1. 8.2Types of plate boundaries
Explain how each type of boundary moves.
How are the 3 kinds of convergent boundaries different?
Objectives:

2. Types of plate boundaries
3 main types
Divergent
Convergent
Transform

3. Divergent boundaries
Divergent boundary (aka spreading center): a boundary between 2 lithospheric plates that are moving apart

4. Divergent boundaries Cont’d
Most are in the ocean Have rift valleys deep valleys at the center of a mid-ocean ridge Molten rock forces its way up through cracks (rifts) Older crust is pushed away from the mid-ocean ridge

5. Divergent boundaries Cont’d
Fracture zones: broken segments in the lithosphere that are perpendicular to the ridge

6. Convergent boundaries
A boundary between 2 plates that are moving toward each other Subduction boundary Collision boundary

7. Subduction boundaries
Subduct: when the denser plate moves under another plate Subduction boundary: boundary between 2 plates where one plate is pulled beneath another Deep-Sea Trench: forms along this boundary when 2 oceanic plates converge Deepest part of the ocean has a chain of volcanic islands (volcanic island arc) on the upper plate

8. Subduction boundaries Cont’d
When oceanic and continental plates converge, the denser oceanic plate is subducted A deep-sea trench is formed Mountain chain and volcanoes form on the upper continental plate

9. Collision boundaries
If 2 converging plates have continents then they may be pushed together to make a larger continent Collision boundary Causes the Earth’s crust to move upward to form mountains

10. Transform Boundaries
A boundary between 2 plates that are sliding past each other Does not move at the same rate San Andreas Fault .com/watch?v=ZxP TLmg0ZCw&spfrel oad=10 .com/watch?v=hq R2_sHDfvs

11. 8.2 Exit Ticket
Answer the following questions. Use complete sentences. You may NOT use your book. You MAY use your notes. This is a quiz grade.
Explain how each type of boundary moves.
How are the 3 kinds of convergent boundaries different?