1. Chapter 2: Canada’s Physical Landscape

2. Formation of the Earth 2.1 Planet Earth Formation of the Earth 2.1

3. Formation of the Earth’s Interior @5 billion years ago, plantesimals (meterorites,icy comets) collide  heat released (Kinetic energy to thermal energy) Entire planet melts (still cooling today) Gravity sorts materials by density –Fe (iron) in center –All other compounds towards surface

4. Earth’s Four Layers Crust Mantle Outer Core Inner Core

5. Scrat!

8. The Crust Outer layer 5-100 km thick 2 types of crust –O–Oceanic (very dense) –C–Continental (less dense)

9. The Mantle Middle layer Very thick layer

10. The Core Made mostly of iron 1/3 of the earth’s mass Very hot

11. Earth’s Layers How are the earth’s layers similar to an egg? Shell=crust Egg white=mantle Yolk=core

13. The Earth’s Interior Distance: 6730 km (3963 miles)

14. What is ‘ Plate Tectonics’? From Greek ‘tektonikus’ meaning building or construction Plate tectonics refers to the process of plate formation, movement, and destruction.

15. How the Plates Moved….

16. Tectonic Plates Earth’s crust is broken into about 19 pieces These plates move on top of the crust.

17. Geography of the Plates

18. 1915 Alfred Wegener proposes theory of continental drift. Supercontinent Pangaea (‘all-earth’) [225mya]. Continents ‘broke apart’ and moved into current positions.

19. Plate Movement History

20. Evidence for Continental Drift? Wegner’s evidence –Fit of continents –Match of magnetic bands on rocks on either side of the Mid-Atlantic Ridge –Fossil plants, animals, rock types / geology match on opposite shores deposits inconsistent with current geography

21. Glacial deposits, including structures that indicate ice flow direction are located in ancient rocks as shown on the left. Wegener suggested that the pattern formed with continents together at the south pole.

22. Striking Match of Biological Regions

23. The Theory of Continental Drift

24. Matching Mountain Chains

25. Striking Match of Geologic Regions

26. The Mid-Atlantic Ridge…

27. Mid-Atlantic Ridge ‘In Action’!

28. Sea Floor Spreading

29. Bill Nye

32. Plate Margins: how do we know? Marked by volcanic and tectonic activity

33. Crustal Processes –Destruction (subduction) –Creation (volcanism) –Alteration / deformation (folding and faulting)

34. Subduction Zone?

35. Subduction Zones Activity: –Subduction zone; shallow to deep earthquakes; volcanism (continental) Examples: –ocean trench (Pacific Ocean by Japan); explosive volcanic mountains ‘Ring of Fire’

36. Subduction Zones

37. How Might the Continents Look in the Future?