12/15/14 PM Review Please pull out study guide and a piece of paper to take notes. Finals • 100 ?’s scan tron • 85 minutes to take test Earth Science Review Concepts • • • • • • • • Layers of Earth Convection Plates Minerals Rocks Earthquakes Relative Dating Science basics 5.1 Earth’s Interior 1. What are the characteristics of Earth’s crust, mantle, and core? 5.1 Earth’s Interior 2. What is the composition of each layer of the Earth Crust = solid rock on land and ocean floor Mantle = very hot, solid rock Core = Iron & Nickel 5.2 Convection and the Mantle 1. How is heat transferred? Through convection currents 5.2 Convection and the Mantle 2. What causes convection currents and relation to density? Hot rises, cool sinks 5.2 Convection and the Mantle 3. What causes convection currents in the mantle? 4. How do convection currents relate to plate tectonics? 5.5 The Theory of Plate Tectonics 1. What is plate tectonics? The theory that pieces of Earth’s lithosphere are in constant motion, driven by convection currents and oceanic crust 5.5 The Theory of Plate Tectonics 2. What evidence supports the theory? • • • • • Rock formations Physical evidence on crust Earthquakes/volcanoes Fossils Magnetic strips 5.5 The Theory of Plate Tectonics 3. What causes the movement of Earth’s lithospheric plates? Convection currents plates to move 5.5 The Theory of Plate Tectonics 4. What forms as a result of movement of plates at each boundary? Divergent = rift valley, mid ocean ridge (sea floor spreading) Convergent = subduction - trench; colliding mountains 5.5 The Theory of Plate Tectonics 5. What processes are involved in the movement of the Earth’s plates that causes volcanoes and earthquakes? Volcanoes = boundaries of plates subduction zones divergent areas hot spots 5.5 The Theory of Plate Tectonics 5. What processes are involved in the movement of the Earth’s plates that causes volcanoes and earthquakes? Earthquakes = stress from plates convergent transform 5.5 The Theory of Plate Tectonics 6. What is subduction? How does a trench form? 3.1 Properties of Minerals 1. What is a mineral SNIFC Solid Naturally Occurring (not man made) Inorganic (non living) Formula (consistent chemical formula – not a rock) Crystal structure 3.1 Properties of Minerals 2. Properties Color • Easy to observe • Not always a clear way to identify Streak • Streak: the color of its powder • Colors of minerals may vary but streak does not Luster • Luster: how much light is reflected from a mineral’s surface Metallic - Galena Glassy - Topaz Waxy, greasy, or pearly - Talc Submetallic/dull graphite Silky - Malachite Earthy - Hematite Density • Density: how much mass there is in a given space • D = m/v or water displacement Hardness • Hardness: determined by a scratch test – A mineral can scratch any material softer than itself – But can be scratched by any mineral that is harder – Mohs hardness scale Mohs Hardness Scale Crystal Systems • Crystal system: the structure of how the mineral’s atoms form • Ex: cubic, hexagonal, rhombic Cleavage • Cleavage: when a mineral splits along a flat surface • Ex: Mica Fracture • Fracture: when a mineral breaks apart in an irregular way Special Properties • Some minerals are identified by special physical/chemical properties. Review 1. 2. 3. 4. 5. 6. 7. 8. 9. Color Streak Luster Density Hardness Crystal system Cleavage Fracture Special properties Answers: A. Usually not a clear identifier B. Does not break in a flat sheet C. Calcite’s powder is always white D. Fluorescent E. Breaks in flat sheets F. Shiny mineral G. Cubic shape H. Compares how it is scratched/scratches I. How much mass takes up a certain volume 1. A 2. C 3. F 4. I 5. H 6. G 7. E 8. B 9. D 3.1 Properties of Minerals 4. Be able to read a chart and determine the identity of a mineral. 4.1 Classifying Rocks 1. How are rocks identified? • How they’re formed • Composition • Texture 4.1 Classifying Rocks 2. What are the 3 main groups of rocks? 