3. Fun Earth Facts Highest mtn: Mt. Everest 8,848m Lowest point: Dead Sea 393m bsl Longest river: Nile 6,690km Largest desert: Sahara 9,000,000 km sq.

4. 3 Types of Rocks Sedimentary: Rocks made of sediments (soil, sand, other rocks) Metamorphic: Rocks made of existing rocks under heat and pressure Igneous: Rocks from lava or molten rock (from volcanoes)

5. Geologic Time Scale Definition: Chart used to describe the earth’s history through time The time periods of the earth are divided into 4 main eras: * Precambrian: largest era * Paleozoic * Mesozoic * Cenozoic

6. Putting the Pieces Together: Part II Wegener: meteorologist who theorized that the continents were once joined together in a single continent Pangaea: name given to the “supercontinent” described by Wegner

7. Putting the Pieces Together (cont.) Theory of continental drift: Wegner’s theory that continents known today were once joined together as one *Based on : fossil evidence, shapes of cont. fitting together, and study of climates Plate: large masses of the earth’s crust moving in various directions—they “ride” on the mantle Plate tectonics: the theory of how the continents move, based on Wegner’s theory of continental drift

8. The Layers of the Earth Part III 1. Crust: the thin, rocky, outer portion of the earth’s surface 2. Mantle: composed of 2 layers a. Lithosphere: where plates are b. Asthenosphere: slushy layer 3. Core: solid, inner layer (almost pure iron)

9. Moving Plates: Part IV *Currents in the mantle that move the plates are caused by heat Plates can move in one of 3 ways: 1. Converge/Collide: approach each other/hit * when they collide, they form: a. Trench (deep valley) where old crust is re-cycled

10. Moving Plates: Part IV b. Volcanoes c. mountains 2. Separate: move away from each other *causes deep cracks called rifts to form ex. mid-ocean ridge & Great Rift Valley

11. Moving Plates cont. *sea-floor spreading: a process during which new ocean crust is formed at mid- ocean ridges (large mountains on ocean floor where new crust is formed) *On the ocean floor at the spreading center, new crust is formed 3.Slide past each other *faults form like the San Andreas Fault *earthquakes are common along these plate boundaries