oceanic crust spreading

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• Oceanic crust — Age of oceanic crust. The red is most recent, and blue is the oldest. Oceanic crust is the part of Earth s lithosphere that surfaces in the ocean basins. Oceanic crust is primarily composed of mafic rocks, or sima, which is rich in iron and… …   Wikipedia

• Oceanic trench — Oceanic crust is formed at an oceanic ridge, while the lithosphere is subducted back into the asthenosphere at trenches. The oceanic trenches are hemispheric scale long but narrow topographic depressions of the sea floor. They are also the… …   Wikipedia

• Oceanic core complex — An oceanic core complex (OCC), or megamullion, is a seabed geologic feature that forms a long ridge perpendicular to a mid ocean ridge. It contains smooth domes that are lined with transverse ridges like a corrugated roof. They can vary in size… …   Wikipedia

• Oceanic basin — Diagrammatic cross section of an ocean basin, showing the various geographic features Hydrologically, an oceanic basin may be anywhere on Earth that is covered by seawater, but geologically ocean basins are large geologic basins that are below… …   Wikipedia

• Oceanic plateau — An oceanic plateau (also submarine plateau) is a large, relatively flat submarine region that rises well above the level of the ambient seabed.[1] While many oceanic plateaus are composed of continental crust, and often form a step interrupting… …   Wikipedia

• Oceanic zone — Marine habitats The oceanic zone is the deep open ocean water that lies off the continental slopes Littoral zone Intertidal zone …   Wikipedia

• oceanic ridge — Continuous, submarine mountain chain extending approximately 50,000 mi (80,000 km) through all the world s oceans, separating them into distinct basins. The main ridge extends down the middle of the Atlantic Ocean, passes between Africa and… …   Universalium

• oceanic plateau — or submarine plateau Large submarine elevation rising sharply at least 660 ft (200 m) above the surrounding seafloor and having an extensive, relatively flat or gently tilted summit. Most plateaus are steplike interruptions of the continental… …   Universalium

• Seafloor spreading — Age of oceanic crust; youngest (red) is along spreading centers. Seafloor spreading is a process that occurs at mid ocean ridges, where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge. Seafloor… …   Wikipedia

• sea-floor spreading — noun (geology) The process by which new oceanic crust is generated at oceanic ridges by the convective upswelling of magma • • • Main Entry: ↑sea * * * sea floor spreading «SEE FLR, FLOHR», the process by which the sea floor is being continuously …   Useful english dictionary

• seafloor spreading — Theory that oceanic crust forms along submarine mountain zones, known collectively as the oceanic ridge system, and spreads out laterally away from them. This idea, proposed by U.S. geophysicist Harry H. Hess (1906–1969) in 1960, was pivotal in… …   Universalium