Metamorphic Rocks: Formation and Classification

1. LEQ: What are metamorphic rocks, how do they form, and how are they classified? Lesson terms: foliated, non-foliated.

2. Metamorphic Rock • Every metamorphic rock is a rock that has changed its form. • The word metamorphic comes from the Greek language. • In Greek meta means “change”. • In Greek morphosis means “form”.

3. Metamorphic Rock • Heat and pressure deep beneath Earth’s surface can change any rock into metamorphic rock. • Sometimes, forces inside the Earth can push the rock down toward the heat of the mantle. http://www.phschool.com/atschool/science_activity_library/images/earths_interior.jpg

4. Metamorphic Rock • When rock changes into metamorphic rock, its appearance, texture, crystal structure and mineral content change. • Metamorphic rock can form out of igneous, sedimentary, or other metamorphic rock.

5. Metamorphic Rock • Geologists classify metamorphic rocks by the arrangement of the grains that make up the rocks. • If grains are lined up in parallel layers or bands, they are said to be foliated. • If grains are randomly arranged with no layers, or bands, they are said to be non-foliated.

6. Foliated Metamorphic Rocks Slate Schist http://www.inspect-ny.com/roof/slate29.jpg Gneiss http://farm4.static.flickr.com/3140/2688358095_c968a7df0b.jpg?v=0 http://www.daviddarling.info/images/quartzite.jpg

7. Non-Foliated Metamorphic Rocks White Marble Pink Quartzite http://www.inspect-ny.com/roof/slate29.jpg http://farm4.static.flickr.com/3140/2688358095_c968a7df0b.jpg?v=0

8. Metamorphic Rock Igneous or Metamorphic Sedimentary *Granite Gneiss *Shale Slate *Sandstone Quartzite *Limestone Marble * Parent Rock.