Arctic Ocean deepest point is Litke Deep in the Eurasian Basin, at . The two major basins are further subdivided by ridges into the Canada Basin (between Alaska/Canada and the Alpha Ridge), Makarov Basin (between the Alpha and Lomonosov Ridges), Amundsen Basin (between Lomonosov and Gakkel ridges), and Nansen Basin (between the Gakkel Ridge and the continental shelf that includes the Franz Josef Land). In large parts of the Arctic Ocean, the top layer (about ) is of lower salinity and lower temperature than the rest. It remains relatively stable, because the salinity effect on density is bigger than the temperature effect.
Bonaparte Basin over thick under the ocean. The basin originated from the Cambrian period to the Cenozoic era, 540 to 360 million years ago. Limestone, sandstone, mudstone, basalt, coal and glacial sediments are embedded in the basin. It contains several oil and natural gas fields amounting to 18% of Australia's known reserves of natural gas. Total estimated reserves are of oil and of gas. The sedimentary basin partially overlays the Kalkaindji province, the Birrindudu Basin and Wolfe Basin. The Bonaparte Basin has deposits of lead, zinc, iron, gold and smaller coal deposits on land, mineralised in sandstone deposits. There were studies on