Science Chapter 4

Front 1

continental drift hypothesis

Back 1

states continents had moved

Front 2

pangaea

Back 2

continents once formed part of a land mass called pangea ( all lands)

Front 3

panthalassa

Back 3

surrounded seas of pangea meaning (all seas)

Front 4

mid atlantic ridge

Back 4

an undersea mountain range with a steep narrow valley running down its center

Front 5

mid ocean ridges

Back 5

mid atlantic ridge is apart of an entire system of mid ocean ridges. 65000 km long that wind their way around the earth

Front 6

seafloor spreading

Back 6

valley at center of ridge was actually a break or rift in earth crust and molten rock from deep inside the earth was welling up through the rift

Front 7

plate tectonic theory

Back 7

hypothesis of continental drift and seafloor spreading

Front 8

oceanic crust

Back 8

ocean forms oceanic crust

Front 9

continental crust

Back 9

continental crust make of continental landmass

Front 10

lithosphere

Back 10

oceanic and continental crust and the rigid upper mantle make up the lithosphere

Front 11

asthenosphere

Back 11

beneath the lithosphere, solid rock that flows.

Front 12

convergent boundary

Back 12

the direct collision of one plate with another

Front 13

subduction zone

Back 13

plate boundarys where one plate boundary moves under another plate as a subduction zone

Front 14

ocean trench

Back 14

forms along a subduction zone. as the oceanic plate moves down into subduction zone, it melts and becomes part of mantle material

Front 15

transform fault boundary

Back 15

forms where two plate are grinding past each other

Front 16

convection current

Back 16

warm water rising and cool water sinking to replace it

Front 17

theory of suspect terranes

Back 17

theory suggests that the continents are actually pathworks of terranes

Front 18

terranes

Back 18

pieces of lithosphere