PLATE TECTONICS

WARM-UP: The Theory of Plate Tectonics encompasses the hypotheses, ideas, and processes you researched on your timeline. With that being said: What is the Theory of Plate Tectonics? Key Question Objective What is the Theory of Plate Tectonics? What discoveries, contributions, and ideas led to its development and acceptance? Students will analyze their timelines and prior knowledge/notes to summarize the Theory of Plate Tectonics to explain its importance to geology?

What is the Theory of Plate Tectonics? The Theory of Plate Tectonics states that the Earth's outermost layer is fragmented into a dozen or more large and small plates that are moving relative to one another as they ride atop hotter, more mobile material. It explains the formation, movement, and recycling of Earth’s Crust.

From what TWO main ideas/hypotheses does Plate Tectonics pull? Continental Drift Seafloor Spreading States that all the continents were once joined together in a single landmass (Pangaea) and have since drifted/moved apart. States that the seafloor spreads apart along both sides of a mid-ocean ridge as new crust is added.

The same EVIDENCE that supports Seafloor Spreading and Continental Drift ALSO support Plate Tectonics, so… Continental Drift Evidence? Seafloor Spreading Evidence? Fossil Evidence: Identical fossils are found on continents now separated by water. The species could not have traveled by wind or water, and a land bridge is unlikely. Climate Evidence: Glacial Striations match like puzzle pieces and are found in places that are no longer cold. Tropical Fossils are found in polar regions Coal is found in places that cannot support the formation of coal any longer Geological Evidence: Coastlines fit like a puzzle Mountain Ranges along coastlines are similar in age and structure Age of the Seafloor: Samples of the deep ocean floor show that the seafloor becomes progressively younger as the mid-ocean ridge is approached, so new rock is being formed at the mid-ocean ridge. Magnetic Reversals: Since the material was molten (we know b/c it preserves the magnetic history), it proves that new material is forming. The magnetic reversals date the rocks and show that the rocks get older as we move away from the ridge, proving new rocks form. Only write down the bolded and underlined words

According to the Theory, the world is divided into tectonic plates, which are… (also called lithospheric plate) is a massive, irregularly shaped slab of solid rock, generally composed of both continental and oceanic lithosphere

CONVECTION! How do the plates move? How do the plates move?