1. Warm-Up: March 18, 2016
Write down everything you know about plate tectonics.

2. Unit Overview Four Sections Quiz on each section Plate Tectonics
Deformation of the Crust
Earthquakes
Volcanoes
Quiz on each section

3. Holt Earth Science Chapter 10
Plate Tectonics
Holt Earth Science
Chapter 10

4. Continental Drift
Continental drift is the hypothesis that continents once formed a single landmass, broke up, and drifted to their present location.
Proposed by Alfred Wegener in 1912
The single landmass is called a supercontinent.

5. Fossil Evidence of a Supercontinent

6. Rock Formation Evidence

7. Mountain Range Evidence

8. Glacial Debris Evidence

9. More Evidence Sea-floor spreading occurs at mid-ocean ridges.
Paleomagnetism, the alignment of magnetic materials in rocks, sometimes reverses.
Alternating bands of normal and reversed polarity help prove sea-floor spreading.
Satellite laser techniques.

10. Sea-Floor Spreading

12. Earth’s Layers

13. Earth’s Crust and Upper Mantle

14. Plate Tectonics
Asthenosphere is “plastic” rock that flows very slowly.
The lithosphere, located above the asthenosphere, is broken into tectonic plates.
Plates move at 2-17 cm/year

15. Tectonic Plates

16. Plate Boundaries
Divergent boundary: Where two plates are moving away from each other
Example: mid-ocean ridges
Convergent boundary: Where two plates are colliding
Can form volcanic arcs, island arcs, or mountains
Transform boundary: Where two plates are sliding horizontally past each other.
Example: San Andreas Fault

19. Warm-Up: March 21, 2016
What are the three different types of plate boundaries?
What is an example of each?
Try to do this without looking at your notes.

29. Causes of Plate Tectonics
Mantle Convection – most likely main driving force
Ridge Push – portion of convection near mid-ocean ridges
Slab Pull – portion of convection near subduction zones

30. Mantle Convection

31. Ridge Push

35. Warm-Up: March 21, 2016
What are the three different types of plate boundaries?
What is an example of each?
Try to do this without looking at your notes.

36. Think-Pair-Share Assign a vocabulary term to each letter

37. Think-Pair-Share Answers
A: Mantle convection
B: Ridge push, sea-floor spreading
C: Slab pull, subduction
D: Subduction zone, convergent boundary
E: Mid-ocean ridge, divergent boundary, sea-floor spreading
F: Magma
G: Volcanic arc, volcano

39. Warm-Up: March 22, 2016
Identify at least three pieces of evidence that support Wegener’s continental drift theory.
Define lithosphere.
Try to complete this without looking at your notes.

40. Warm-Up Answers Continental drift evidence
Fossil evidence
Rock formation evidence
Mountain range evidence
Glacial debris evidence
Sea-floor spreading
Paleomagnetism
Satellite laser measurements
Lithosphere: The outer portion of Earth, containing the crust and uppermost portion of the mantle.

41. Plate Tectonics Test 20 Questions Will be counted in the test category
All multiple choice (4 options)
All conceptual (no calculations)
1 point each
Will be counted in the test category
Vote on which day:
Wednesday/Thursday (45 minutes)
Friday (30 minutes)
Monday after break (45 minutes)

42. Continents
Cratons: Large area of stable rocks older than 540 million years.
Shields: Rocks within cratons exposed to Earth’s surface
Rifting: The process by which continents break apart.

44. Continental Rifting

45. Terranes
A terrane is a piece of lithosphere that has a unique geologic history that differs from the histories of the surrounding lithosphere.
A terrane becomes part of a continent through accretion.

46. Effects of Continental Change
Changes are affected by:
Location relative to equator/poles, other continents, oceans
Formation of mountains
Changes include:
Climate
Life

47. Supercontinent Cycle
Supercontinents break up and reform over millions of years
Pangaea: the supercontinent that formed 300 million years ago and began to break up 250 million years ago
Panthalassa was the ocean surrounding Pangaea
Pangaea initially broke into two continents
Laurasia – later broke up into North America, Eurasia
Gondwanaland – later broke up into South America, Africa, India, Australia, and Antarctica
In 250 million years, there will likely be a new supercontinent.

48. Supercontinent Cycle
Oceans go through cycles of spreading and subducting, causing Atlantic to widen (as it is now) and shrink (as it will in the future to form the next supercontinent).
Sea-floor age map:

49. Sea-floor Age

50. Pangaea Animations https://vimeo.com/14258924

52. The Other Future Supercontinent Theory

53. Assignment
10 – Plate Tectonics Assignment
Posted on web site