Plate Tectonics Review

1. Plate Tectonics Review Chapter 8

2. The ______________ is made of partially melted, “plastic” rock material and plates “float” on it.

3. asthenosphere

4. At subductionboundaries one plate __________________ another plate

5. Subducts/plunges/ sinks below

6. A transform boundary is when ___________.

7. Two plates slide past each other at a fault

8. The East-African Rift/Red Sea are examples of a ___________________

9. Rift valley that formed at a continental-continental divergent boundary

10. Why does magma rise?

11. It is less dense than the surrounding material

12. Some ________________ rocks contain iron-based magnetic minerals that “record” the direction of Earth’s magnetic field when the rock formed.

13. igneous

14. Mid-ocean ridges are broken into sections that are offset from each other by breaks called __________________ that are perpendicular (at right angles) to the ridge and are the source of earthquakes here.

15. Fracture zones

16. In 1912, Alfred Wegener proposed the hypothesis of ______________________, which stated the continents have moved over time.

17. Continental drift

18. As you move out from the center of a mid-ocean ridge, what happens to the temperature of the rock?

19. Hottest rock is at the center, coolest rock is furthest out

20. An example of a (mid-) ocean ridge is _________________.

21. Mid-Atlantic Ridge • East Pacific Rise

22. Plate tectonics provides evidence/an explanation for the location/occurrence of: • 1. • 2. • 3.

23. 1. volcanoes • 2. earthquakes • 3. the formation of new crust (sea floor)

24. When Earth’s magnetic field “matches” up with the geographic poles is known as _______________ polarity • Ex. magnetic north & geographic north match up and magnetic south & geographic south match up

25. normal

26. A ________________ is the border between 2 diverging plates.

27. Rift valley

28. As you move out from the center of the mid-ocean ridge, what happens to the age of the rocks?

29. They go from younger to older

30. 1 2 • Label the layers… 3 4

32. Convergent boundaries are when 2 plates ___________________

33. Move towards each other

34. Name the 3 ways that plates can move in relation to one another

35. Away from each other (divergent plate boundary) • Towards each other (convergent plate boundary) • Slide past each other (transform plate boundary)

36. An example of a deep-sea trench is the ____________ trench

37. Marianas • Peru-Chile • Tonga • Aleutian

38. When Earth’s magnetic field does not “match” up with the geographic poles is known as _______________ polarity • Ex. magnetic north & geographic south match up and magnetic south & geographic north match up

39. Reversed

40. The ___________ is made up of the crust & uppermost mantle and is broken into “plates”

41. lithosphere

42. What are 3 features/effects found at oceanic-oceanic convergent plate boundaries. • 1. • 2. • 3.

43. 1. trenches • 2. volcanic island arcs (on the overriding plate) • 3. earthquakes (shallow to very deep)

44. What is the Ring of Fire?

45. A ring of many active volcanoes around the Pacific plate’s boundaries

46. (Mid-) ocean ridges form at ___________ plate boundaries

47. Oceanic-oceanic divergent

48. Some of the observations that support the hypothesis of continental drift are: • 1. • 2. • 3. • 4.

49. 1. shape of continents (“puzzle fit”) • 2. fossils • 3. distinctive rock formations • 4. climate change evidence (ex. coal deposits)

50. At a continental-continental divergent boundary, a ________ forms.