Plate Tectonics The theory of plate movement and the dynamic crust

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!

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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

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

Plate Tectonics Evidence Earthquakes and Volcanoes around the Pacific

Plate Tectonics Evidence Earthquakes and Volcanoes around the Pacific

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

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

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