Hydrothermal vent fluids

Butterfield, V.A., McDuff, R.E., Franklin, J. and Wheat, C.G. (1994) Geochemistry of hydrothermal vent fluids from Middle Valley, Juan de Fuca Ridge. In Mottl, M.J., Davis, E.E., Fi.sher, A.T. and Slack, J.F. (eds.). Proceedings of the Ocean Drilling Program. Sci. Proc., 139, 395-410. 

Lithium is enriched in high temperature (c. 350°C) vent fluids by a factor of 20-50 relative to seawater (Edmond et al. 1979 Von Damm 1995). The Li isotopic compositions of marine hydrothermal vent fluids ranged from MORB-like to heavier compositions (see... 

Bouman C, Vroon PZ, Elliott TR, Schwieters JB, Hamester M (2002) Determination of lithium isotope compositions by MC-ICPMS (Thermo Finnigan MAT Neptune). Geochim Cosmochim Acta 66 A97 Bray AM (2001) The geochemistry of boron and lithium in mid-ocean ridge hydrothermal vent fluids. PhD thesis. University of New Hampshire, 125 p... 

Theoretical estimates of energy available from hydrothermal vent fluids for various chemosynthesis reactions used by vent microbes. Oxidative reactions are shown as dashed lines and reductive reactions as solid lines. Iron reduction provides too little energy to appear on plot. H2 oxidation was not calculated. Source From Leveille, R. J., and S. K. Juniper (2003). Biogeochemistry of Marine Systems, Blackwell Publications, pp. 238-292. 

Seyfried, W.E., Jr., Seewald, J.S., Berndt, M.E., Ding, K., Foustoukos, D.I. 2003. Chemistry of hydrothermal vent fluids from the Main Endeavor Field, northern Juan de... 

Toxic heavy metals Cd 2-5 mM, bacteria and archaeans Ni 2.5 mM, Co 20 mM, Zn 12 mM, Cd 2.5mM, Ralstonia eutrophus Algae, e.g., Euglena and Chlorella can grow in Cd, Zn, and Co at mM concentrations Submarine hydrothermal vent fluids and sulfides some high-metal-containing lakes... 

MgO is a key element in the discussion of hydrothermal systems. It is an important element in many igneous phases and in alteration phases. The depletion of magnesium in hydrothermal vent fluids was originally seen as evidence that the... 

Figure 9 Periodic table of the elements showing the elements that are enriched in hydrothermal vent fluids relative to seawater (red), depleted (blue) and those which have been shown to exhibit both depletions and enrichments in different hydrothermal fluids (yellow) relative to seawater. All data are normalized to the chloride content of seawater in order to evaluate true gains and losses relative to the starting seawater concentrations.

The reaction zone represents the highest pressure and temperature (likely >400 °C) conditions reached by hydrothermal fluids during their subsurface circulation it is here that hydrothermal vent fluids are believed to acquire much of their chemical signatures (Section... 

Bray A. M. and Von Damm K. L. (2003a) The role of phase separation and water—rock reactions in controlling the boron content of mid-ocean ridge hydrothermal vent fluids. Geochim. Cosmochim. Acta (in revision). 

Von Damm K. L. (2000) Chemistry of hydrothermal vent fluids from 9-10°N, East Pacific Rise time zero the immediate post-eruptive period. J. Geophys. Res. 105, 11203-11222. 

Von Damm K. L., Oosting S. E., Kozlowski R., Buttermore L. G., Colodner D. C., Edmonds H. N., Edmond J. M., and Grebmeier J. M. (1995) Evolution of East Pacific Rise hydrothermal vent fluids following a volcanic eruption. Nature 375, 47-50. 

Examples of environments where local high degrees of supersaturation are encountered include those associated with discharge of hydrothermal vent fluids into cold ocean water, regions where streams of highly acidic solutions mix with neutral pH water, zones of mixing between groundwater fluids, and sites of evaporation of soil water solutions. 

Hydrocarbons in hydrothermal vent fluids the role of chromium-bearing catalysts. Science, 302, 1002-5. 

As pointed out by Seal et al. (2000), many studies of ancient hydrothermal systems have utilized equilibrium sulfate-sulfide sulfur isotope fractionation models, but these should be applied with great caution. As shown in Figure 9, seafloor hydrothermal vent fluid 5" Sh2S values do not conform to simple equilibrium fractionation models. Shanks et al. (1981) first showed experimentally that sulfate in seawater-basalt systems is quantitatively reduced at temperatures above 250°C when ferrous minerals like the fayalitic olivine are present. When magnetite is the only ferrous iron-bearing mineral in the system, sulfate-reduction proceeds to sulfate-sulfide equilibrium, but natural basalts contain ferrous iron-bearing olivine, pyroxene, titanomagnetite, and iron-monosulfide solid-solution (mss) (approximately pyrrhotite). It is the anhydrite precipitation step... 

Figure 7. Plots of AD, and A 0 versus spreading rate for MOR hydrothermal vent fluids. These relations show that extent of water-rock reaction is greater in slower spreading ridges, perhaps due to longer snb-surface convective hydro-thermal flow paths.

Physical and Chemical Characteristics of Hydrothermal Vent Fluids... 

The Chemical Composition of Hydrothermal Vent Fluids and Precipitates... 

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