1. Rocks

2. What is a Rock?
Any solid mass of mineral or mineral-like matter that occurs naturally as part of our planet
3 types
Igneous
Sedimentary
Metamorphic

3. The Rock Cycle
Interactions among Earth’s water, air, land, and living things can cause rocks to change from one type to another
A continuous process

4. Igneous Rocks Forms when lava or magma hardens Lava Magma
Molten rock on the surface of the Earth
Magma
Molten rock beneath Earth’s surface

5. Igneous Rocks are formed by
Cooling
Crystallization

6. Formation of Igneous Rocks
Intrusive Igneous Rock: forms when magma hardens beneath Earth’s surface
Ex: Granite
Extrusive Igneous Rock: forms when lava hardens on the surface of the Earth
Ex: Rhyolite

7. Classification of Igneous Rocks
Texture and composition are two characteristics used to classify igneous rocks

8. What is a Sedimentary Rock?
Forms when existing rocks are broken down into sediment then compacted and cemented together
Processes
Cementing
Compaction

9. Formation of Sedimentary Rocks
Weathering: Any process that break rocks into sediments
Erosion : The removal of weathered rocks
Deposition: when an agent of erosion (water, wind, ice, or gravity) loses energy, it drops the sediment
Compaction: is a process that squeezes or compacts sediments together
Cementation: takes place when dissolved minerals are deposited in the tiny spaces among the sediments

10. What is a Metamorphic Rock
Form when existing rocks are changed by heat and pressure
Metamorphism: means “change form”

11. Agents of Metamorphism
Heat: provides the energy needed to drive chemical reactions which causes existing minerals to recrystallize
Pressure: applied in all directions on a rock which causes spaces between mineral grains to close
Hydrothermal Solutions: hot, water based solutions that promote recrystallization by dissolving original minerals and then depositing new ones

12. Classification of Metamorphic Rocks
Classified by texture and composition
Foliated
Rock with layered or banded appearance
Ex: Gneiss
Nonfoliated
No layered or banded appearance
Contains only one mineral
Ex: Marble