1. Chapter 10 Table of Contents Section 1 Continental Drift
Plate Tectonics
Table of Contents
Section 1 Continental Drift
Section 2 The Theory of Plate Tectonics
Section 3 The Changing Continents

2. Chapter 10 Wegener’s Hypothesis
Section 1 Continental Drift
Wegener’s Hypothesis
Continental drift the hypothesis that states that the continents once formed a single landmass, broke up, and drifted to their present location
Proposed by Alfred Wegener in 1912.
Fossil Evidence: fossils of the same plants and animals could be found in areas of continents that had once been connected.
Evidence from Rock Formations: ages and types of rocks in the coastal regions of widely separated areas matched closely.
Climatic Evidence: changes in climatic patterns suggested the continents had not always been located where they are now.

3. Wegener’s Hypothesis, continued
Chapter 10
Section 1 Continental Drift
Wegener’s Hypothesis, continued
Similar rock formations and fossil evidence supported Wegener’s hypothesis.
mid-ocean ridges
Sea-floor spreading
paleomagnetism

4. Chapter 10 1. Mid-Ocean Ridges long, undersea mountain chain
Section 1 Continental Drift
1. Mid-Ocean Ridges
long, undersea mountain chain
steep, narrow valley at its center
forms as magma rises from the asthenosphere
creates new oceanic lithosphere (sea floor) as tectonic plates move apart
Rocks closer to
Mid-ocean ridges
Younger
Less sedimented

5. Chapter 10 2. Sea-Floor Spreading Sea-floor spreading
Section 1 Continental Drift
2. Sea-Floor Spreading
Sea-floor spreading
The force of magma (molten rock) pushing up through cracks in the ocean crust along the mid-ocean ridges
As the ocean floor spreads apart, magma rises to fill the rift and then cools to form new rock.

6. Sea-Floor Spreading, continued
Chapter 10
Section 1 Continental Drift
Sea-Floor Spreading, continued

7. Sea-Floor Spreading, continued
Chapter 10
Section 1 Continental Drift
Sea-Floor Spreading, continued

8. Chapter 10 3. Paleomagnetism
Section 1 Continental Drift
3. Paleomagnetism
the study of the alignment of magnetic minerals in rock
Magnetic Reversals:
The earth generates a magnetic field –
• cooling magma with iron align themselves with the poles, much like a compass needle
• Earth's magnetic field is unstable and will flip every so often (hundreds of thousands to million of years).
Magnetic lineation on the sea floor, nearly identical patterns on either side of ridge

9. Paleomagnetism, continued
Chapter 10
Section 1 Continental Drift
Paleomagnetism, continued
Magnetic Symmetry
magnetic pattern on one side of a mid-ocean ridge is a mirror image to the other side.
indicate that new rock forms at the center of a ridge and then move away from the center in opposite directions.

10. Continental Drift (Pangaea)
Chapter 10
Section 1 Continental Drift
Continental Drift (Pangaea)

11. Chapter 10 Objectives Summarize the theory of plate tectonics.
Section 2 The Theory of Plate Tectonics
Chapter 10
Objectives
Summarize the theory of plate tectonics.
Identify and describe the three types of plate boundaries.
List and describe three causes of plate movement.

12. Chapter 10 How Continents Move
Section 2 The Theory of Plate Tectonics
Chapter 10
How Continents Move
plate tectonics the theory that explains how large pieces of the lithospehere, called plates, move and change shape
lithosphere the solid, outer layer of Earth that consists of the crust and the rigid upper part of the mantle
tectonic plates
include continental crust, oceanic crust, or both
Continents and oceans are carried along on the moving tectonic plates
About 15 tectonic plates

13. Chapter 10 Tectonic Plates
Section 2 The Theory of Plate Tectonics
Chapter 10
Tectonic Plates
asthenosphere the solid, plastic layer of the mantle beneath the lithosphere
made of mantle rock that flows very slowly
which allows tectonic plates to move on top of it

14. Tectonic Plates, continued
Section 2 The Theory of Plate Tectonics
Chapter 10
Tectonic Plates, continued
The boundaries of tectonic plates do not always match the outlines of continents.

15. 3 Types of Plate Boundaries
Section 2 The Theory of Plate Tectonics
Chapter 10
3 Types of Plate Boundaries
divergent boundaries
convergent boundaries
transform boundaries.

