New insights into hydrothermal vent processes in the unique shallow-submarine arc-volcano, Kolumbo (Santorini), Greece.
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 Fe(3+)-(hydrated)-oxyhydroxides in associated low-temperature iron mats are formed by anaerobic Fe(2+)-oxidation, dependent on microbially produced nitrate.
National and Kapodistrian University of Athens, Faculty of Geology and Geoenvironment, Panepistimiopoli Zografou, Athens, Greece. kilias@geol.uoa.gr
Stephanos P
SP
Kilias
Paraskevi
P
Nomikou
Dimitrios
D
Papanikolaou
Paraskevi N
PN
Polymenakou
Athanasios
A
Godelitsas
Ariadne
A
Argyraki
Steven
S
Carey
Platon
P
Gamaletsos
Theo J
TJ
Mertzimekis
Eleni
E
Stathopoulou
Joerg
J
Goettlicher
Ralph
R
Steininger
Konstantina
K
Betzelou
Isidoros
I
Livanos
Christos
C
Christakis
Katherine Croff
KC
Bell
Michael
M
Scoullos
D001105:Archaea / Q000302:isolation & purification*; D006115:Greece; D060086:Hydrothermal Vents / Q000737:chemistry* / Q000382:microbiology*; D008670:Metals / Q000032:analysis*; D018707:Volcanic Eruptions / Q000032:analysis*
D008670:Metals