Metamorphic Grade
Metamorphic Rock Classification
Outline
There are a limited number of common metamorphic rock types:
| ROCK NAME | TYPE | PARENT ROCK | CHARACTERISTICS |
|---|---|---|---|
| SLATE | foliated | shales and muds | prominant splitting surfaces |
| SCHIST | foliated | fine grained rocks | mica minerals, often crinkled or wavy |
| GNEISS | foliated | coarse grained rocks | dark and light bands or layers of aligned minerals |
| QUARTZITE | non-foliated | sandstone | interlocking almost fused quartz grains, little or no porosity |
| MARBLE | non-foliated | limestone | interlocking, often coarse, calcite crystals, little or no porosity |
Contact metamorphic rocks are recrystallized and rarely show foliation. Shales baked by igneous contact form very hard fine-grained rocks called HORNFELS. Calcareous rocks (dirty limestones) when subject to contact metamorphism an alteration by hot fluids produce rocks called SKARNS.
Metamorphic Grade
Metamorphic Rock Classification
Outline