| Shale-
Consists of mostly clay grains and silt or sand with water and disolved
chemicals. |
| Slate-
Water is driven off by compaction and clays are compressed to form distinct
layers. |
| Phyllite-
Clays start to recrystalize into micas ( too small to see) - they give
the rock a sheen.
End of Low
Grade Metamorphism
|
| Schist-
Clays have fully recrystalized to visible micas and iron-aluminum silicates
are starting to recrystalize. Rock consists of mica flakes and layers surrounding
grains of other materials. |
| Gneiss -
Micas and other materials are reacting to form amphiboles and other less
platy minerals giving a more granular appearance to the rock.
End of Medium
Grade Metamorphism
|
| Granulite
- Extreme recrystalization to high temperature
& pressure forms resulting in a rock with large rounded/stubby grains.
further heating or pressure will result in melting and Granitization. |
