Metamorphism &
Metamorphic Rocks
The Alps
Intro. Video for Flowchart
Meta what!!????
• The word metamorphism literally means
“changing of form” in Latin & Greek. In
geological terms, metamorphism refers to
changes to rocks that take place in the interior of
the Earth.
• These changes may be new textures, new
mineral combinations or both.
• These changes occur without the rock actually
melting.
• The new rock is called metamorphic rock.
How does metamorphic rock form?
• Metamorphic rock forms when a sedimentary rock, an
igneous rock, or even another metamorphic rock undergoes
changes in the Earth. These original rocks are called parent
rocks.
• Metamorphic rock forms the cores of the continents and
mountain chains.
What factors control the characteristics of
metamorphic rocks?
The characteristics of metamorphic rocks
depends on the following:
• Makeup of the parent rock
• Temperature
• Pressure
• Fluids (usually hot water)
• Time
Temperature & Pressure
How do we classify
metamorphic rocks?
• Metamorphic rocks are classified
according to texture and the type of parent
rock.
• There are two main types of metamorphic
rocks: foliated and non-foliated.
Foliated Metamorphic Rocks
• Metamorphic rocks with more than one mineral are
usually foliated. This means that the different minerals
have formed bands or layers. Foliated rock can usually
break along its layers.
Maryland, USA
Examples of Foliated
Metamorphic Rocks
Slate (formed from shale)
Schist (formed from slate)
Nonfoliated Metamorphic Rock
• Metamorphic rock with only one mineral is
nonfoliated. This type of rock does not contain
layers.
Pink marble with no layers!
Examples of Nonfoliated
Metamorphic Rock
Scotland
Marble (formed from limestone)
More Examples of Nonfoliated
Metamorphic Rock
Dolomite marble (formed
from dolomite)
Quartzite (formed from
sandstone)
Hornfels (formed from
basalt or shale)