16. Types of Plate Boundaries, continued
Section 2 The Theory of Plate Tectonics
Chapter 10
Types of Plate Boundaries, continued
The boundary between tectonic plates that are moving away from each other
insert TT
Forms:
Rifts
mid-ocean ridges

17. Types of Plate Boundaries, continued
Section 2 The Theory of Plate Tectonics
Chapter 10
Types of Plate Boundaries, continued
insert TT
The boundary between tectonic plates that are colliding
Forms:
ocean trenches
Mountain ranges
Volcanoes
Island arcs

18. Types of Plate Boundaries, continued
Section 2 The Theory of Plate Tectonics
Chapter 10
Types of Plate Boundaries, continued
insert TT
The boundary between tectonic plates that are sliding one another
Earthquakes

19. Chapter 10 Causes of Plate Motion Convection
Section 2 The Theory of Plate Tectonics
Chapter 10
Causes of Plate Motion
Convection
is the movement of heated material due to differences in density that are caused by differences in temperatures.
Convection cell.
A cycle created by the cooler, denser water sinks, and the warmer water rises to the surface.
Mantle Convection
As the mantle material moves, it drags the overlying tectonic plates along with it.

20. Chapter 10 2 types of plate motion Ridge Push
Section 2 The Theory of Plate Tectonics
Chapter 10
2 types of plate motion
Ridge Push
As the cooling lithosphere sinks, asthenosphere moves away and pushes on the bottom of the plate.
Insert TT

21. Chapter 10 2 types of plate motion 2. Slab Pull
Section 2 The Theory of Plate Tectonics
Chapter 10
2 types of plate motion
2. Slab Pull
Cooled lithosphere becomes dense and sinks under (subduct into) asthenosphere in a process called slab pull
Insert TT

22. Section 2 The Theory of Plate Tectonics
Chapter 10
Plate Tectonics

23. Section 3 The Changing Continents
Chapter 10
Objectives
Identify how movements of tectonic plates change Earth’s surface.
Summarize how movements of tectonic plates have influenced climates and life on Earth.
Describe the supercontinent cycle.

24. Reshaping Earth’s Crust
Section 3 The Changing Continents
Chapter 10
Reshaping Earth’s Crust
1. rifting
the process by which Earth’s crust breaks apart
Heat from mantle builds up lithosphere becomes thinner
Cratons
stable rock contained in continents
older than 540 million years.
Sheilds – rocks within craton, exposed to earth’s surface

25. Reshaping Earth’s Crust, continued
Section 3 The Changing Continents
Chapter 10
Reshaping Earth’s Crust, continued
2. Continental Growth
terrane
a piece of lithosphere that has a unique geologic history
Terranes become part of a continent at convergent boundaries
Subducts under a lithosphere
Terrane is scraped off of the subducting plate – part of the continent
Look at figure 2 on pg 256

26. Effects of Continental Change
Section 3 The Changing Continents
Chapter 10
Effects of Continental Change
Climates
When continents move, the flow of air and moisture around the globe changes and causes climates to change.
Ice melts as continents move around
2. Change in life
populations of organisms are separated.
populations are separated, new species may evolve

27. The Supercontinent Cycle
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle
supercontinent cycle the process by which supercontinents form and break apart over millions of years
Pangaea
the supercontinent that formed 300 million years
began to break up beginning 250 million years ago

28. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued
1. Formation of pangea
Mountain ranges were formed
Panthalassa
the single, large ocean during Pangaea
Tethys Sea
cut into the eastern edge of Pangaea.
2. Breakup of Pangaea
About 250 million years ago Paleozoic Era
Broke into Laurasia and Gondwanaland.
Laurasia = North America and Eurasia.
Gondwanaland = Africa, South America, India, Australia, and Antarctica.

29. The Supercontinent Cycle
Chapter 10
The Supercontinent Cycle

30. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued

31. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued

32. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued

33. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued

34. In the future,
In about 150million years, African will collide with Eurasia
Australia will also eventually collide with Eurasia
In about 250million years, a new supercontinent will form

35. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued
Reading Check
What modern continents formed from Gondwanaland?

36. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued
Reading Check Answer
What modern continents formed from Gondwanaland?
The continents Africa, South America, Antarctica, and Australia formed from Gondwanaland. The subcontinent of India was also part of Gondwanaland.

37. The Supercontinent Cycle, continued
Section 3 The Changing Continents
Chapter 10
The Supercontinent Cycle, continued
Geography of the Future
As tectonic plates continue to move, Earth’s geography will change dramatically.
Scientists predict that in 250 million years, the continents will come together again to form a new supercontinent.

38. Chapter 10
Maps in Action
Maps in Action
Locations of Earthquakes in South America, 2002–2003

39. Chapter 10
Movements of the Ocean
Brain Food Video Quiz

40. Chapter 10 Multiple Choice
Standardized Test Prep
Multiple Choice
Which of the following factors is most important when determining the type of collision that forms when two lithospheric plates collide?
A. the density of each plate
B. the size of each plate
C. the paleomagnetism of the rock
D. the length of the boundary

41. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
Which of the following factors is most important when determining the type of collision that forms when two lithospheric plates collide?
A. the density of each plate
B. the size of each plate
C. the paleomagnetism of the rock
D. the length of the boundary

42. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
2. At locations where sea-floor occurs, rock is moved away from a mid-ocean ridge. What replaces the rock as it moves away?
F. molten rock
G. older rock
H. continental crust
I. compacted sediment

43. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
2. At locations where sea-floor occurs, rock is moved away from a mid-ocean ridge. What replaces the rock as it moves away?
F. molten rock
G. older rock
H. continental crust
I. compacted sediment

44. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
3. Which of the following was a weakness of Wegener’s proposal of continental drift when he first proposed the hypothesis?
A. an absence of fossil evidence
B. unsupported climatic evidence
C. unrelated continent features
D. a lack of proven mechanisms

45. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
3. Which of the following was a weakness of Wegener’s proposal of continental drift when he first proposed the hypothesis?
A. an absence of fossil evidence
B. unsupported climatic evidence
C. unrelated continent features
D. a lack of proven mechanisms

46. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
4. Which of the following statements describes a specific type of continental growth?
F. Continents change not only by gaining material but also by losing material.
G. Terranes become part of a continent at convergent boundaries.
H. Ocean sediments move onto land because of sea-floor spreading.
I. Rifting adds new rock to a continent and causes the continent to become wider.

47. Multiple Choice, continued
Chapter 10
Standardized Test Prep
Multiple Choice, continued
4. Which of the following statements describes a specific type of continental growth?
F. Continents change not only by gaining material but also by losing material.
G. Terranes become part of a continent at convergent boundaries.
H. Ocean sediments move onto land because of sea-floor spreading.
I. Rifting adds new rock to a continent and causes the continent to become wider.

48. Chapter 10 Short Response
Standardized Test Prep
Short Response
5. What is the name for the process by which the Earth’s crust breaks apart?

49. Short Response, continued
Chapter 10
Standardized Test Prep
Short Response, continued
5. What is the name for the process by which the Earth’s crust breaks apart? rifting

50. Short Response, continued
Chapter 10
Standardized Test Prep
Short Response, continued
6. What is the name for the layer of plastic rock directly below the lithosphere?

51. Short Response, continued
Chapter 10
Standardized Test Prep
Short Response, continued
6. What is the name for the layer of plastic rock directly below the lithosphere? the asthenosphere

52. The Himalaya Mountains
Chapter 10
Standardized Test Prep
Reading Skills
Read the passage below. Then, answer questions 7–9.
The Himalaya Mountains
The Himalaya Mountains are a range of mountains that is 2,400 km long and that arcs across Pakistan, India, Tibet, Nepal, Sikkim, and Bhutan. The Himalaya Mountains are the highest mountains on Earth. Nine mountains in the chain, including Mount Everest, the tallest above-water mountain on Earth, rise to heights of more than 8,000 m above sea-level. Mount Everest stands 8,850 m tall.
The formation of the Himalaya Mountains began about 80 million years ago. A tectonic plate carrying the Indian subcontinent collided with the Eurasian plate. The Indian plate was denser than the Eurasian plate. This difference in density caused the uplifting of the Eurasian plate and the subsequent formation of the Himalaya Mountains. This process continues today. The Indian plate continues to push under the Eurasian plate. New measurements show that Mount Everest is moving to the northeast by as much as 10 cm per year.

