2 “Metamorphic”“Metamorphic” means Change!Biochemical LimestoneMarble
3 Metamorphic Rock Sources Metamorphic rocks are formed when:1.Igneous2. Sedimentary or3. Pre-existing Metamorphic rocks arechanged
4 Metamorphic Rock Classification Metamorphic Rocks are classified based on:1. Formation Conditions (where formed)2. Texture3. Parent Rock (what rock, or rock type, it came from)Quartzite- Fine GrainedGneiss- Foliated
5 Common Metamorphic Rocks Rock NameParent RockSlateShale or MudMicaGneissGraniteQuartziteSandstoneMarbleLimestone
13 What Causes Metamorphic Rocks to Form? Metamorphic Rocks are formed when preexisting rocks are changed by:HeatPressureAnd
14 Sources of HeatIncrease in Temperature due to Deep Burial (20-30 degrees Celsius per kilometer below the surface). Due to radioactive decay.----Regional- MetamorphismIncrease in Temperature due to Plate Friction ( degree Celsius per km below the surface) Dynamic MetamorphismIntrusion by hot Magma. ----Contact Metamorphism
15 Sources of PressureWeight of Overlying Rocks (1 cubic foot of granite weighs 167 pounds)Created by converging plates (Converging- Boundaries) or thoseTransform Boundaries (side-by-side movement)
16 Effects of Metamorphism on Rocks Impurities such as holes and fossils destroyed.
17 Effects of Metamorphism on Rocks Pore Space between grains is lost due to Compression.Rock density increases.
18 Effects of Metamorphism on Rocks Mineral Grains are flattened, enlarged and elongated.