1. Deforming the Earth’s Crust
Chapter 4 Section 3, 4
Deforming the Earth’s Crust

3. Deformed Undeformed Deformation
The process by which the shape of a rock changes because of stress
Deformed
Undeformed

4. Stress There are three types!
The amount of force per unit area on a given material
There are three types!

5. stress that occurs when an object is squeezed
Compression
stress that occurs when an object is squeezed

6. stress that occurs when an object is squeezed
Compression
stress that occurs when an object is squeezed

7. Shear
Stress that occurs when forces act parallel to the surface, pushing in opposite directions,

8. Shear
Stress that occurs when forces act parallel to the surface, pushing in opposite directions

9. stress that occurs when an object is stretched
Tension
stress that occurs when an object is stretched

10. stress that occurs when an object is stretched
Tension
stress that occurs when an object is stretched

11. Deforming the Earth’s Crust
Rock layers bend and break when stress is placed on them!

12. Look at the arrows. Which type of stress is being illustrated?
REVIEW
Tension
Compression
Stress that occurs when forces act to squeeze an object
Stress that occurs when forces act to stretch an object
Shear
Stress that occurs when forces act parallel to the surface, pushing in opposite directions, producing cutting instead of compression or tension

13. What type of stress causes folding?
REVIEW
bending of rock layers because of stress in Earth’s crust

14. Q: How do the forces of plate tectonics cause rock to deform?
COMPREHENSION CHECK!
Q: How do the forces of plate tectonics cause rock to deform? A:
Compression can cause rocks to be pushed into mountain ranges as tectonic plates collide at convergent boundaries. Tension can pull rocks apart as tectonic plates separate at divergent boundaries.

15. Q: What is plate tectonics?
CONCEPT REVIEW!
Q: What is plate tectonics? A:
Plate tectonics is the theory that explains how large pieces of the Earth’s outermost layer, called tectonic plates, move and change shape.

16. Compression Shear Tension
Compression
Shear
Tension

17. Compression Shear Tension

18. Compression Shear Tension

19. Boundary
A place where tectonic plates touch

21. Convergent Boundary Compression
The boundary formed by the collision of two lithospheric plates – Two plates come together
Compression
Hyperlink to Convergent Boundary Animation

22. Continental-Continental Boundaries
Convergent Boundary
The boundary formed by the collision of two lithospheric plates
Continental-Continental Boundaries

23. Oceanic-Oceanic Boundaries
Convergent Boundary
The boundary formed by the collision of two lithospheric plates
Oceanic-Oceanic Boundaries

24. Continental-Oceanic Boundaries
Convergent Boundary
The boundary formed by the collision of two lithospheric plates
Continental-Oceanic Boundaries

25. Subduction Zone
Where two plates meet and one slides under the other

26. Transform Boundary Shear
The boundary between tectonic plates that are sliding past each other horizontally
Shear
Hyperlink to Transform Boundary Animation

27. Transform Boundary
The boundary between tectonic plates that are sliding past each other horizontally
Hyperlink to Video 3:03
San Andreas Fault
California, USA

28. Divergent Boundary Tension
The boundary between two tectonic plates that are moving away from each other, or separate
Tension
Hyperlink to Divergent Boundary Animation

29. Divergent Boundary
The boundary between two tectonic plates that are moving away from each other
Hyperlink to Divergent Boundary 0:11

30. Mid-Ocean Ridge
A long, undersea mountain chain that forms along the floor of the major oceans 

31. Mid-Ocean Ridge
A long, undersea mountain chain that forms along the floor of the major oceans 

32. Fault
A break in a body of rock along which one block slides relative to another 

33. Fault
A break in a body of rock along which one block slides relative to another 

34. The blocks of crust on each side of a fault are called “fault blocks”.

35. The blocks of crust on each side of a fault are called “fault blocks”.

36. Hanging Wall Footwall

37. Reverse Fault Based on the GRAPHIC ORGANIZER,
what type of deformation causes reverse faults?

38. Reverse Fault Based on the GRAPHIC ORGANIZER,
what type of boundary is a reverse fault?

39. Reverse Fault The hanging wall moves up relative to the footwall.
These normally occur when tectonic forces cause compression
that pushes rocks together.
Hyperlink to Animation of Reverse Fault

40. Strike-Slip Fault Based on the GRAPHIC ORGANIZER,
what type of deformation causes strike slip faults?

41. Strike-Slip Fault Based on the GRAPHIC ORGANIZER,
what type of boundary is a strike slip fault?

42. Strike-Slip Fault
These faults form when opposing forces cause rock to break and move horizontally.
Hyperlink to Animation of Strike-Slip Fault

43. Normal Fault Based on the GRAPHIC ORGANIZER,
what type of deformation causes normal faults?

44. Normal Fault Based on the GRAPHIC ORGANIZER,
what type of boundary is a normal fault?

45. Normal Fault The hanging wall moves down relative to the footwall.
Hyperlink to Animation of Normal Fault

46. Rift Zone
A set of deep cracks that forms between two plates that are pulling away from each other
The East African Rift is an active continental rift zone in eastern Africa. The rift is a narrow zone in which the African Plate is in the process of splitting into two new tectonic plates called the Somali Plate and the Nubian Plate, which are sub plates or protoplates.
The actual rift between the North American tectonic plate and the Eurasian plate. Iceland is the only place where this is visible above water.

47. Rift Zone
A set of deep cracks that forms between two plates that are pulling away from each other
Southwest Rift, Hawaii
The rift was formed over time during eruption of Kilauea. Hot magma moved underground from the summit reservoir in to the rift zone and tore the crust apart.

48. Rift Zone
A set of deep cracks that forms between two plates that are pulling away from each other
Southwest Rift
Hawaii

50. A B Reverse Normal Strike-Slip C
Name each type of Fault A B
Reverse
Normal
Strike-Slip C

51. What type of fault is this?
Strike-Slip

52. COMPREHENSION CHECK!
Q: How does the hanging wall in a normal fault move in relation to a reverse fault? A:
In a normal fault, the hanging wall moves DOWN.
In a reverse fault, the hanging wall moves UP.

53. When Plates Collide
Land features that start as folds and faults can eventually become large mountain ranges.
Mountains exist because tectonic plates are continually moving around and colliding with one another.

54. Uplift M O V E ME N T V E R T I C A L
rising of regions of Earth’s crust to higher elevations
V E R T I C A L M O V E ME N T

55. Subsidence M O V E ME N T V E R T I C A L
the sinking of Earth’s crust to lower elevations
V E R T I C A L M O V E ME N T

56. the sinking of Earth’s crust to lower elevations
V E R T I C A L
Subsidence
the sinking of Earth’s crust to lower elevations M O V E ME N T

57. http://www. windows2universe

58. Q: How do uplift and subsidence differ?
COMPREHENSION CHECK!
Q: How do uplift and subsidence differ?
A: Uplift is the rising of the Earth’s crust to higher elevations. Subsidence is the sinking of the Earth’s crust to lower elevations.

59. Q: What are rift zones? How do they form?
COMPREHENSION CHECK!
Q: What are rift zones? How do they form?
A: Rift zones are cracks that form where two plates are pulling away from each other. As they pull apart, stress builds and faults form along the rift zone.