@article {042_Kolumbo, title = {New insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece}, journal = {Sci. Rep.}, volume = {3}, year = {2013}, pages = {2421}, publisher = {Macmillan Publishers Limited. All rights reserved}, abstract = {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 ({\textpm}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.}, doi = {10.1038/srep02421}, author = {Kilias, Stephanos P. and Nomikou, Paraskevi and Papanikolaou, Dimitrios and Polymenakou, Paraskevi N. and Athanasios Godelitsas and Argyraki, Ariadne and Carey, Steven and Gamaletsos, Platon and Theo J. Mertzimekis and Stathopoulou, Eleni and Goettlicher, Joerg and Steininger, Ralph and Betzelou, Konstantina and Livanos, Isidoros and Christakis, Christos and Bell, Katherine Croff and Scoullos, Michael} }