Chemistry of hydrothermal solutions from the southern Juan de Fuca Ridge

Journal of Geophysical Research B: Solid Earth
By:  and 

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Abstract

Fluids from three vent fields on the southern Juan de Fuca Ridge were sampled in September 1984 using the DSRV Alvin. The fluids are uniquely high in both chloride, which ranges up to twice the seawater value, and in metal content. Simple vapor-liquid phase separation could not have produced both the high chlorinity and gas concentrations observed in these fluids. The cause of the elevated chlorinity can not be uniquely identified but may be the result of either or a combination of two processes: (1) subsurface formation of a degassed brine and subsequent mixing of a small amount of this brine with a hydrothermal seawater which has not undergone a phase separation and (2) dissolution of a chloride-rich phase combined with a possible small loss of gas during sampling procedures. Although measured temperatures were all less than 300°C, quartz geothermometry suggests that the fluids have equilibrated at greater than 340°C. Quartz geobarometry is also in agreement with geophysical estimates of depth to the local magma chamber.

Additional publication details

Publication type Article
Publication Subtype Journal Article
Title Chemistry of hydrothermal solutions from the southern Juan de Fuca Ridge
Series title Journal of Geophysical Research B: Solid Earth
DOI 10.1029/JB092iB11p11334
Volume 92
Issue B11
Year Published 1987
Language English
Publisher AGU Publications
Contributing office(s) Pacific Coastal and Marine Science Center
Description 3 p.
First page 11334
Last page 11346