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25 Cards in this Set
- Front
- Back
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Who is Alfred Wegener?
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German meteorologist, came up with Pangaea.
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Pangaea
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all the continents fit together.
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Gondwanaland
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found by Edward Suess, large supercontinent that implied had existed, bottom of pangaea
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Lautsia
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top of pangaea
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Evidence for Continental Drift
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-match of Continental outlines -continuity of moutain belts and other geological formations across continent boundries -similar fossils of separate continents -glacial deposits and other paleoclimate indicators inconsistent with current continent location
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What kind of fossils were found for evidence of continental drift?
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Fossils of the upper paleozoic fern glossopteris
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why was his idea rejected?
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the fit was not perfect, the correlation of rock units was weak, the tillites were not glacial deposits, the northern hemisphere coals were not tropical, errors int the calculated motion of Greenland presented by Wegener
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Crust
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the outer skin, very thin, divided into oceanic and continental crust, 25-70 miles thick
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mantle
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thickest layer, solid, asthenosphere
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Core
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iron-nickel alloy, divided into the inner and outer core, the outer core is liquid which generates the Eath's magnetic field, the inner core behaves like a solid due to the increased pressure
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Evidence of plate tectonics
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paleomagnetism, magnetic reversals, earthquake and Volcano Distribution Pattern
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Magnetic Reversals
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Zebra stripped pattern of normal and reversed polarity in ocean floor, parallel to the ocean ridge, both sides of the ridge are of equal size and polarity, material furthest away is older in age, gave rise to sea-floor spreading
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Earthquake and Volcano Distribution Pattern
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deep earthquakes were shown to be inland a little from the trenches while shallow earthquakes were near the trenches. Volcanoes formed closer to the deep earthquakes.
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Paleomagnetism
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magnetite of Greenland basalts were not pointing to the present poles
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Lithospheric Plates
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Eurasian, indo-Australian, Pacific (ring of fire), North American, South American, Antarctic, African,
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Divergent Plate Boundries
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moving apart, can produce a rift valley, produce earthquakes and rifts Ex:african rift valleys
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Convergent
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come together in a collision, oceanic crust-oceanic, oceanic-continental, continental-continental produce volcanoes Ex:Japan
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Transform
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plates grind past each other Ex: San Andreas Fault of California
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Subduction
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oceanic crust subducts under another crust and along rifts, deep ocean trenches develop
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Hot Spot
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like a blow torch within the mantle which melts through the crust, plate is moving so teh older volcanoes are no longer active b/c plate is not over hot spot
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Convection
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mechanism for plate movement
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What is a Volcanoes
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a weak spot in the crust where magma comes to the surface
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What is a volcano made of
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magma, a molten mixture of rock forming substances, gases, and water vapor
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magma on the surface is called
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lava
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Where are volcanos found?
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ring of fire
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