Geochemical evidence for mixing of magmatic fluids with seawater, Nisyros hydrothermal system, Greece

Details

Serval ID
serval:BIB_3FCCDAEB3686
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Geochemical evidence for mixing of magmatic fluids with seawater, Nisyros hydrothermal system, Greece
Journal
Bulletin of Volcanology
Author(s)
Brombach T., Caliro S., Chiodini G., Fiebig J., Hunziker J.C., Raco B.
ISSN-L
0258-8900
Publication state
Published
Issued date
2003
Peer-reviewed
Oui
Volume
65
Pages
505-516
Language
english
Notes
ISI:000185601400004
Abstract
The chemical and isotopic compositions (deltaD(H2O), delta(18)O(H2O),
delta(18)O(CO2), delta(13)C(CO2), delta(34)S, and He/N-2 and He/Ar
ratios) of fumarolic gases from Nisyros, Greece, indicate that both
arc-type magmatic water and local seawater feed the hydrothermal system.
Isotopic composition of the deep fluid is estimated to be
+4.9+/-0.5parts per thousand for delta(18)O and -11+/-5parts per
thousand for deltaD corresponding to a magmatic water fraction of 0.7.
Interpretation of the stable water isotopes was based on liquid-vapor
separation conditions obtained through gas geothermometry. The H-2-Ar,
H-2-N-2, and H-2-H2O geothermometers suggest reservoir temperatures of
345+/-15 degreesC, in agreement with temperatures measured in deep
geothermal wells, whereas a vapor/liquid separation temperature of
260+/-30 degreesC is indicated by gas equilibria in the
H2O-H-2-CO2-CO-CH4 system. The largest magmatic inputs seem to occur
below the Stephanos-Polybotes Micros crater, whereas the marginal
fumarolic areas of Phlegeton-Polybotes Megalos craters receive a smaller
contribution of magmatic gases.
Create date
05/12/2012 20:20
Last modification date
20/08/2019 13:37
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