| A | B |
|---|
| continental margin | submerged outer edge of a continent - an extension of the continent, mostly granite |
| ocean basin | deep sea floor beyond continental margin, mostly basalt |
| continental shelf | shallow submerged edge of the continent |
| continental edge | abrupt drop - off from continental shelf to continental slope |
| continental slope | steep, cliff-type area where continental shelf drops off to ocean basin |
| continental rise | thick accumulation of sediment at the base of the continental slope cliff |
| submarine canyon | deep chasm eroded into the continental shelf and slope by avalanche of water and debris |
| mid-ocean ridge | broad, low mountain range of young basalt rock located at divergent boundary where sea floor spreading occurs |
| hydrothermal vent | superheated water containing dissolved minerals and gases escapes through fissures at mid-ocean ridge |
| abyssal plains | broad, flat areas of sediment covered ocean floor found between continental margins and mid-ocean ridges |
| sea mount | volcanoes that rise from the sea floor, but do not stick up above sea level |
| guyot | flat-topped sea mount |
| oceanic trench | deepest valleys that occur at subduction zones where plates converge |
| island arcs | lines of volcanic mountains and sea mounts that run parallel to trenches and subduction zones |
