TY - JOUR T1 - New insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece JF - Sci. Rep. Y1 - 2013 A1 - Kilias, Stephanos P. A1 - Nomikou, Paraskevi A1 - Papanikolaou, Dimitrios A1 - Polymenakou, Paraskevi N. A1 - Athanasios Godelitsas A1 - Argyraki, Ariadne A1 - Carey, Steven A1 - Gamaletsos, Platon A1 - Theo J. Mertzimekis A1 - Stathopoulou, Eleni A1 - Goettlicher, Joerg A1 - Steininger, Ralph A1 - Betzelou, Konstantina A1 - Livanos, Isidoros A1 - Christakis, Christos A1 - Bell, Katherine Croff A1 - Scoullos, Michael AB - We report on integrated geomorphological, mineralogical, geochemical and biological investigations of the hydrothermal vent field located on the floor of the density-stratified acidic (pH   5) crater of the Kolumbo shallow-submarine arc-volcano, near Santorini. Kolumbo features rare geodynamic setting at convergent boundaries, where arc-volcanism and seafloor hydrothermal activity are occurring in thinned continental crust. Special focus is given to unique enrichments of polymetallic spires in Sb and Tl (±Hg, As, Au, Ag, Zn) indicating a new hybrid seafloor analogue of epithermal-to-volcanic-hosted-massive-sulphide deposits. Iron microbial-mat analyses reveal dominating ferrihydrite-type phases, and high-proportion of microbial sequences akin to "Nitrosopumilus maritimus", a mesophilic Thaumarchaeota strain capable of chemoautotrophic growth on hydrothermal ammonia and CO2. Our findings highlight that acidic shallow-submarine hydrothermal vents nourish marine ecosystems in which nitrifying Archaea are important and suggest ferrihydrite-type Fe3+-(hydrated)-oxyhydroxides in associated low-temperature iron mats are formed by anaerobic Fe2+-oxidation, dependent on microbially produced nitrate. PB - Macmillan Publishers Limited. All rights reserved VL - 3 ER -