Hydrothermal fluids heat flux

Torgersen, T., Clarke, W. B. (1992) Geochemical constraints on formation fluid ages, hydrothermal heat flux, and crustal mass transport mechanisms at Cajon Pass. J. Geophys. 

Of course, high-temperature hydrothermal fluids may not be entirely responsible for the transport of all the axial hydrothermal heat flux. Elderfield and Schultz (1996) considered a uniform distribution, on the global scale, in... 

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... 

In practice, W is directly inferred from heat flow and chemical mass balances. Warm hydro-thermal flow is a major sink for dissolved oceanic The Mg + in the warm hydrothermal fluid is removed quantitatively by reaction with basalt. Because the flux of Mg + into the ocean in river waters and the competing sinks (e.g. clays) can be estimated, the known Mg + concentration in sea water can be used to determine W. This argument is independent of CO2. 

This model also works well for the Archaean, with its likely higher mantle heat flow and smaller continental mass and is consistent with calculations which show that there was a much higher flux of hydrothermal fluid into the early oceans compared to the present day (Section 5.4.2). In addition, it is consistent with the many observations of carbonate alteration in Archaean mafic and ultramafic rocks (Rose et al., 1996 Nakamura Kato, 2004). Nakamura and Kato (2004) proposed a global carbon flux of 3.8 x 1013 mol/yr into the ocean floor at 3.46 Ga, an order of magnitude greater than the modern carbon flux of veined MORB (Table 5.3). If these Archaean fluxes are used in Zahnle and Sleep s (2002) ingassing-outgassing... 

Soon after the discovery of mantle helium in seawater, noble gases were applied to studies of hydrothermal systems. Originally, these studies were focused on the source of the fluids emanating from hydrothermal vents as well as the related heat flux. More recent studies use the full set of noble gases to infer processes of the formation and dynamics of hydrothermal systems at the sea floor. 

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