Open AccessANTIMONY FIXATION IN SOLID PHASES AT THE HYDROTHERMAL FIELD OF KOLUMBO SUBMARINE ARC-VOLCANO (SANTORINI): DEPOSITION MODEL AND ENVIRONMENTAL IMPLICATIONS
Author(s) -
Stephanos P. Kilias,
M. Gousgouni,
Athanasios Godelitsas,
P. Gamaletsos,
T. J. Mertzimekis,
P. Nomikou,
Ariadne Argyraki,
J. Goettlicher,
Ralph Steininger,
Dimitros Papanikolaou
Publication year - 2017
Publication title -
deltio tīs ellīnikīs geōlogikīs etaireias/deltio tīs ellīnikīs geōlogikīs etaireias
Language(s) - English
Resource type - Journals
eISSN - 2529-1718
pISSN - 0438-9557
DOI - 10.12681/bgsg.14276
Subject(s) - pyrite , hydrothermal circulation , antimony , geochemistry , sulfide , geology , seawater , ferrihydrite , volcano , submarine volcano , mineralogy , environmental chemistry , chemistry , inorganic chemistry , oceanography , organic chemistry , adsorption , seismology
Antimony, an emergent global contaminant, that is hydrothermally discharged along with other epithermal metals(-loids) (Au, As, Hg, Ag, Tl, Ag) onto Kolumbo volcano’s shallow (<500 m water depth) crater seabed, is fixed either in pyrite, orpiment-like As-sulfides, and ferrihydrite-like Fe-oxy(hydro)oxides, or forms independent Pb(Zn)- Sb sulfosalts, of layered Sb-rich (up to 2.2 wt%) chimneys. High concentrations of Sb (≤ 27.2 wt%) are found in early colloform chemically-zoned hydrothermal pyrite, and later orpiment (As2S3)-type As sulfide phases(≤16.09 wt %), along individual micronscale growth zones. Antimony in pyrite may occur in the relatively more toxic trivalent (or lower valence) (Sb3+) rather than pentavalent (Sb5+) forms. Lead (Pb) always occurs with Sb in growth zones where the abundances of Sb and Pb vary inversely with Fe and S, suggesting that Sb and Pb occur either as homogeneously distributed sulfosalt nanoparticles of Sb and Pb and/or lattice bound trace elements. These findings indicate the solid phases that fix Sb on the seafloor are crucial for high- grade concentration during shallow-water hydrothermal polymetallic mineralization, and reducing the high hydrothermal flux of this notorious environmental toxin to seawater, near the fishing area of Santorini that is also one of the most popular tourist places in the world.