Plate tectonics

1
Plate tectonics

• A Layered Earth

2
Classifying the layers by composition

• Crust
• Oceanic crust
• Continental crust
• Mantle
• Core

3
Classifying the layers by physical properties

• Lithosphere
• Asthenosphere
• Mantle
• Core

4

• Isostatic equilibrium
• buoyancy
• Source of Internal heat
• Radioactive decay
• Conduction
• convection

5
The Evidence for layering

• Earth quakes
• Primary and secondary seismic waves
• Shadow zones

6

• Continental Drift
• Pangaea
• panthalassa

7

• Seafloor spreading
• Subduction zones
• Plate tectonics

8
Plate Boundaries

• Divergent plate boundaries
• mid Atlantic ridge
• Convergent plate boundaries
• Transform plate boundaries

9
Divergent plate boundaries

• Ocean Ocean
• Continent - Continent

10
Convergent plate boundaries

• Ocean Ocean
• Island arc
• Ocean Continent
• Continent - Continent

11
Confirmation of Plate Tectonics

• Paleomagnetism
• Apparent Polar wandering
• Hot spots
• Atolls and Guyots
• Age and distribution of sediments
• Terranes