Rocks and The Rock Cycle
Three Types of Rocks Igneous Sedimentary Metamorphic
Igneous Rocks Formed when molted rock (lava or magma) cools and hardens Two types of Igneous Rocks Intrusive : cooled slowly beneath the surface, contains large crystals Extrusive: cooled rapidly on the surface, contains small crystals
? Intrusive Extrusive
Sedimentary Rocks 1st the rocks are weathered and eroded by wind and water (This means the rock is broken down into little particles called sediment. The sediment is then carried away by wind and water.)
Sedimentary Rocks 2nd the sediment is deposited in layers (This means the sediment is dropped. Over time this forms layers of different sediment.)
Sedimentary Rocks 3rd the layers are compacted and cemented together forming sedimentary rock. (This means the sediment is squeezed and glued together.)
Sedimentary Rocks
Metamorphic Rocks Formed when rocks undergo a structural change due to Heat and Pressure
The Rock Cycle
Quick Check Metamorphic Rock is rock whose structure has changed. What factors change the rock? A. heat and pressure B. compaction and cementation C. cooling of magma
Quick Check 2. An active volcano on a Pacific island spews out lava. When it cools, what has been formed? A. metamorphic rock B. sedimentary rock C. igneous rock
Quick Check 3. What type of igneous rock is shown below? A. Intrusive B. Extrusive C. Sedimentary WHY?????
Quick Check What is the correct order of steps that form sedimentary rock? A. compaction & cementation, weathering & erosion, deposition B. weathering & erosion, deposition, compaction & cementation C. deposition, compaction & cementation, weather & erosion
Molten or “melted” rock Quick Check 5. Where does magma or lava come from? Molten or “melted” rock