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16 Cards in this Set

  • Front
  • Back
continental drift
Wegener's hypothesis that all continents were once connected in a single, large landmass
large, ancient landmass that was composed of all the continents joined together
sea floor spreading
Hess's theory that new seafloor is formed when magma is forced upward toward the surface at a mid-ocean ridge
plate tectonics
theory that Earth's crust and upper mantle are broken into plates that float and move around
a large section of Earth's oceanic or continental crust and rigid upper mantle that moves around on the asthenosphere
rigid layer of Earth about 100 km thick, made of the crust and a part of the upper mantle
plasticlike layer of Earth on which the lithospheric plates float and move around
convection current
convection deals with heat
current in Earth's mantle that transfers heat in Earth's interior and is the driving force for plate tectonics
Alfred Wegener
Wegener's idea
of continental drift
mapping of the ocean floor in the 1950s showed
underwater mountains and rift valleys
Harry Hess
suggested seafloor spreading
How is magnetic evidence preserved in rocks forming along a mid-ocean ridge
do you know this?
magnetic evidence
theory of seafloor spreading is supported by magnetic evidence in rocks
convection currents
move plates
How do converging plates form mountains?
converge means come together, they overlap and form mountains

diverge means split apart (trench)