Rocks, rocks, and more rocks metamorphic

Rocks, Rocks, and More Rocks

Metamorphic

Classified according to the
arrangement of the grains that make
up the rock & the minerals in them


Metamorphic rocks are nicknamed
“Changing Rocks”.

Why?


How do Metamorphic rocks form?
From heat & pressure deep inside Earth


Metamorphic rocks can form from
Igneous, Sedimentary, or other
Metamorphic rocks as they are pushed
down toward the heat of the mantle.


2 Types of Metamorphic Rock
Foliated

“Banded”

Nonfoliated

“Nonbanded”


Foliated Metamorphic Rock
• Def: Grains arranged in layers
or bands that split into layers
• Examples:
Slate

Schist

Gneiss


Original Rock New Metamorphic Rock
Shale 

Slate

Shale (sedimentary) changes to Slate when heated & squeezed by pressure.


Original Rock  New Metamorphic Rock
Granite Gneiss

Granite (Igneous) changes to Gneiss when heated & squeezed by pressure.


Nonfoliated Metamorphic Rock

• Def: Mineral grains arranged
randomly, do not split into
layers
• Examples:
Marble Quartzite


Original Rock  New Metamorphic Rock
Sandstone Quartzite

When Sandstone (Sedimentary) is under extreme heat &
pressure, Quartzite will form.


Uses of Metamorphic Rocks
• Slate: Old fashioned chalkboards,
roofs, walkways, trim on
buildings

• Marbl *Sculptures (most famous –
e:
Lincoln Memorial in Washington
D.C.)
* Buildings


How are the 3 rock types related?


THE ROCK CYCLE!

• Use the online textbook – Active Art – to
complete the rock cycle diagram
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• Let’s learn the Rock Cycle Song…


The Rock Cycle
Song

To the tune of Row, Row, Row Your Boat

Sedimentary rock has been formed in layers
Often found near water sources
fossils and decayers
Then there’s Igneous rock, here since Earth was
born
Magma, lava cooled and hardened
that’s how it is formed
These two kinds of rocks can also be transformed
With pressure, heat, deep in Earth
Metamorphic they’ll become