1. Changing form due to heat and/or pressure
Metamorphic Rocks
Changing form due to heat and/or pressure

2. The Rock Cycle This is the changing of rocks from one type to another.
Each rock type may turn into any other rock type

4. Metamorphic rocks form right where the action is:
in the center of mountain belts during continental collisions (regional meta.)
along subduction zones as the slabs grind ever deeper below the surface (regional meta.)
right next to magma chambers as they slowly radiate heat (contact meta.)

5. Metamorphic rocks
are rocks that have undergone a solid- state (NO melting) recrystallization in response to changes in temperature and/or pressure
During metamorphosis, the original mineral grains in a rock may
grow larger,
stay the same, or
break down and form new minerals

6. The changes that occur depend on: 1. the starting minerals 2
The changes that occur depend on: 1. the starting minerals 2. the pressure 3. temperature 4. the fluid conditions associated with the kind of metamorphism.

7. Changes
The rock from which a metamorphic rock forms is called the “protolith” or parent rock
Ex. Shale  Slate, Limestone  Marble

9. Classification
Classification based on texture, grain size, and composition
The major division of metamorphic rock texture is between foliated and non-foliated.
Foliated means minerals arranged in horizontal layers due to pressure

11. Slate
very fine-grained rocks that split along flat surfaces from the microscopic clay and mica minerals

12. Phyllite/Schist
are the next higher grade of metamorphic rocks from slates.
Schists have mineral crystals large enough to be identified and usually have wavy foliation textures
Often contain garnet, staurolite, kyanite, and sillimanite

13. Gneiss Gneiss is banded
Banding- minerals aligning due to pressure, forming straight tor wavy lines in a rock

14. Non-Foliated
Non-foliated mostly formed by heat, minerals randomly oriented
No layers because low pressure
Minerals may appear crystalline

15. Marble
Marbles are limestones that have been metamorphosed (calcite is recrystallized)
May be banded

16. Quartzite Form when quartz sandstones are metamorphosed
May preserve sedimentary structures

17. Metaconglomerate Metamorphosed conglomerate or breccia
Pebbles looked stretched