Manganese Nodules On Ocean Floor

Across the otherworldly plains of the clarion clipperton zone some 15 000 ft below the surface of the pacific ocean are clustered manganese nodules the size of potatoes.

Manganese nodules on ocean floor.

The vents create globular or massive sulfide deposits which contain valuable metals such as silver gold copper manganese cobalt and zinc. Large areas in the cook islands coastal waters have concentrations of over 25 kilograms of manganese nodules per square metre of sea floor. The rare earth metal. Polymetallic nodules like this one made of layers of iron and manganese sit on the deep seabed.

So far only a single large area of manganese nodules has been discovered here with an area comparable to that of the penrhyn basin. It is located in the central indian ocean. This recently discovered batch located several hundred miles east of barbados is the largest yet discovered in the atlantic ocean. Ocean mining sites are usually around large areas of polymetallic nodules or active and extinct hydrothermal vents at 1 400 to 3 700 metres 4 600 to 12 100 ft below the ocean s surface.

Proponents of mining stress that manganese nodules and cobalt crusts are present as thin layers lying directly on the sea floor or on the flanks of seamounts. Manganese nodules are found scattered on the ocean floor. Deep sea mining companies are hunting for these nodules to use in the technology industry but. Polymetallic nodules also called manganese nodules are rock concretions on the sea bottom formed of concentric layers of iron and manganese hydroxides around a core.

In contrast to ore deposits on land they are thus a two dimensional resource that can theoretically be extracted with relatively little effort. As nodules can be found in vast quantities and contain valuable metals deposits have been identified as having economic interest. Though generally composed of manganese hence the name they can also be made of iron nickel copper and other metals. Why is manganese not mined on the seabed given that there are abundant manganese nodules in some parts of the ocean floor.

It is not economical to mine manganese nodules at present day world prices for manganese and associated metals in nodules.