8.9(A) Describe the historical development of evidence that supports plate tectonic theory.

1. Earth & Space 8.9(A) Describe the historical development of evidence that supports plate tectonic theory. Evidence for plate tectonics The match in shape between the east coast of South America and the west coast of Africa suggests both were once part of a single continent. There are similar patterns of rocks and similar fossils on both sides of the Atlantic - including the fossil remains of land animals that would have been unable to swim across an ocean.

2. Structure of the Earth The Earth is made up of 3 main layers: • Core • Mantle • Crust Mantle Outer core Inner core Crust

3. The plates are moving at a speed of 1 to 10 cm per year. The crust is not a solid shell; it is broken up into huge, thick plates.

4. The Movement of theEarth's Plates • The cause of • earthquakes, volcanoes, mountain range formation, and many other crustal features.

5. Plate Tectonics Puzzle Preview Solve the puzzle to discover what the Earth looked like 220 million years ago. What’s the Code? Use the legend to identify the symbols on each island or continent. Puzzle me this. Look at the shapes of continents and islands. What landmasses seem to fit together? Let’s rock! Examine the evidence and try to match up landmass boundaries that show similar rock strata, fossilized desert belts, and dinosaur fossils. Hold that pose. Look over the arrangement of the continents and islands and decide if the position of any of them should change. When you are satisfied with your map of Pangaea, tape or glue it down on he world map.

9. Plate Tectonics Puzzle Analysis Answer these questions: 1. Rock type, fossils, glacial deposits, and glacier "tracks", are four types of ........ that support the theory of plate tectonics. 2. Explain why similar fossils can be found on opposite sides of an ocean, when there is no way the organisms could have traveled that far when alive. 3. Explain why fossils of tropical animals are found in Antarctica even though the poles of the Earth have never been warm.

10. The supercontinent Pangaea Wegener hypothesized that there was a gigantic supercontinent 200 million years ago, consisting of all of Earth’s land masses, which he named Pangaea, meaning "All-earth".

11. ALFRED WEGENER AND PANGAEA In 1915, the German geologist and meteorologist Alfred Wegenerfirst proposed the theory of continental drift, which states • that parts of the Earth's crust slowly drift atop a liquid core.

12. evidence Puzzle-fit of Land Masses

13. 225 million years ago 200 million years ago 135 million years ago 65 million years ago Present Day

14. 2. Fossil Evidence Alfred Wegener traveled the world, and noticed... Fossils of Mesosaurus (one of the first marine reptiles, even older than the dinosaurs) were found in both South America and South Africa. ...matching rocks and fossils on distant coastlines.

15. 3. Convection currents beneath the plates move the crustal plates in different directions. A convection current flows from hottest tocoolestin the mantle.

16. For Understanding EARTH'S HISTORY A) Using the diagram, identify two pieces of evidence that support the scientist's theory that the land masses were once together. • ANSWER: (puzzle-fit of land masses, matching rock and fossil territories on distant shorelines)

17. Earth & Space 8.9(B) Relate plate tectonics to the formation of crustal features. Plate tectonics explained why earthquakes and volcanoes were concentrated in specific places - around the boundaries of moving plates.

18. Plate Tectonics Name__________________________ Date_________________Period_____ • Divergent Plate Movement: • Seafloor spreading is the movement of two _________ plates away from • each other. The top layer of the Earth's surface is called the ________. • Results in the formation of • new oceanic _________along a mid-ocean ridge. _________is constantly being created and destroyed. __________ crust is more active than __________crust. • Convergent Plate Movement: • When two plates collide • When two oceanic plates collide, one may be pushed under the other and magma from the mantle rises, forming ___________. When an oceanic plate collides with a continental plate, the oceanic plate is forced under the continental plate; this is called _______________. When two continental plates collide, ____________ _________ are created. • Transform Plate Movement: When two plates move sideways against each other, an __________________ is produced. • Most of the Earth's seismic activity (volcanoes and earthquakes) occurs at the plate boundaries as they interact.

19. The top layer of the Earth's surface is called the crust. Crust is constantly being created and destroyed. Oceanic crust is more active than continental crust.

20. Most of the Earth's seismic activity (volcanoes and earthquakes) occurs at the plate boundaries as they interact.

21. Divergent Plate Movement: Seafloor spreading is the movement of two oceanic plates away from each other. • Results in the formation of new oceanic crust (from magma that comes from • within the Earth’s • mantle) along a • mid-ocean ridge.

22. Divergent Plate Movement: Seafloor Spreading Ocean Ridge Ocean Oceanic Crust Mantle Magma Asthenosphere

23. Convergent Plate Movement: • When two plates collide When two oceanic plates collide, one may be pushed under the other and magma from the mantle rises, forming volcanoes. When an oceanic plate collides with a continental plate, the oceanic plate is forced under the continental plate; this is called subduction.

24. Convergent Plate Movement: • When two plates collide Two Continental Plates- When two continental plates collide, mountain ranges are created.

25. Convergent Plate Movement: Subduction Volcanos Subduction Zone Continental Crust Ocean Oceanic Crust Mantle Magma Aesthenosphere

26. Transform Plate Movement: When two plates move sideways against each other, an earthquake is produced.

27. Continental 1. Which type of plate is older? Mantel Pangaea 2. Which type of plate is thicker? 4. What is it called when one plate is pushed under another plate as they collide? 3. What is it called when two oceanic plates move apart and new crust is formed? Exit Ticket Challenge: Number your paper 1-9. Match each definition with the correct term. Mountain Range Wegener 5. What can form when two continental plates collide? Oceanic 6. What do plates float on? 7. New crust is created by _____? Magma Subduction 8. Who first proposed the theory of continental drift? 9. What is the name of the supercontinent that formed from about 200 to 100 million years ago? Seafloor Spreading