2. Chapter Menu Lesson 1: Interaction at Plate Boundaries
Lesson 2: California Geology
Click on a hyperlink to view the corresponding lesson.

3. 5.1 Interactions at Plate Boundaries
fracture
fault
divergent plate boundary
continental rifting
rift valley
convergent plate boundary
subduction
transform plate boundary

4. Stress and Deformation
5.1 Interactions at Plate Boundaries
Stress and Deformation
Earth’s lithosphere is made up of crust and upper mantle that are broken into plates.
Each plate travels at different speeds and in different directions.
Collisions between plates causes stress at plate boundaries, resulting in deformation.

5. Stress and Deformation (cont.)
5.1 Interactions at Plate Boundaries
Stress and Deformation (cont.)

6. 5.1 Interactions at Plate Boundaries
Deforming Rocks
Plastic deformation occurs when rocks change shape by folding under high temperatures and pressure.
Elastic deformation occurs when rocks resume their original shapes after the stress is removed.

7. Deforming Rocks (cont.)
5.1 Interactions at Plate Boundaries
Deforming Rocks (cont.)
A fracture is a break or crack in rock.
If rock on side of a fracture has moved relative to the other side it is called a fault.

8. Types of Stress Three main types of stress:
5.1 Interactions at Plate Boundaries
Types of Stress
Three main types of stress:
Tension: rocks are stretched
Compression: rocks are squeezed
Shear: rocks slide horizontal in opposite directions

9. 5.1 Interactions at Plate Boundaries
Types of Stress (cont.)

10. Types of Faults Three main types of faults: Normal faults
5.1 Interactions at Plate Boundaries
Types of Faults
Three main types of faults:
Normal faults
Reverse faults
Strike-slip faults

11. 5.1 Interactions at Plate Boundaries
Normal Faults
Normal faults result from tension stress and slope at an angle.

12. 5.1 Interactions at Plate Boundaries
Reverse Faults
Reverse faults result from compression stress and slope at an angle.

13. 5.1 Interactions at Plate Boundaries
Strike-Slip Faults
Strike-slip faults result from shearing stress and are often vertical.

14. Types of Plate Boundaries
5.1 Interactions at Plate Boundaries
Types of Plate Boundaries
Divergent plate boundary occurs when two lithospheric plates move apart.
Convergent plate boundaries form when two lithospheric plates move toward each other.

15. Divergent Plate Boundaries
5.1 Interactions at Plate Boundaries
Divergent Plate Boundaries
Mid-ocean ridges occur along divergent plate boundaries.

16. Divergent Plate Boundaries (cont.)
5.1 Interactions at Plate Boundaries
Divergent Plate Boundaries (cont.)
Continental rifting occurs when two continental plates are being pulled apart.
East African Rift
Gulf of California

17. Convergent Plate Boundaries
5.1 Interactions at Plate Boundaries
Convergent Plate Boundaries
Three possible interactions:
Ocean-to-ocean: two oceanic plates move towards each other—subduction occurs as one plate is forced down into the mantle beneath another plate
Ocean-to-continent: oceanic plate subducts beneath continental plate
Continent-to-continent: compression stresses force crust to rise up, thicken, and shorten

18. Convergent Plate Boundaries (cont.)
5.1 Interactions at Plate Boundaries
Convergent Plate Boundaries (cont.)

19. Transform Plate Boundaries
5.1 Interactions at Plate Boundaries
Transform Plate Boundaries
A transform plate boundary exists when two plates slide horizontally past one another.

20. Transform Plate Boundaries (cont.)
5.1 Interactions at Plate Boundaries
Transform Plate Boundaries (cont.)
Oceanic transform plate boundaries connect pieces of the mid-ocean ridges.
Transform plate boundaries can slice through continental lithosphere as strike-slip faults.
Large earthquakes can occur on these faults and can be very destructive.
Where do most earthquake epicenters and volcanoes occur?

21. What type of deformation results from tension?
5.1 Interactions at Plate Boundaries A B C D
What type of deformation results from tension?
A thickening of the lithosphere
B compression of the lithosphere
C thinning of the lithosphere
D movement of rocks past each other
Lesson 1 Review

22. Subduction results from _____.
5.1 Interactions at Plate Boundaries A B C D
Subduction results from _____.
A one oceanic plate being forced into the mantle beneath another plate
B two plates moving away from each other
C two continental plates colliding with each other
D two continental plates sliding horizontally past each other
Lesson 1 Review

23. 5.1 Interactions at Plate Boundaries
What type of plate boundary separates the North American and Pacific Plates in California?
A convergent
B rift
C transform
D divergent
Lesson 1 Review

24. End of Lesson 1

25. 5.2 California Geology
San Andreas Fault

26. Plate Tectonics in California
5.2 California Geology
Plate Tectonics in California
A continental transform plate boundary cuts across California.
A convergent plate boundary resides off the northern shore of California.
This active plate tectonic setting produces earthquakes, volcanoes, and mountains.

