Plate Tectonics Flashcards
Core
dense mass of solid nickel, iron, and radioactive elements that release massive amount of heat
Mantle
liquid layer of magma surrounding core, kept liquefied by intense heat from core
convection
shifts and moves the rocky plates under Earth
asthenosphere
solid, flexible outer layer of the mantle, beneath the lithosphere
lithosphere
thin, brittle layer of rock floating on top of mantle
crust
very outer layer of the lithosphere, earth’s surface
divergent boundary
plates move away from each other
Oceanic-oceanic divergent boundary (OOD)
as plates made up of oceanic crust pull apart, a crack in the ocean floor appears, then magma oozes up from the mantle to fill in the space
what does ocean-ocean divergent boundary make?
mid-ocean ridge
continental-continental divergent boundary (CCD)
2 continental lithosphere plates diverge and a valley like rift opens
what does continental-continental divergent boundary make?
rift valleys - caused by sea floor spreading
Convergent boundary
boundaries that converge into each other
oceanic-continental convergent boundary (OCC)
the thinner and denser oceanic plate is overridden by the thicker and less dense continental plate - ocean plate undergoes subduction
subduction zones
where an oceanic plate can slide underneath a continental plate due to it’s higher density, volcanic arc grows above the subducting plate
what can oceanic-continental convergent boundaries make?
volcanoes, mountains
oceanic-oceanic convergent boundary (OOC)
one of the plates subducts under the other, the older, denser one. subducting plate is heated as it is forced deeper into the mantle and begins to melt. As magma chambers begin to rise, if they reach the surface a volcanic eruption occurs
what does oceanic-oceanic convergent boundary make?
volcanoes
continental-continental convergent boundary (CCC)
2 thick continental plates collide-no subduction, intense compression can cause extensive folding and faulting of rocks.
what do continental-continental convergent boundaries make?
mountains
transform boundary
two plates that slide past each other, sometimes they get stuck, as they unstick, energy radiates outwards and shakes the earth
example of OOD boundary
mid-atlantic ridge
what do transform boundaries make?
earthquakes
example of CCD boundary
East African rift valley, red sea
example of OCC boundary
Juan de Fuca, Andes Mountain range
example of OOC boundary
Caribbean islands of Martinique
example of CCC boundary
Himalayas
