Metamorphic Rocks Flashcards
Metamorphic rock
A rock formed by large amounts of pressure and heat
What happens to metamorphic rocks as they are exposed to heat/pressure
They form different rocks aswell as producing new minerals
Protolith
The unmetamorphosed rock
How do metamorphic rocks affects minerals
Metamorphic rocks change shape and size without changing mineral identity aswell as changing crystal structure without changing mineral composition
Foliation
The arrangement of mineral grains which makes a rock a striped appearance
Why does foliation occur
Foliation occurs because pressure from the earth squeezes the minerals in a rock to become aligned
How does foliation occur
In the earth, the horizontal forces usually exceed the vertical forces which results in the minerals of a rock to have a preferred orientation making them look aligned
Compression
When an object shrinks but holds its shape
Stress
The force acting on an object in only one direction
Non-foliated rocks
Rocks which form in areas where there is low pressure and high temperature. This results in the rock only containing one mineral
Contact metamorphism
When non-foliated metamorphic rocks are created as a result of being heated by magma
Burial metamorphism
When sedimentary rocks are buried in continental rifts which produces foliated rocks
Regional metamorphism
Foliations in metamorphic rocks as a result of tectonic forces
Subduction Zone Metamorphism
When subduction of the lithosphere produces metamorphic rocks
Mineral assemblage
The different types of minerals in a rock
