Chapter 3 Rocks
Rocks Any solid mass of mineral or mineral-like matter that occurs naturally Most rocks are MIXTURES of minerals Some rocks contain nonmineral material (shells, plants, bones, etc.) Some rocks do not have crystalline structures
Classification of rocks Rocks are classified based on how they were formed. Three classifications Igneous – form when magma or lava cools and hardens Sedimentary – form when sediments are compacted and cemented Metamorphic – form when rocks are changed by extreme heat and pressure
Rock cycle Shows relationships between different rock forms All rocks can be changed from one kind to another Ex. Igneous rocks can become sedimentary rocks through weathering and erosion The Rock Cycle shows how these changes can take place.
Rock cycle