10.4 - 10.6 Notes Flashcards
plate movement is caused by
convection currents pulling and pushing the crust
where two plates are moving apart
divergent boundaries
large areas where the crust has fractured and created depressions with steep walls common feature of a divergent boundary
rift valleys
mountainous ranges where magma reaches the surface
oceanic ridges
seafloor spreading produces
new crust
where two plates grind past each other
transform boundaries
plates are ____ to the direction of plate movement in transform boundaries
parallel
what do transform boundaries usually join
two segments of a mid-ocean ridge
where two plates are moving together
convergent boundaries
occurs when one plate moves under the other
subduction zone
denser oceanic crust ___ into the asthenosphere
sink
what develops and rises on the oceanic-continental boundary
pockets of magma
what forms by the subduction of oceanic lithosphere beneath a continent
continental volcanoes
when two oceanic plates converge and one descends beneath the other
oceanic-oceanic boundary
an oceanic-oceanic boundary forms what
volcanoes on the ocean floor
what forms as a volcano emerges from the sea
volcanic islands
when two continental plates collide and one plate subducts under the other
continental-continental boundary
what does continental-continental boundary produce
mountain ranges such as the Himalayas
zones of the ocean floor that separates the thin oceanic crust from the thick continental crust
continental margin
large flat sediment covered area of the ocean floor
abyssal plain
underwater mountain system formed by divergent plates - creates new crust
mid ocean ridge
as plates move apart faults are created. Sections of crust can drop down creating depressions
rift valley
a long narrow steep sided depression caused by a subduction zone
trench
a submarine mountain that creates an island when it reaches the surface of the ocean
seamount/island
