Manganese nodule

A mineral concretion on the deep ocean floor that grows around a nucleus and contains abundant manganese and iron alongside other metals.

Hydrogenetic growth: The slow precipitation of metals from seawater onto a solid surface. This process builds nodules from metals supplied directly by seawater.
Deep-sea mining: The extraction of mineral resources from the seabed and its subsurface. Nodules are a major target of proposed mining on abyssal plains.
Abyssal plain: A broad, nearly level region of the deep-ocean floor, usually covered by fine sediment. Nodules are scattered across these deep seafloor landscapes.
Marine sediment: Material that settles and accumulates on the floor of seas and oceans. Nodules form on or within the sediments covering the deep-ocean floor.
Diagenetic growth: The formation or alteration of minerals through chemical processes in sediments after deposition. Porewater metals released from sediment can add layers to nodules.
Polymetallic nodule mining: The collection of seabed nodules for their mixture of valuable metals. This mining method specifically targets manganese nodules and related deposits.
Deep-sea benthos: The organisms that live on or in the deep-ocean floor. Nodules provide hard surfaces and habitat in otherwise soft abyssal sediment.
Metal flux: The rate at which a metal is supplied to or removed from a defined environment. Different metal supply rates help determine nodule composition and growth.
Manganese oxide: A group of manganese- and oxygen-bearing minerals that commonly occurs in ocean-floor deposits. Manganese oxides make up much of a nodule’s dark mineral mass.
International Seabed Authority: The intergovernmental organization that regulates mineral-related activities in the international seabed area. It oversees exploration contracts and develops rules for mining nodules beyond national jurisdiction.

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