texture of Metamorphic Rocks
Foliated
Metamorphic Rocks - rock
has a layered or banded appearance.
Ex: Gneiss & Schist.
Banded
vs. Mineral Alignment
Notice the LIGHT dark
LIGHT dark layers
Crystals appear
squished together
Nonfoliated Metamorphic Rocks –
- Does not have a banded texture.
- Most only contain one mineral.
Marble - A Nonfoliated Metamorphic Rock
Parent Rock … What a rock begins as
For Foliated
Metamorphic
rocks as heat
and pressure are
added you start
with shale then
it becomes slate
then phyllite
then schist then
gneiss.
Parent Rock … What a rock begins as
For
Nonfoliated
Metamorphic
rocks as
heat and
pressure is
added, you
must look to
the
COMMENTS
column for
the parent
rock.
Using your knowledge of earth science, your
earth science reference tables and your class
notes to compare and contrast contact and
regional metamorphism in your notebook.
Regional
Metamorphism
Compare
Contrast
Contact
Metamorphism