1. Plate Tectonics Wrap-Up
Fit of the Continents

2. Paleoclimate & Glaciers
Ancient climatic zones and large glaciated areas match up.

3. Fossil Record

4. Glossopteris Fossils
These seeds are very large and do not float in water, so how could they have survived transport to all these different continents?

5. Ancient mountain chains match up.

6. Bathymetry

7. Magnetic Anomalies in Seafloor

8. Earthquakes

9. Volcanoes

10. Lithospheric Plates
Fig 4.3

11. The Theory of Plate Tectonics
The continents are riding along on tectonic plates, which move across the Earth’s surface driven by mantle convection (the very slow “boiling” of the mantle beneath the crust).

12. Three types of plate boundaries
Divergent – plates are moving apart from one another.
Ex: Mid-Ocean Ridges
Convergent – plates are colliding with one another.
Ex: Nazca plate and South American plate pushing up the Andes.
Ex: Indian plate and Asian plate colliding to form the Himalayas
Transform – plates are sliding past one another
Ex: Pacific plate and North American plate moving past one another along the San Andreas Fault

13. Divergent boundaries
Hot mantle material rises up and causes the crust to thin and move apart.
Mainly found in the middle of oceans
shallow, weak earthquakes
very few volcanoes
high topography on the sea floor
the youngest sea floor crust

14. Mid-Atlantic Rift in Iceland

15. Convergent boundaries
Deep trench on ocean side and then high elevations toward continent.
Shallow to deep earthquakes as you move toward continent.
Arc of volcanoes on the continent side.
No age relationship

16. Convergent boundaries
Ocean crust always moves below continental crust because ocean rocks (basalts) are more dense than continental rocks (granites).

18. Transform Boundaries
Lots of shallow earthquakes (some very strong) dispersed along the boundary.
San Andreas Fault