metamoRPHIC ROCKS
Metamorphic rocks are one of the the three main types of rocks. They are made deep under the earth's surface. They change form due to pressure and heat. The pressure inside the Earth is the result of gravity pulling down the Earth's crust. Pressure, like heat, increases with depth. In order for metamorphism to occur, the formation of metamorphic rocks, energy is needed to fuel the chemical reactions. the energy used in metamorphism is mainly heat energy. The heat and pressure prevents the rock from breaking and cracking. The mineral grains become realigned and they flatten out and get longer.
Characteristics of Metamorphic Rocks
Examples of Metamorphic Rocks
Characteristics of Metamorphic Rocks
- Classified by texture and composition.
- Rarely has fossils.
- May react with acid.
- May have alternate bands of light and dark minerals.
- May be composed of only one mineral, ex. marble & quartzite.
- May have layers of visible crystals.
- Usually made of mineral crystals of different sizes.
- Rarely has pores or openings.
- May have bent or curved foliation.
Examples of Metamorphic Rocks
- Marble - is a metamorphic rock that comes from metamorphosed limestone or dolomite.
- Quartzite - is a coarse-grained metamorphic rock derived from sandstone.
- Slate - is a fined grained metamorphic rock.
- Phyllite - is a fined grained metamorphic rock.
- Schist - is a coarse grained metamorphic rock.
- Gneiss - is a medium to coarse grained metamorphic rock.