Saturday, August 15, 2009

TYPES OF ROCKS



















What occurs in the Earth to change these rocks?


- Pressure from overlying rock layers
- High heat, but not enough to melt the rockRocks may be flattened or bent or atoms may be exchanged to form new mineral















You can think of metamorphic rocks as a squished peanut butter & jelly sandwich in your lunch.








How are metamorphic rocks classified?

- Non-Foliated—No bands are formed

- Example: marble formed from limestone













Non-foliated metamorphic rocks include marble, which comes from limestone, and quatzite, which comes from sandstone






- High temperatures and pressures at depth cause changes in mineralogy, texture, and composition
–Changes take place in Solid State by recrystallization and chemical reactions
–Temperatures greater than 250°, less than 700°
- Regional Metamorphism - High pressures and temperatures derive from regional collision, deformation and mountain building.
- Contact Metamorphism - Locally high temperatures, adjacent to intrusions.

Types of Metamorphic Rocks

























What is a metamorphic rock?

A metamorphic rock is any sedimentary or igneous rock that has been changed, or morphed, because of pressure and heat.
- Marble
- Schist

How is a metamorphic rock made?

Metamorphic rocks are made deep inside the earth where heat and pressure change the rocks











IGNEOUS ROCKS 1














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