1. Igneous 2. Sedimentary 3. Metamorphic 4.2 Igneous Rocks 1. How are they formed Magma cooling and hardening 4.2 Igneous Rocks 4. How does the rate of cooling affect the texture? Intrusive vs. Extrusive Intrusive = cooled slowly inside the earth (larger crystals) Extrusive = cooled rapidly outside the earth (small crystals, air pockets 4.2 Igneous Rocks 2. Characteristics • Large visible crystals • Glasslike • Holes from air bubbles while cooling Igneous Rocks Coarse-Grained Fine-Grained Felsic Granite Rhyolite Mafic Gabbro Basalt 4.3 Sedimentary Rocks 1. How do they form Sediment = weathering and erosion Deposition Compaction & cementation 4.3 Sedimentary Rocks 2. Characteristics: • Appearance of sand, pebbles, rocks cemented together • Layers (usually only noticed in large specimen) • Appearance of fossils 4.5 Metamorphic Rocks 1. How are metamorphic rock formed? Heat and pressure 4.5 Metamorphic Rocks 2. Where does the heat and pressure come from? Deep inside the earth (magma) 4.5 Metamorphic Rocks 3. Characteristics: • Ribbon-like lines, in thin parallel or wavy lines • TINY crystals that line up in the same direction • Very hard, usually can scratch metal 4.6 The Rock Cycle 1. What is the rock cycle? 2. What are the possible stages in the rock cycle? 3. Processes that occur when a rock changes 4.6 The Rock Cycle • What are some of the causes for weathering and erosion Breaks down rocks into little pieces = WEATHERING Moves the sediment = EROSION Weathering Erosion • Mechanical Weathering (FRAPA) – Freezing & Thawing F – Release of pressure R – Animal Actions A – Plant P Growth – Abrasion A • Chemical Weathering (LOWCA) – Living Organisms L – Oxygen O – Water W – Carbon Dioxide C – Acid A Rain – Examples Erosion moves rock particles • Sediment = rock particles • Deposition = when sediment is laid down/deposited from erosion • Examples: WWGM – “What would G-ma make?” – Wind – Water (runoff, rivers, waves) – Glaciers – Mass Movement • (landslides, mudflows, slumps and creeps) 5.2 Earthquakes & Seismic Waves 1. What causes an earthquake? Stress built up from plates moving 6.2 Earthquakes & Seismic Waves 2. How does the energy of an earthquake travel through Earth? Seismic Waves P S Surface 6.2 Earthquakes & Seismic Waves 3. What are the scales used to measure the strength of an earthquake? Richter – size of seismic waves Mercalli - damage Moment Magnitude – magnitude of energy (#) 6.2 Earthquakes & Seismic Waves 4. How do scientists locate the epicenter of an earthquake? 7.1 Volcanoes and Plate Tectonics 1. Where are most of Earth’s volcanoes found Along the edges of plate boundaries divergent subduction zones 10.1 Fossils 1. What is a fossil? Fossil = preserved remain or trace of a living thing 10.1 Fossils 2. How does a fossil form? Most fossil form when living things die and are buried by sediments Sediment slowly hardens into rock and preserves the shape of the organisms 10.2 Relative Dating Relative Age = when a rock is compared to the ages of other rocks/fossils 10.2 Relative Dating 1. Given a certain cross section of rock, indicate which layers were deposited first to last Oldest usually on bottom, Youngest on top 10.2 Predict the environment E – Shale (shark) B – Sandstone (tracks) I – Shale (shark fossils) F – shale (fish) G - Fault C - Magma A - Conglomerate H – Shale (shark) D – Metamorphic 10.2 Environment… • • • • • • • • • Intrusive Igneous: Magma inside cooling, crystals Extrusive Igneous: Lava cooling outside Green Shale (sed): Murky, muddy sea Red Shale (sed): Plains with streams Sandstone: Desert Limestone: Clear water sea Conglomerate: Flood, mudslide, landslide Wavy rocks (met): Plates colliding Coal: Forest with lots of plants 10.2 Fossils • • • • • • • • • Intrusive Igneous: NONE Extrusive Igneous: NONE Green Shale (sed): Trilobites, Brachiopods, Crinoids Red Shale (sed): Reptiles & Insects Sandstone: Tracks Limestone: Fish, Sharks, Sponges Conglomerate: Rocks, pebbles, boulders Wavy rocks (met): NONE Coal: NONE 10.2 Predict the environment E – Shale (shark) B – Sandstone (tracks) I – Shale (shark fossils) F – shale (fish) G - Fault C - Magma A - Conglomerate H – Shale (shark) D – Metamorphic E – Deep Ocean B – Desert I – Deep Ocean F – River Bed G - Earthquake C - Extrusive A - Mudslide H – Deep Ocean D – Plates Colliding E – Shale (shark) B – Sandstone (tracks) I – Shale (shark fossils) F – shale (fish) G - Fault C - Magma A - Conglomerate H – Shale (shark) D – Metamorphic 1.1 What is science? 1. What is the difference between qualitative & quantitative? Qualitative is descriptive Ex: The block is blue Quantitative is numerical Ex: The block has a mass of 22 g. Questions?