DEPOSITIONAL ENVIRONMENT AND WORLD DISTRIBUTION OF MARINE PHOSPHORITES

Phosphorite is an important nonmetallic mineral resource in the ocean. The total amount of the P₂O₅ resource is about 20×10⁹ tons in the ocean. Marine phosphorites are widely distributed on the shelf, continental slope and submarine plateau in an oxidizing or suboxidizing environment at water depth of hundreds to several thousands of meters. The richest phosphorites are usually distributed in the area closing to the oceanic upwelling current. According to their geographic location, tectonic position, and geomorphology, marine phosphorites are divided into 8 distribution zones in the world, including the eastern Pacific continental margin, the western Pacific continental margin, the Pacific seamounts and deep basin, the eastern Atlantic continental margin, the western Atlantic continental margin, the Atlantic seamounts and basin-range landform, the Indian Ocean continental margin and the seamounts and basin-range landform in the Indian Ocean.