Oceanic plateau

An Oceanic Plateau (also ocean plateau, Submarines plateau or Untermeerisches Plateau ) is a broad, relatively flat area of the ocean floor, which clearly rises above the height of the surrounding terrain (at least 200 m). While most oceanic plateaus consist of continental crust, and form a paragraph in many cases in the continental slope, some plateaus are the testimonies of large igneous provinces, and were produced by the discharge of large quantities of basaltic lava. Similar phenomena are the flood basalts on land, such as the Deccan Traps in India or the basalts of the Snake River Plain in the United States.

Oceanic plateaus as transitional forms

Since magmatic oceanic plateaus have a lower density than the surrounding ocean floor, they could represent a transitional stage to real continental crust. These density differences caused by the different proportions of various minerals that are involved in the formation of the rocks. Continental crust has on average the highest proportion of felsic ( feldsdpat and rich in quartz ) rocks, whereas oceanic crust is at a significantly larger proportion of mafic rocks. The rocks of oceanic plateaus are felsic than normal oceanic crust, but still more mafic than felsic.

If a tectonic plate with oceanic crust subducted under a plate carrying an oceanic plateau, the result is due to the (partial) melting of the subducting slab into the mantle magma that rises and as volcanic material emerges at the surface of the plateau. This is clearly felsic than the material of oceanic plateaus. If the plateau also subducted, so in turn creates material that contains even less mafic minerals. The circuit can thus lead to the formation of continental crust.

List of oceanic plateau

Oceanic plateau on the continental crust

  • Campbell Plateau ( South Pacific )
  • Challenger Plateau ( South Pacific )

Igneous oceanic plateau

  • Agulhas Plateau (southwest Indian Ocean )
  • Caribbean - Kolumbisches plateau ( Caribbean)
  • Exmouth Plateau ( Indian Ocean )
  • Hikurangi Plateau ( Southwest Pacific )
  • Kerguelen Plateau ( Indian Ocean )
  • Manihiki Plateau ( Southwest Pacific )
  • Mascarene Plateau ( Indian Ocean )
  • Naturaliste Plateau ( Indian Ocean )
  • Ontong Java Plateau ( Southwest Pacific )
  • Shatsky Rise ( North Pacific Ocean )
  • Vøring Plateau ( North Atlantic)
  • Wrangellia - Terran ( Northeast Pacific)
  • Yermak Plateau ( Arctic Ocean)
New Zealand Zealandia (continent) Bathymetry
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