1. By: Anthony Perkins

2. The Pangaea Theory Pangaea was a supposed supercontinent made up of all our current continents. Alfred Wegener - In 1912 he came up with the theory Of Pangaea. The name means “all lands.” -He said Pangaea was probably intact Until late Carboniferous period. http://www.ucmp.berkeley.edu/geology/tec hist.html

3. - other than geology he was accomplished in Astronomy, Meteorology and Climatology. These all helped him to come up with his theory/discovery. When Wegener first proposed the idea it was dismissed. - He could not provide an adequate explanation of the forces responsible for continental drift or disprove the theory that Earth was solid and immovable. http://www.ucmp.berkeley.edu/geology/tec hist.html

4. Arthur Holmes - His ideas later assisted in the recognition of Wegener’s theory. - He elaborated on Wegener’s hypothesis. He said that thermal convection affects the mantle. It causes it to heat and cool. Heating and cooling over a period of time can cause a continent to split up and move. - This received little attention at the time it was proposed. http://www.ucmp.berkeley.edu/geology/tec hist.html

5. The theory being discussed at this time was the Contraction theory. - This said that the Earth was once a molten ball and the act of cooling caused some parts of the Earth to fold in on itself. http://www.ucmp.berkeley.edu/geology/tec hist.html

6. Convergent Boundaries Convergent Boundary: A boundary were one plate overrides another one and forces it under. The one pushed under becomes part of the mantle again. Mountain What it causes: - Mountains - Earthquakes - Volcanoes - Trenches http://scign.jpl.nasa.gov/learn/plate4.htm Plate: A piece of the broken up lithosphere that floats on the asthenosphere. (top part of Earth.) Boundary: Where two plates meet.

7. One example of a Convergent Boundary is the Ring of Fire. - A ring of volcanoes around the edges of the Pacific Plate. - due precisely to there being a lot of convergent zones around there. Volcano http://scign.jpl.nasa.gov/learn/plate4.htm

8. Pictures!!! Convergent Boundary Mariana Trench

9. Divergent Boundaries Divergent Boundary: At a Divergent Boundary two plates move away from each other. As the plates move away from each other mid- ocean ridges are formed because magma forces itself up through the cracks and cools. Mid-Ocean Trench What it causes: - Mid-Ocean Ridges http://scign.jpl.nasa.gov/learn/plate4.htm

10. One example of a Divergent Boundary is