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Metamorphic Rocks
Sandstone: Quartzite, Metaquartzite
Shale: Phyllite
Slate
Schist
Gneiss
Limestone: Marble
Metamorphism of Sedimentary Rocks
Types of Metamorphism
Contact Metamorphism:The main metamorphic agent is heat.
Progression of metamorphism
Slate
Phyllite Schist
Start with a shale and then hitit with pressure and heat.
You end up with something that is really Gneiss!
Introduction to Metamorphic Rocks
Metamorphism is the solid-state transformation of pre-existing rock into texturally or mineralogically distinct new rock as the result of high temperature, high pressure, or both.
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”
Bands Layers
Banding vs. Layers
Schistose foliation- minerals have been squashed into flakes of mica.
Slaty foliation- Rock splits into flat, thin layers.
Take out your Handy Dandy Earth Science Reference Tables Page 7.
Slate
Phyllite
+
=
+
Phyllite
Schist
+
=
+
Schist
Gneiss
+
=
+
How does Metamorphism Relate to Plate Tectonics?
T and P increase at collisional (convergent) plate boundaries.
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