The Heavy-Metal Fingerprint of the Irinovskoe Hydrothermal Sulfide Field, 13°20′ N, Mid-Atlantic Ridge

A number of Cd-, Pb-, Ag- and Sb(±As)-bearing minerals are found in the Zn-rich smoker chimneys Irinovskoe hydrothermal sulfide field, 13°20′ N, Mid-Atlantic Ridge. Sulfide samples were studied using optical microscopy, SEM/EDS, XRD, EBDS, ICP-MS thermodynamic approaches. The consist major sphalerite (including Cd-bearing type with up to 41.38 wt% Cd) wurtzite, subordinate opal, pyrite, chalcopyrite Fe-oxyhydroxides, as well accessory native sulfur, baryte, secondary copper sulfides, galena, CdS phase (most likely hawleyite), pyrrhotite, isocubanite, acanthite, Ag–Cu–Sb(±As)-bearing minerals, gold, anglesite, gypsum, smectites, naumannite lollingite. main source metals for formation sulfides was mafic rocks, a role from ultramafic rocks. Crystallization most at low temperatures (<120 °C) under acidic/reducing conditions S activity could be initiated by magmatic input, which is supported negative isotopic composition bulk samples. finding Cd-rich low-temperature mineral assemblage significantly expands temperature limits their possible formation. high Cd contents easily soluble presence should taken into account future mining processing seafloor fields.