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8 Cards in this Set
- Front
- Back
continental drift |
Wegener's hypothesis that all continents were once connected in a single large landmass that broke apart about 200 million years ago and drifted slowly to their current positions. |
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Pangaea |
large, ancient landmass that was composed of all the continents joined together. |
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asthenosphere |
plasticlike layer of Earth on which the lithospheric plates float and move around |
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convection current |
current in Earth's mantle that transfers heat in Earth's interior and is the driving force for plate tectonics |
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seafloor spreading |
Hess's theory that new seafloor is formed when magma is forced upward toward the surface at a mid-ocean ridge. |
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plate tectonics |
theory that Earth's crust and upper mantle are broken into plates that float and move around on a plasticlike layer of the mantle. |
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plate |
a large section of Earth's oceanic or continental crust and rigid, upper mantle that moves around on the asthenosphere. |
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lithosphere |
rigid layer of Earth about 100 km thick, made of the crust and a part of the upper mantle. |