1. Structure of a Continent Figure 13-3

5. How are continental plates formed? Figure 13-4

8. Why was St. Louis under water during the Cambrian/Ordovician (when the fossils we saw on the field trip formed)? What can cause the ocean level to rise, relative to the land?

9. Other continents were as well

10. What happens if the plate motions are faster?

11. The plates had been moving fast – the ocean seafloor was higher on average, and ocean water spilled up onto continents.

14. Continent-Ocean Collision

16. Ocean-Ocean Collision

17. Antilles Arc

18. Subduction Zone Jump

19. Granite plutons begin deep within an orogenic belt. How do they get to the surface?

20. Granite plutons begin deep within an orogenic belt. How do they get to the surface? Erosion and Isostatic Rebound!

21. Tectonic history of North America: Growth of the Appalachians

22. Geometry of the Pacific – North America plates

23. Western Terranes

24. Western Terranes: The Rockies

25. But subduction is much more shallow than this picture shows!

27. Where does heating come from? Western Terranes: Basin and Range

32. Canadian Rockies Appalachians Alps

33. Volcanism adds rock to continental volume.

34. Hotspot volcanism often begins with a large basaltic flood.

35. Columbia flood basalts

36. Columbia flood basalts: Beginning of Yellowstone hotspot

37. Figure 13.23A

38. Figure 13.23B

39. Iguazu River Falls (Argentina)

43. Shape of Atlantic Ocean determined by Iceland hotspot

44. Afar hotspot