sea bed exploitation

Marine mineral resources extend far beyond those presently exploited; minerals are derived from two separate types of marine sources: from sedimentary deposits underlying the continental shelves and from inshore deposits on the surface of the continental shelves. By far the most valuable of the mineral resources exploited from marine environments is petroleum. Offshore placer deposits on the surface of the continental shelves yield gold, platinum, and tin. On the floors of the world's oceans manganese nodules are found as a result of pelagic sedimentation or precipitation; they are small, irregular, black to brown, friable, laminated concretionary masses consisting primarily of manganese salts and manganese-oxide minerals. (Source: PARCOR / BJGEO)