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Plate Tectonics
Ch. 3; Section 3, 4, 5
Term | Definition |
---|---|
continental drift | hypothesis that the continents were once all joined together in a single landmass and have since drifted apart. |
Pangaea | supercontinent formed when all the continents were joined together |
fossil | any trace of an ancient organism preserved in rock |
mid-ocean ridge | a system of underwater mountain systems that wind beneath Eart's oceans |
sonar | a device that bounces sound waves off underwater objects and then records the echoes to determine distance of the object |
sea-floor spreading | theory that the sea floor spreads apart along both sides of the mid-ocean ridge as new crust is added |
deep-cean trench | canyon where the oceanic crust bends downward |
subduction | the process by which ocean floor sinks beneath a deep-ocean trench and back into the mantle |
plates | sections that the lithospheric plate is broken into |
scientific theory | well-tested concept that explains a wide range of observations |
plate tectonics | theory that explains the formation, movement, and subduction of Earth's plates |
faults | breaks in Earth's crust where rocks have slipped past each other |
divergent boundary | place where two plates move apart |
rift valley | deep valley that forms along a divergent boundary |
convergent boundary | place where two plates come together in a collision |
transform boundary | place where two plates slip past each other, moving in opposite directions |