Meta = change Morph = shape
Metamorphic Rock are rocks in which the structure, texture, or composition of the rock have changed.
The change is caused by heat, pressure, or a combination of both.
Deformation = a change in the shape of a rock caused by a force placed on it. The rock is squeezed and stretched causing it to fold and bend.

Two ways rock can undergo metamorphism:
Contact Metamorphism
Regional Metamorphism
Contact Metamorphism
Heated by nearby magma
More intense the closer the rock is to the magma
Near igneous intrusions
Some minerals can change into other minerals because of the heat

Regional Metamorphism
Caused by pressure built up deep in the ground
Caused when large pieces of the Earth’s crust collide with each other
Causes rock to become deformed and chemically changed
These types of metamorphic rocks are found far below most continental rock formations

Composition of Metamorphic Rock
Mineral composition of rocks can change as the rocks undergo metamorphism
The heat and pressure cause minerals to change into other minerals
INDEX MINERALS = Minerals that are used by geologists to estimate the temperature, depth within the Earth, and pressure at which a rock undergoes metamorphism

Textures of Metamorphic Rock
Two types: Foliated and Nonfoliated
Foliated Metamorphic Rock
Foliated = the texture of metamorphic rock in which the mineral grains are arranged in planes or bands
The effects of metamorphism depend on the amount of heat and pressure applied
More heat and pressure = cause minerals to separate into distinct bands

Sedimentary Shale
Slate

Phyllite
Schist

Gneiss

Nonfoliated Metamorphic Rock
Nonfoliated = The texture of metamorphic rock in which the minerals are not arranged in planes or bands
Usually made up on one or only a few minerals
Recrystalization = when minerals change in composition or crystals change in size due to the intense heat and pressure
Quartz sandstone . . . Quartzite

Limestone . . . . . . . . . . . Marble

Meta = change Morph = shape
Metamorphic Rock = rocks in which the structure , texture , or composition of the rock have changed.
The change is caused by heat, pressure, or a combination of both.
Deformation = a change of shape, the rock is squeezed . . . stretched . . . folded . . . bent
Two ways rock can undergo metamorphism:
Contact Metamorphism (heat)
Regional Metamorphism (pressure)

Composition of Metamorphic Rock
Mineral composition of rocks can change
Causes = heat and pressure
INDEX MINERALS = Minerals used to estimate the temperature, depth, and pressure
Textures of Metamorphic Rock
Foliated = mineral grains are arranged in planes or bands o More heat and pressure = cause minerals to separate into distinct bands
Nonfoliated = minerals are not arranged in planes or bands o One or only a few minerals o Recrystalization = minerals change in composition or crystals change in size