2 Section 1 Continental Drift Alfred Wegener( )Proposed hypothesis of continental driftPangaea
3 Evidence to support C.D.Continents appear to fit together like a puzzleSimilar fossils have been found on different continentsRemains of warm climate plants in arctic zones and Arctic clues in tropical zonesSimilar rock structures found on different continents
4 Section 2: Seafloor Spreading Magma below Oceanic crust pushes upward and outward forcing the crust into large underwater mountain ranges.Mid Ocean Ridges
5 Evidence for S.F.S A theory Has been proven to occur Rocks increase in age as one moves away from the mid-ocean ridges.Continents are measure farther apart by 1 or 2 inches per yearoldnew
6 Section 3: Theory of Plate Tectonics Combines the hypothesis of continental drift with the theory of sea floor spreading.Earth’s crust and upper mantle broken into plates.Shift on layer of molten rock.
7 Earth’s plates Lithosphere Asthenosphere Earth’s crust and upper mantleLayer that shiftsAsthenosphere-like layerof mantle.
8 Earth’s crust Continental crust Oceanic crust Thick Less dense Older Forms landOceanic crustThinDenseYoungerForms ocean bottom
9 Plate Boundaries Divergent Where 2 plates move apart Sea floor spreading!Mid-Atlantic ridgeRift Valley