Term
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Definition
| hypothesis of continental drift |
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Term
| evidence for continental drift |
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Definition
continents fit together
fossils match across the seas
rock types & structures match
ancient climates |
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Term
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Definition
| supercontinent broke into smaller pieces & drifted apart |
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Term
| reason for rejecting Wegener |
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Definition
didn't provide way to move continents
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Term
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Definition
| proposed seafloor spreading |
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Term
| evidence for seafloor spreading |
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Definition
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Term
| evidence for plate tectonics |
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Definition
polar wandering
guyots
magnetic stripes on the sea floor |
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Term
| Vine , Matthews, and Morley |
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Definition
Magnetic anomalies resulted ffromt he interaction of
seafloor spreading
reversals of the earth's magnetic field |
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Term
| driving force for plate movement |
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Definition
convection currents
slab-push (ridge)
slab-pull (trench)
mantle plumes |
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Term
| divergent plate boundaries |
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Definition
spreading centers where new crust is created
volcanic activity basalitc
earthquakes = shallow focus
crust older further away |
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Term
| convergent plate boundaries |
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Definition
correspond to subduction zones in seafloor spreading model
shallow to deep focus
magmatic arcs forming volcanic islands |
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Term
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Definition
trench
volcanoes
back-arc basin |
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Term
| ocean-continent convergent |
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Definition
magmas form batholiths
heat causes regional and contact metamorphism
magma is andesitic to rhyolitic
stratovolcanoes on continental crust
melange - accretionary wedge |
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Term
| continent-continent convergent |
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Definition
neither continent subducts: collision
orogenesis: crustal thickening and deformation
suture between 2 cont: melange and ophiolite |
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Term
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Definition
columns of hot material rising through mantle
source: core-mantle boundary |
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Term
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Definition
convergent boundaries
sites where lithosphere is descending into the asthenosphre
occurs because the density of the descending lithospheric plate is greater than that of the underlying asthenosphere |
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Term
| reasons for plate spreading |
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Definition
convection cells in the mantle
ridge/slab push
trench/slab pull
hot plumes |
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Term
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Definition
natural magnetism in rock bodies
used to determine the location of the magnetic poles and the latitude of the rock at the time it became magnetized |
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Term
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Definition
| earth's magnetic field has reversed itself globally |
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