Hydrothermal vents

Hot vents ‘black smokers’ - hot hydrothermal fluid containing abundant metal sulphides reaches the sea floor directly & precipitates on emerging into cold seawater forming a tower or chimney. Warm vents - where hot hydrothermal fluid is cooled by seawater permeating the sediment. ‘White smokers’ emit lighter-hued minerals, such as those containing barium, calcium, and silicon. These vents also tend to have lower temperature plumes. These are alkaline hydrothermal vents.