1. Plate Tectonics The Earth’s Crust in Motion…

2. The Theory In 1910 Alfred begins to wonder… What’s the relationship? Perhaps all these pieces used to be connected. Continental drift=slow movement over Earth’s surface 300 million years ago…

3. Supercontinent Pangea – all lands Reptiles and insects Tropical forrests -coal deposits  Tens of Millions of years!

4. Structure of the Earth’s Interior

5. How does it work? Plates – pieces of the lithosphere Plates fit closely together along cracks called Plate Boundaries Convection Currents  movement

6. Earth’s Puzzle What plate do we live on? What plates do we border? USGS Earth’s Plates How far do we move every year?

7. Types of Boundaries Divergent Convergent Transform

8. A Divergent B Convergent C Transform plates are moving apart new crust is created Magma is coming to the surface plates are coming together crust is returning to the mantle plates are slipping past each other crust is not created or destroyed

9. A Divergent B Convergent C Transform Continental crust  rift valley Oceanic crust  mid- ocean ridge 2 continental plates  mountain range Plates move against each other Stress builds up Stress is released  earthquake 2 oceanic plates or oceanic + continental  subduction

10. The Big Picture

11. Key Terms convergent boundary divergent boundary transform boundary subduction rift valley mid-ocean ridge continental crust oceanic crust mountain range earthquake