Rock Cycle http://www.uwgb.edu/dutchs/EarthSC-202VisualsIndex.HTM
Igneous Rocks Cool from the Molten State • Extrusive -- Erupted on Surface (volcanic) • Intrusive -- Solidify Within Earth (Plutonic) Large Grain Size ---> Slow Cooling • Extrusive Rocks -- Fine Grained • Intrusive Rocks -- Coarse Grained
Metamorphism Changes in Rock Composition or Texture Due to Heat, Pressure and Action of Fluids (like magma)
Contact Around Intrusions Shallow: 0-6 Km Low Pressure Local Regional Wide Areas 5-20 Km, Sometimes 30+ High Pressure Usually Accompained by Deformation Types of Metamorphism
Sedimentary Rocks Deposited on or Near Surface of Earth by Mechanical or Chemical Processes
Environmental Clues in Sedimentary Rocks • Fossils • Salt Water - Corals, Echinoderms • Fresh Water - Insects, Amphibians • Terrestrial - Leaves, Land Animals • Color And Chemistry • Red Beds - Often Terrestrial • Black Shale - Oxygen Poor, Often Deep Water • Evaporites – Arid Climates
Sediment Sizes and Clastic Rock Types Sedimentary rocks made of silt- and clay-sized particles are collectively called mudrocks, and are the most abundant sedimentary rocks.