27. 5.2 California Geology
80 Million Years Ago

28. Transform Plate Boundary
5.2 California Geology
Transform Plate Boundary
The San Andreas Fault is a transform plate boundary between the North American and Pacific Plates.
This boundary switches to an oceanic transform boundary when it goes out to sea.

29. Convergent Plate Boundaries
5.2 California Geology
Convergent Plate Boundaries
Two small oceanic plates are being subducted in the Cascadia Subduction Zone.
This subduction zone forms a convergent plate boundary.

30. California’s Mountains
5.2 California Geology
California’s Mountains
California’s mountains often formed from interactions at several plate boundaries.

31. 5.2 California Geology
Subduction
The Klamath Mountains, Costal Ranges, peninsulas, and Sierra Nevada all contain igneous and metamorphic rocks formed below the surface.
These rocks were formed when an ancient oceanic plate subducted beneath the North American Plate.

32. Rifting Some mountains in California have formed from tension stress.
5.2 California Geology
Rifting
Some mountains in California have formed from tension stress.
The Panamint Range is rising up as the crust in eastern California stretches.

33. Convergent plate boundaries in California are important in _____.
5.2 California Geology A B C D
Convergent plate boundaries in California are important in _____.
A the development of California’s rift valleys
B the formation of California’s mountains
C movement along the San Andreas Fault
D the existence of the Gulf of California
Lesson 2 Review

34. B convergent plate boundary C rift valley D strike-slip fault
5.2 California Geology A B C D
The San Andreas Fault is a transform plate boundary; this also makes it a _____.
A subduction zone
B convergent plate boundary
C rift valley
D strike-slip fault
Lesson 2 Review

35. Which of the following are active California volcanoes?
5.2 California Geology A B C D
Which of the following are active California volcanoes?
A Lassen Peak and San Andreas
B Sierra Nevada and Mount Shasta
C Lassen Peak and Mount Shasta
D Panamint Range and Mount Shasta
Lesson 2 Review

36. End of Lesson 2

37. Chapter Resources Menu
Chapter Assessment
California Standards Practice
Image Bank
Science Online
Interactive Table
Virtual Lab
Click on a hyperlink to view the corresponding feature.

38. What does shearing stress produce when plates slide past each other? B C D
What does shearing stress produce when plates slide past each other?
A subduction zones
B strike-slip faults
C divergent plate boundaries
D rift valleys
Chapter Assessment 1

39. Where do mid-ocean ridges usually occur? A convergent plate boundaries
B strike-slip faults
C divergent plate boundaries
D normal faults
Chapter Assessment 2

40. In what areas of the Earth does present-day continental rifting occur? B C D
In what areas of the Earth does present-day continental rifting occur?
A eastern Africa and western South America
B the Gulf of California and eastern South America
C Gulf of California and the Himalayas
D eastern Africa and the Gulf of California
Chapter Assessment 3

41. A San Andreas and Juan de Fuca B Juan de Fuca and Gorda
Which two oceanic plates are being subducted in the Cascadia Subduction Zone?
A San Andreas and Juan de Fuca
B Juan de Fuca and Gorda
C Gorda and San Andreas
D San Andreas and Pacific
Chapter Assessment 4

42. The San Andreas Fault is a(n) _____. A strike-slip fault B C D
The San Andreas Fault is a(n) _____.
A strike-slip fault
B oceanic transform plate boundary
C subduction zone
D rift valley
Chapter Assessment 5

43. Northern California is located _____. A above a subduction zone
SCI 1.f A B C D
Northern California is located _____.
A above a subduction zone
B below a subduction zone
C above a rift valley
D below a rift valley
CA Standards Practice 1

44. A two oceanic plates pulling apart B two continental plates colliding
SCI 1.e A B C D
Which of the following scenarios would most likely result in the development of mountains?
A two oceanic plates pulling apart
B two continental plates colliding
C one oceanic and one continental plate colliding
D erosion by wind and water
CA Standards Practice 2

45. The Pacific Plate moves about 3.4 cm/year relative to the ____.
SCI 7.g A B C D
The Pacific Plate moves about 3.4 cm/year relative to the ____.
A Atlantic Plate
B San Andreas Plate
C North American Plate
D Gorda Plate
CA Standards Practice 3

46. B the result of two plates moving away each other
SCI 1.e A B C D
What is subduction?
A the process in which one plate is forced down into the mantle beneath the other plate
B the result of two plates moving away each other
C the process of two continental plates colliding
D the result of two plates sliding sideways past each other
CA Standards Practice 4

47. Deformation that results from compression stress is _____.
SCI 1.e A B C D
Deformation that results from compression stress is _____.
A the thickening of the lithosphere
B the melting of the rocks
C the thinning of the lithosphere
D always minimal
CA Standards Practice 5

48. Image Bank

49. Interactive Table

50. End of Resources