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27 Cards in this Set
- Front
- Back
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continental drift
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1912 alfred wegener stated that the continents move
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pangae
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wegener named the continents that formed the single landmass pangae which means all lands
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panthalassa
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surrounding pangae was the ocean which ment all seas
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mesorsaurus
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small extinct land reptile that live 270 million years ago which had been found in eastern south america and western africa
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mid atlantic ridge
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an undersea mountain range with a steep narrow valley running down the center that scientists mapped out in 1947
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mid ocean ridges
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65000 km long that goes around the earth
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sea floor spreading
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named after dietz, when the continents moved away from both sides of the ridge
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plate tectonics
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describes continental movement but also proposes a possible explanation of why and how continents move
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tectonics
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comes from greek word meaning tektonikos, which means construction, study of the formation of features in the earths crust
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oceanic crust
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material on the ocean floor
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continental crust
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makes up the continental landmass
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lithosphere
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made up by the oceanic and continental crust
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asthenosphere
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a later of plastic rock, it is solid but flows like "putty" when underpressure
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divergent boundry
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two plates that move away from eachother. found on the ocean floor. and they follow the mid ocean ridges
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rift valley
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center of the mid ocean ridge that is a narrow valley which forms as the plates separate.
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convergent boundary
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direct collision of one plate with another makes another type of plate boundry
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subduction zone
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refers to the place along a plate boundary where one plate moves under another plate
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ocean trench
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forms along a subduction zone.
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subducted
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forced under the less dense continental crust
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island arc
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part of the subducted plate melts and the molten rock rises to the surface along the trench to form a chain of volcanic islands
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transfom fault boundary
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two plates are grinding past eachother
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convection
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the transfer of heat through the movement of heated fluid material
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convection current
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the cycle of warm water rising and cool water sinking to replace it
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theory of suspect terranes
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suggests that continents are actually a patchwork of terranes which has its own distinct geological history.
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terranes
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pieces of lithosphere
1. contains rock and fossils that differ from neighboring terranes 2. major faults at the boundaries of terranes 3. magnetic properties of a terrane do not match those of neighboring terrans |
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normal polarity
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magnetic minerals in newely formed rock orients towards magnetic north
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reversed polarity
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magnetic minerals in newly formed rock orient to magnetic south
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