Study Guide ~~ Science! Plate Tectonics LithosphereEarths Interior

Mantle

Inner Core

Outer Core

To learn about Interior: geologists use direct evidence from rock samples and indirect evidence from seismic waves. Pressure inside Earth increases as you go deeper. Mantle: layer of hot rock The core is made our of nickel and iron Outer core= melted, but inner core is hotter but cannot melt because the pressure stops it from melting Convection currents cause the tectonic plates to move

Convection and the Mantle Convection: heat transfer by the movement of currents within a fluid Convection currents continue as long as heat is added. Without heat, convection currents eventually stop.

Drifting Continents Supercontinent: Pangaea All Lands Evidence from Land features & fossils & Climate Hypothesis made by Alfred Wegner Sea-floor-spreading Continually adds new material to the ocean floor. Sea floor spreads apart along both sides of a mid-ocean ridge as new crust is added Divergent Boundaries Evidence from molten material, magnetic stripes, drilling samples Ocean floor spreads the continents along its edges move As Subduction occurs, crust closer to a mid-ocean ridge and moves away from the ridge and toward a deep ocean trench The theory of Plate Tectonics Movement of convection currents in the mantle is the major force of plate motion. As plates move, they collide, pull apart, or grind past each other. (changes include volcanoes, mountain ranges, and deep ocean trenches) Convergent boundary: when two plates collide, the density of the plates determines which one comes out on top. Divergent boundary: Sea floor spreading and two plates move apart. Earthquakes Forces in Earths Crust Earthquakes & Seismic Waves P waves: compress and expand: fastest S waves: seismic waves that vibrate: slowest. Surface Waves: Combination: most damaging, slower than P and S How to measure earthquakes Mercalli Scale The Richter Scale The moment magnitude Scale Focus- where waves start & epicenter: point in the earths surface right above the focus.

Rocks Classifying Rocks Composition, color and texture Igneous Rocks Igneous Rocks: Forms from the cooling of magma or lava Extrusive rock- igneous rock formed from lava that erupted onto Earths surface Basalt: Most common extrusive rock Intrusive Rock: igneous rock formed when magma hardened beneath the Earths surface Heat and Pressure

Sedimentary Forms when particles of other rocks or the remains of plants and animals are pressed and cemented together. Weathering and Erosion and Deposition how sedimentary rocks form Weathering: breaking rocks down Erosion: moving from A to B by wind or water Deposition- You set them down, process by which sediment settles out of the water/wind carrying it.

Integrating Life Science: Rocks from Reefs Coral Reefs Limestone from Coral Reefs Organic Limestone deposits that began as coral reefs provide evidence of how plate motions have changed Earths Surface Metamorphic Rocks Metamorphic forms from other rocks that are changed by heat and pressure. Heat + Pressure deep beneath Earths surface can change any rock into metamorphic rock. Metamorphic can form out of igneous, sedimentary, or other metamorphic Foliated Rocks Metamorphic Rocks that have their grains arranged in a parallel layers or bands are said to be foliated. Describes most of the thin flat layering found in most metamorphic rocks, like slate, schist, and gneiss. None foliated Rocks The mineral grains are arranged randomly. Dont split in layers Marble & Quartzite = two examples Quartzite forms out of sandstone.

The rock cycle

Weathering and erosion

Lava

Weather and ErosionHeat and PressureHeat and pressureMetamorphicSedimentary IgneousMeltingMeltingMeltingMagma