Hydrothermal vent fluids, chemistry

Conservative Elements. Elemental Distribution Overview. Hydrothermal Vent Fluids, Chemistry of. Mid-Ocean Ridge Geochemistry and Petrology. Volcanic Helium. 

Anthropogenic Trace Elements in the Ocean. Atmospheric Input of Pollutants. Carbon Cycle. Conservative Elements. Hydrothermal Vent Fluids, Chemistry of. Marine Silica Cycle. Metal Pollution. Nitrogen Cycle. Platinum Group Elements and their Isotopes in the Ocean. Refractory Metals. River Inputs. Transition Metals and Heavy Metal Speciation. 

Authigenic Deposits. Hydrothermal Vent Fluids, Chemistry of. 

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... 

The compositions of vent fluids found on the global MOR system are of interest for several reasons how and why those compositions vary has important implications. The overarching question, as mentioned in Section 6.07.1.3, is to determine how the fluids emitted from these systems influence and control ocean chemistry, on both short and long timescales. This question is very difhcult to address in a quantitative manner because, in addition to all the heat flux and related water flux uncertainties discussed in Section 6.07.1, it also requires an understanding of the range of chemical variation in these systems and an understanding of the mechanisms and variables that control vent-fluid chemistries and temperatures. Essentially every hydrothermal vent that is discovered has a different composition (e.g.. Von Damm, 1995) and we now know that these compositions often vary profoundly on short... 

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. 

Bray, A. M. (1998). Controls on Alkali Metal Chemistry in Hydrothermal Vent Fluids for 9-10°N Latitude, East Pacihc Rise. Master s Degree, Univ. of New Hampshire, 186 pp. 

Hydrothermal venting injects fluids into seawater as buoyant, jetlike pliunes. These turbulent flows mix rapidly with seawater becoming diluted by factors of lO" to 10. This mixing eventually makes the plumes neutrally buoyant, after which they are transported laterally through the ocean basins as part of the intermediate and deepwater currents. Hydrothermal plumes have the potential to greatly affect seawater chemistry. From global estimates of hydrothermal fluid emissions and dilution ratios, a volume of seawater equivalent to the entire ocean can be entrained in the hydrothermal plumes every few thousand years. 

Edmond J. M., Campbell A. C., Palmer M. R., KlinVhammer G. P., German C. R., Edmonds H. N., Elderfield H., Thompson G., and Rona P. (1995) Time-series studies of vent-fluids from the TAG and MARK sites (1986, 1990) Mid-Atlantic Ridge a new solution chemistry model and a mechanism for Cu/Zn zonation in massive sulphide ore-bodies. In Hydrothermal Vents and Processes, Geol. Soc. Spec. Publ. 87 (eds. L. M. Parson, C. L. Walker, and D. R. Dixon), The Geological Society Publishing House, Bath, UK, pp. 77-86. 

The influence of these processes on the composition of Mesoarchean seawater is still unclear. De Ronde et al. (1997) have studied the fluid chemistry of what they believe are Archean seafloor hydrothermal vents, and have explored the implications of their analyses for the composition of contemporary seawater. They estimate that seawater contained 920 mmol Cl, 2.25 mmol Br, 2.3 mmol L i SO4, 0.037 mmolL I, 789 mmol Na, 5.1 mmol NH4, 18.9 mmol K, 50.9 mmol L Mg, 232 mmol Ca, and 4.52 mmol Sr. This composition, if correct, implies that Archean seawater was rather similar to modern seawater. 

De Ronde C. E. J., Channer R. M., Faure de R., Bray C. J., and Spooner E. T. C. (1997) Fluid chemistry of Archean seafloor hydrothermal vents implications for the composition of circa 3.2 Ga seawater. Geochim. Cosmochim. Acta 61, 4025-4042. 

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