1. Plate Boundaries, Faults, and Stress Unit 2 Lesson 2

2. Lithosphere - Asthenosphere - rigid, brittle crust and uppermost part of mantle Oceanic crust – thin, dense, basalt Continental crust – thick, low density, granite partially molten part of upper mantle, able to flow

4. Plate Boundaries TransformConvergentDivergent plates move toward each other and collide; crust is destroyed & one plate is pushed below the other plates slide horizontally past each other; crust is neither produced or destroyed plates move away from each other; new crust is generated between the separating plates

5. Convergent Plate Boundary Continent to Continent Subduction Form mountain belts Oceanic crust dives below either oceanic or continental crust Form deep-sea trench Ocean-continent – volcanic mountains along edge Ocean-ocean – volcanic island arc

6. Convergent Plate Boundary Subduction Zones

7. Faults  Fractures (breaks) in the earth occur when a force is applied to the underlying rock, which movement occurs.  Stress is the force per unit area acting upon a material.  There are 3 types of stress that acts upon the Earth’s rocks:  Compression: decreases material volume (shorten)  Tension: pulls the material apart (lengthen)  Shear: Causes the material to slip or twist (distortion)

8. Types of Faults  Slip Faults  Horizontal tension  Sideways movement  Normal Fault  Tension (Apart)  Down on advancing block  Thrust/Reverse Fault  Compression  Uplift of advancing block

9. Examples of Faults  Reverse Fault  Note the compression  Note the uplift  San Andreas Fault  Pulled apart  Sideways movement

10. Fault Summary…  http://youtu.be/lyfND_lugSo http://youtu.be/lyfND_lugSo