In this schematic drawing of the TAG active hydrothermal mound,
hydrothermal fluid rises rapidly and exits the mound at the Black
Smoker Complex. Cold calcium- and sulfate-rich seawater is entrained
into the mound, where it mixes with hydrothermal fluid. The mixing
causes anhydrite, pyrite, and chalcopyrite to precipitate inside
the mound. This precipitation increases the acidity of the hydrothermal
fluid. Zinc and other elements, such as silver, gold, and cadmium,
dissolve in this acidic fluid, allowing them to be carried by
the white smoker fluid to the edges of the mound at the "Kremlin"
area. Here the cooler temperatures within white smoker chimney
walls cause the elements to precipitate.
〔Woods Hole Oceanographic InstitutionのDeep Ocean
Exploration Instituteの『Related
Topics』の中の『Hydrothermal
Vent Systems』から〕 |