1. Plate Tectonics The theory of plate movement and the dynamic crust

2. Plate Tectonic Theory
Earth’s crust is broken up into plates. The plates can be oceanic basalt or continental granite rock
The plates are pushed around by convection cells in the asthenosphere (upper mantle)
The plates converge and diverge at plate boundaries creating various features!

3. ESRTs Page 5

4. Plate Tectonics Evidence
Sea floor spreading shows that the plates move around. Evidence for it includes…
Ocean floor crust gets older as distance from the mid ocean ridge increases
Ocean floor rock magnetic reversals
Ocean floor crust temperature decreases as distance from mid ocean ridge increases

5. Plate Tectonics Evidence
Crustal activity mainly at plate boundaries!
Crustal change: uplift, faulting, folding
Earthquakes
Volcanoes form where rock melts
The Pacific “RING OF FIRE” shows this better than anywhere!
Ring of Fire Map

6. Plate Tectonics Evidence
Earthquakes and Volcanoes around the Pacific

7. Plate Tectonics Evidence
Earthquakes and Volcanoes around the Pacific

8. Plate Tectonics Evidence
Continental Drift…which is proven by
How continents appear to fit together like “puzzle pieces”
The same rocks and fossils found on Africa and South America
Coal found in North America, which could only have formed in a tropical climate

9. Pangaea: “super continent” 230mya
Plate Tectonics Evidence
Pangaea: “super continent” 230mya

10. A B D C
ESRTs Page 5