53. Reading Skills, continued
Chapter 10
Standardized Test Prep
Reading Skills, continued
7. According to the passage, what geologic process formed the Himalaya Mountains?
A. divergence
B. continental drift
C. strike-slip faulting
D. convergence

54. Reading Skills, continued
Chapter 10
Standardized Test Prep
Reading Skills, continued
7. According to the passage, what geologic process formed the Himalaya Mountains?
A. divergence
B. continental drift
C. strike-slip faulting
D. convergence

55. Reading Skills, continued
Chapter 10
Standardized Test Prep
Reading Skills, continued
8. Which of the following statements is a fact according to the passage?
F. The nine tallest mountains on Earth are located in the Himalaya Mountains.
G. The Himalaya Mountains are the longest mountain chain on Earth.
H. The Himalaya Mountains are located within six countries.
I. The Himalaya Mountains had completely formed by 80 million years ago.

56. Reading Skills, continued
Chapter 10
Standardized Test Prep
Reading Skills, continued
8. Which of the following statements is a fact according to the passage?
F. The nine tallest mountains on Earth are located in the Himalaya Mountains.
G. The Himalaya Mountains are the longest mountain chain on Earth.
H. The Himalaya Mountains are located within six countries.
I. The Himalaya Mountains had completely formed by 80 million years ago.

57. Reading Skills, continued
Chapter 10
Standardized Test Prep
Reading Skills, continued
9. Which plate is being subducted along the fault that formed the Himalaya Mountains?
A. The Indian plate is being subducted.
B. The Eurasian plate is being subducted.
C. Both plates are being equally subducted.
D. Neither plate is being subducted.

58. Reading Skills, continued
Chapter 10
Standardized Test Prep
Reading Skills, continued
9. Which plate is being subducted along the fault that formed the Himalaya Mountains?
A. The Indian plate is being subducted.
B. The Eurasian plate is being subducted.
C. Both plates are being equally subducted.
D. Neither plate is being subducted.

59. Interpreting Graphics
Chapter 10
Standardized Test Prep
Interpreting Graphics
Use the map below to answer questions 10 and 11. The map shows the locations of the Earth’s major tectonic plate boundaries.

60. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
10. What type of boundary is found between the South American plate and the African Plate?
A. convergent
B. divergent
C. transform
D. subduction

61. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
10. What type of boundary is found between the South American plate and the African Plate?
A. convergent
B. divergent
C. transform
D. subduction

62. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
11. What type of boundary is found between the South American plate and the African plate? What surface features are most often at boundaries of this type?

63. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
11. What type of boundary is found between the South American plate and the African plate? What surface features are most often at boundaries of this type?
Answers should include: the boundary between the South American plate and the African plate is a divergent boundary; most divergent boundaries are located on the ocean floor and produce mid-ocean ridges and underwater mountain ranges

64. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
Use the graphic below to answer questions 12 and 13. The graphic shows a strike-slip fault along a transform boundary.

65. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
12. What type of crustal interaction is indicated by the letter E?
F. continental rifting
G. sea-floor spreading
H. divergence
I. subduction

66. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
12. What type of crustal interaction is indicated by the letter E?
F. continental rifting
G. sea-floor spreading
H. divergence
I. subduction

67. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
13. Describe how a transform boundary differs from the boundaries shown by letters D and E in terms of plate movement and magmatic activity.

68. Interpreting Graphics, continued
Chapter 10
Standardized Test Prep
Interpreting Graphics, continued
13. Describe how a transform boundary differs from the boundaries shown by letters D and E in terms of plate movement and magmatic activity.
Answers should include: unlike the plates at a convergent boundary, shown by letter E, or divergent boundary, shown by letter D, plates at a transform boundary move past one another, not into or away from one another; transform boundaries produce a number of earthquakes, but they do not produce magma or cause mountain formation

69. Chapter 10
Tectonic Plates

70. Types of Plate Boundaries
Chapter 10
Types of Plate Boundaries

71. Ridge Push and Slab Pull
Chapter 10
Ridge Push and Slab Pull

72. Locations of Earthquakes in South America, 2002-2003
Chapter 10
Locations of Earthquakes in South America,