Seawater percolates through the sea floor and is modified by chemical exchange with the surrounding rocks and rising magmatic fluid. The altered seawater is released back into the ocean at the vent site and forms a hydrothermal plume. The rising plume mixes rapidly with ambient seawater, lowering the temperature and diluting the particle concentration. The plume will continue to rise through seawater as long as it is less dense than the surrounding seawater. Once the density of the hydrothermal plume matches the density of the seawater, it stops rising and begins to disperse laterally. In a scenario like this, 90 per cent of the metals are lost to the plume and do not take part in the metal deposit formation process.
From collection: Deep Sea Minerals Volume 1A