1. Lecture 23 The earth was made so various, That the mind of desultory man, studious of change And pleased with novelty, might be indulged - Wm. Cowper (The Task, 1785) Plate Tectonics Webpage for course (daytime) Webpage for course (nighttime)

2. Alfred Wegner Meteorologist “Doesn't the east coast of South America fit exactly against the west coast of Africa, as if they had once been joined?” (1910, letter to his fiancee)

3. http://www.jazclass.aust.com/blog/files/drift.htm

4. http://geology.com/pangea.htm

5. Why was Wegner’s ideas not accepted?

6. Acceptance of Wegner’s theory Early 1960s Sea Floor spreading Subduction

7. Tests for Wegner’s theory Sea Floor spreading Age of igneous bedrock Subduction Benioff zones

8. Glomar Challenger Deep Sea Drilling Project, 1968-83 JOIDES Resolution Ocean Drilling Program, 1985-2006 refurbished and back at sea, early 2009 Deep Sea Drilling

12. “continental drift” vs. “plate tectonics

13. Plates Continental crust thicker (~50 km) older less dense Oceanic crust thinner (~10 km) younger than 200 myr more dense Mix (ex. North American Plate)

15. Margins Divergent Convergent Transverse

17. Divergent boundary, Atlantic Oc.

20. Kevin-drawing, Convergent, Pac.

21. Convergent, continent-continent

23. transverse

25. California