Knowra Oceanic basin Oceanic basin An oceanic basin is a broad, deep region of seafloor bounded by continental margins, mid-ocean ridges, or other elevated features. Its shape reflects the formation, movement, and recycling of oceanic crust.
Oceanic crust : The dense basaltic crust beneath the oceans, formed mainly at mid-ocean ridges. Its creation and destruction shape the basin floor over geological time.
Seafloor spreading : The process by which new oceanic crust forms at a ridge and moves outward on both sides. It enlarges ocean basins as their floors move away from spreading ridges.
Pacific Ocean : The largest ocean on Earth, bordered by Asia, Australia, the Americas, and Antarctica. Its basin is ringed by subduction zones and contains a vast network of trenches.
Sedimentary basin : A region of prolonged subsidence where thick layers of sediment accumulate. It is defined by sediment accumulation, unlike an oceanic basin’s seafloor setting.
Continental margin : The submerged edge of a continent, including its shelf, slope, and rise. It commonly marks the boundary between an oceanic basin and a continent.
Subduction : The descent of one tectonic plate beneath another into the mantle. It removes oceanic crust and can shrink a basin at its margins.
Atlantic Ocean : The ocean between the Americas and Europe and Africa, widening around the Mid-Atlantic Ridge. Its basin illustrates ocean-floor expansion away from a central ridge.
Foreland basin : A sediment-filled depression that forms beside a mountain belt as the lithosphere bends under its weight. This basin forms beside mountains on a plate, not as a broad ocean-floor region.
Mid-ocean ridge : A continuous underwater mountain chain where tectonic plates diverge and new oceanic crust forms. Ridges divide ocean floors into basins and stand high above their abyssal plains.
Plate tectonics : The theory that Earth's lithosphere consists of moving plates whose interactions shape the surface. Its moving plates drive the formation and long-term rearrangement of ocean basins.
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