Download Metamorphic Rocks - Connolly, Harold

Metamorphic Rocks
• What is a metamorphic rock?
• Rocks, either igneous, sedimentary, and/or
metamorphic, that have been changed in size,
shape, texture, and even mineralogy by the
application of heat, pressure, and chemically
active fluids.
Metamorphic Rocks
Metamorphic Rocks
Metamorphic Rocks
• The precursor to a metamorphic rock
(what the rock type was before
metamorphism) is known as the
protolith.
Metamorphic Rocks
•
How are metamorphic classified?
1. Foliated - Parallel surfaces or apparent
layers of minerals.
2. Non-foliated - The rock lacks any
apparent layering.
Metamorphic Rocks
Environments of Metamorphism
Contact metamorphism - this is usually
localized and occurs when magma comes
into contact with surround rock. The
rock surrounding the magma gets heated
and changed.
Environments of Metamorphism
Environments of Metamorphism
Regional Metamorphism - occurs over a
large area on the continents and is
associated with mountain building
epochs.
Environments of Metamorphism
Environments of Metamorphism
Environments of Metamorphism
•
Dynamic Metamorphism - occurs in
fault zones and is the result of tectonic
movement.
Environments of Metamorphism
• Rifting Metamorphism - metamorphism
associated with tectonic rifting events.
• Mid-Ocean Ridges - metamorphism through
heat and hot water at mid-ocean ridges.
• Subduction Zone - The creation of blueschists,
which are rare rocks.
Environments of Metamorphism
Environments of Metamorphism