1.5 trillion tons of metal nodules (cobalt, copper, manganese and nickel) are estimated to exist in the Pacific Ocean soil, covering their deepest regions, according to Walter Sulivan's article in “N.Y. Times. ”
Although lumps have been found at the bottom of Lake Michigan, they first appear in saltwater and in very deep places about six to eight kilometers.
The richest deposits known are in a narrow area that runs from the central Pacific south of Hawaii and east to Mexico.
These nodules are believed to be formed by bacteria that extract and deposit dissolved metals in seawater.
It has been estimated that 10 million tons of nodules are produced per year. Manganese is the basis of these nodules, but the metal of major economic interest is nickel.
For a while, a number of major industries have been developing technology to pick up the lumps and extract the metals.