Metamorphic Rocks
Metamorphic rocks have
been changed from a
pre-existing rock.
Caused by extreme heat
and/or pressure.
Regional Metamorphism
Caused by extreme
pressure and heat.
Happens over wide
“regions”.
Contact Metamorphism
Caused by contact
with extreme heat.
Meta. rocks will often
have foliation or a
distorted structure.
Distorted Structure
Foliation is a “grain” to the
rock.
Types of Foliation:
Gneissic Foliation- minerals
are squished into bands.
“Zebra Stripes”
Banding vs. Layers
Bands
Layers
Schistose foliationminerals have been squashed
into flakes of mica.
Slaty foliationRock splits into flat, thin
layers.
Take out your Handy Dandy Earth
Science Reference Tables Page 7.
Slate
+
+
=
Phyllite
Phyllite
+
+
=
Schist
Schist +
+
=
Gneiss