Oceanic Plateau

An oceanic plateau is a large, elevated region of thickened oceanic crust built by a short pulse of voluminous basaltic volcanism, a submarine large igneous province. Plateaus stand 2 to 4 km above the surrounding abyssal seafloor and carry crust 20 to 40 km thick, far more than the normal 7 km, because a mantle-plume head delivered huge magma volumes over a few million years. The Ontong Java Plateau in the western Pacific is the largest, covering an area near that of Alaska. Their thick, buoyant crust resists subduction, so plateaus can accrete to continents and survive in the geologic record.