Unit 5 - Rock Cycles

• Rocks: a solid mass of minerals or mineral like material. They are naturally occurring and each component material retains their own properties.
• Igneous: formed at a melt ( molten rock ). The 2 different types are intrusive and extrusive.
• Sedimentary: formed at the earth's surface by sediments and compression. The 2 types are clastic and chemical.
• Metamorphic: changed by pressure, temperature and fluids. The 2 types are foliated and non-foliated.
• Internal forces form Igneous and Metamorphic rocks.
• External forces form Sedimentary rocks.
• The interaction among Earth's water, air, land, and living things that cause rocks to change from one type to another.
• Internal Forces - forces within the Earth, heat and pressure.
• External Forces - outside the Earth, weathering and energy from the Sun.
• Intrusive Igneous Rocks - cool under the surface of the Earth. Cools slowly so they have large crystals. Ex: Granite.
• Extrusive Igneous - cool on the surface of the Earth, cools quickly so they have small crystals. Ex: Rhyolite.
• Igneous Rock Textures - coarse, fine, glassy, pophyrite
• Igneous Rock Composition - basaltic, andesitic, granitic
• Igneous Rocks - Granite, Rhyolite, Obsidion, Pumice, Gabbro
• Sedimentary Rock Forming Steps

  1. Weathering - any process that breaks rocks into smaller pieces/ sediments
  2. Erosion - the removal of rock ( may be by ice, wind, gravity, and weather )
  3. Deposition - sediments are dropped. Larger sediments drop before the smaller ones.
  4. Compaction - sediments are squeezed or compacted
  5. Cementation - dissolved minerals are deposited in the tiny spaces among the sediments
• Clastic - sedimentary rocks grouped according to size of the sediments in the rock.
• Sedimentary rocks can contain fossils and ripple marks
• On sedimentary rocks, lowest layers are the oldest and younger layers are on the upper levels
• Metamorphic Rocks - "change" form, happens under high pressure and temperature.
• Contact Metamorphism - when magma forces its way into rock, a low grade Metamorphism, changes are minor.
• Reigonal Metamorphism - when rocks are subjected to extreme pressures and temperatures during mountain building. This is a high grade Metamorphism.
• Foliated metamorphic rocks have a banded apperance.