Story: Marine minerals

Production of mineral sediments

Production of mineral sediments

This diagram shows the process by which vents on the ocean floor spew out a cocktail of minerals. Cold sea water enters cracks in an underwater volcano. It descends hundreds of kilometres into the earth, where it is heated as it nears molten rock (magma). The heated sea water also becomes more acidic, and starts to dissolve elements such as manganese, iron, silicon and other minerals from the surrounding rocks. The heated fluid starts to rise, and is eventually expelled through vents on the sea floor. As the hydrothermal fluid mixes with cold sea water, the metals in solution precipitate as fine-grained particles, which form dark-coloured plumes called black smokers. Some of the material that is precipitated falls on the sea floor, and gradually enriches the surrounding area in metals.

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Source: GNS Science

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How to cite this page:

Ian Wright, 'Marine minerals - Nodules, crusts and vents', Te Ara - the Encyclopedia of New Zealand, (accessed 30 June 2022)

Story by Ian Wright, published 12 Jun 2006