1. Continental Drift and Plate Tectonics (notes pt. 2)

2. 2.55 g/cm3 x 4.5 g/cm3 x
11.05 g/cm3 x
12.95 g/cm3

3. Plate Boundary types:
Transform Boundary - Place where two plates meet and slide past each other. Also known as a sliding boundary. Example: San Andreas Fault

4. Plate Boundary types:
Transform Boundary - Place where two plates meet and slide past each other. Transform boundaries are conservative as crust is neither created nor destroyed at them.

5. Plate Boundary types:
Divergent Boundary – Where two plates are moving away from each other.
Examples: mid-ocean ridges where new sea crust forms, rift valleys on land.

6. Plate Boundary types:
Divergent boundaries occur along spreading centers where plates are moving apart.
Two diverging oceanic plates produce sea-floor spreading and new crust formation at the boundary. They are constructive.

7. Diverging oceanic plates:
Mid-Atlantic Ridge:

8. Diverging plates - (what type?)
Iceland:

9. Plate Boundary types:
Two diverging continental plates can produce surface cracking and volcanic activity.
As the plates stretch, cracks appear that fill with magma, pushing the rift even wider.

10. Diverging continental plates:
East Africa:

11. Rift valleys:
Divergent boundaries are constructive as new crust is created at them.

12. Plate Tectonics (notes pt. 3)

13. Plate Boundary types: 
Convergent boundaries occur where two plates are moving toward each other. 
melting
Where one plate sinks below another it is called a subduction zone.

14. Plate Boundary types:
Oceanic crust subducting under continental crust can form continental volcanic arcs.
The more dense oceanic crust melts once it descends deep enough into the mantle.

15. Converging Boundaries:
Boundaries are destructive as crust is being lost. Ocean/Cont. Examples: Cascades, Andes volcanoes.

16. Plate Boundary types:
Oceanic crust subducting under other oceanic crust can form volcanic island arcs.
The older, more dense oceanic crust melts once it enters the mantle.

17. Converging Boundaries:
Ocean / Ocean Examples: Aleutian Islands, Mariana Islands.

18. When two continental plates converge, neither is dense enough to subduct. 
Since neither plate sinks, they push into one another and mountain forming happens.

19. Convergent Boundaries:
Cont. / Cont. example: Indian plate meeting Eurasian plate

20. Plate irregularities:
Hot spot: A volcanic area that forms as a tectonic plate moves over a point heated from deep within the Earth's mantle.

21. Plate irregularities :
Accretion: as a continental volcanic arc forms the subducting plate has sediments and chunks scraped off that accumulate on the continental plate

22. Accretionary wedge
Example: the west
coast of North America