Effect of boiling on the acidity of hydrothermal solutions

  • Chris BallhausEmail author
  • Fabian Gäb
  • Dieter Garbe-Schönberg
  • Michael Staubwasser
Original Paper


Natural seawater and H2O–NaCl solutions were equilibrated along the two-phase (liquid–vapor) curves between 150 and 390 °C to re-examine the effect of liquid–vapor phase separation on element fractionations between saline brines and vapor phases. The experimental setup allows vapor and brine to be sampled separately at in situ P–T conditions. Experimental vapor pressure is constrained by temperature and the electrolyte concentration of the brines. With increasing temperature, dissolved electrolytes react with increasing temperature to hydroxides and HCl, in both seawater and H2O–NaCl solutions. The extent of hydrolysis is more pronounced in seawater than in H2O–NaCl solutions because seawater contains, in addition to NaCl, a range of other electrolytes capable of hydrolysis. Associated HCl has a great affinity to fractionate to the vapor phase when phase separation occurs. At 365 °C, halite-saturated vapor phases have a pH25 (pH after condensation to 25 °C) of 1.8 (seawater) and 2.8 (H2O–NaCl brines). Our data suggest that boiling of hydrothermal solutions followed by mixing of vapor condensates with seawater can impose pH25 values as acidic as the most acidic natural hydrothermal solutions vented on the ocean floor.


Acidity Hydrothermal solutions Phase separation Seawater H2O–NaCl system Marine impacts 



This study would not have been possible without the ingenuity of Dieter Lülsdorf, Thomas Schulz, and Henrik Blanchard who designed and built the autoclave and its periphery. The XRD analyses were carried out by Hans-Henning Friedrich. Comments by Thomas Driesner and Raul Fonseca on an earlier version of the manuscript helped clarify many points. Comments by three reviewers and editorial handling by Jochen Hoefs are much appreciated. Financial support by the DFG was provided by grants Ba 964/31 and 34 to Chris Ballhaus.


  1. Ahrens TJ, O’Keefe JD (1983) Impact of an asteroid or comet in the ocean and extinction of terrestrial life. J Geophys Res 88(suppl.):A799–A806CrossRefGoogle Scholar
  2. Armellini FJ, Tester JW (1993) Solubility of sodium chloride and sulfate in sub- and supercritical water vapor from 450 to 550 and 100–250 bar. Fluid Phase Equilib 84:123–142CrossRefGoogle Scholar
  3. Ballhaus C (1993) Redox states of lithospheric and asthenospheric upper mantle. Contrib Mineral Petrol 114:331–348CrossRefGoogle Scholar
  4. Berndt ME, Seyfried WE Jr (1997) Calibration of Br/Cl fractionation during subcritical phase separation of seawater: Possible halite at 9 to 10°N East Pacific Rise. Geochim Cosmochim Acta 61:2849–2854CrossRefGoogle Scholar
  5. Bischoff JL (1991) Densities of liquids and vapors in boiling H2O–NaCl solutions: a PVTX summary from 300° to 500 °C. Am J Sci 291:309–338CrossRefGoogle Scholar
  6. Bischoff JL, Pitzer K (1989) Liquid–vapor relations for the system H2O–NaCl: summary of the P–T-x surface from 300 to 500 °C. Am J Sci 289:217–248CrossRefGoogle Scholar
  7. Bischoff JL, Rosenbauer RJ (1983) A note on the chemistry of seawater in the range 350 to 500 °C. Geochim Cosmochim Acta 47:139–144CrossRefGoogle Scholar
  8. Bischoff JL, Rosenbauer RJ (1988) Liquid-vapor relations in the critical region of the system NaCl–H2O from 380 to 415 °C: a refined determination of the critical point and two-phase boundary of seawater. Geochim Cosmochim Acta 52:2121–2126CrossRefGoogle Scholar
  9. Bischoff JL, Seyfried WE (1978) Hydrothermal chemistry of seawater from 25° to 350 °C. Am J Sci 278:838–860CrossRefGoogle Scholar
  10. Bischoff JL, Rosenbauer RJ, Fournier RO (1996) The generation of HCl in the system CaCl2–H2O: vapor–liquid relations from 380 to 500 °C. Geochim Cosmochim Acta 60:7–16CrossRefGoogle Scholar
  11. Coumou D, Driesner T, Weis P, Heinrich CA (2009) Phase separation, brine formation, and salinity variation at Black Smoker hydrothermal systems. Journ Geophys Res 114:B03212. CrossRefGoogle Scholar
  12. Craddock PR, Bach W (2010) Insights into magmatic–hydrothermal processes in the Manus back-arc basin as recorded by anhydrite. Geochim Cosmochim Acta 74:5514–5536CrossRefGoogle Scholar
  13. Ding K, Seyfried WE Jr, Zhanga Z, Tivey MK, Von Damm KL, Bradley A (2005) The in situ pH of hydrothermal fluids at mid-ocean ridges. Earth Planet Sci Lett 237:167–174CrossRefGoogle Scholar
  14. Dolejš D, Manning CE (2010) Thermodynamic model for mineral solubility in aqueous fluids: theory, calibration and application to model fluid-flow systems. Geofluids 10:20–40Google Scholar
  15. Douville E, Charlou JL, Oelkers EH, Bienvenu P, Jove Colon CF, Donval JP, Fouquet Y, Prieur D, Appriou P (2002) The rainbow vent fluids (36°14N, MAR): the influence of ultramafic rocks and phase separation on trace metal content in Mid-Atlantic Ridge hydrothermal fluids. Chem Geol 184:37–48CrossRefGoogle Scholar
  16. Driesner T, Heinrich CA (2007) The system H2O–NaCl. Part I: Correlation formulae for phase relations in temperature-pressure-composition space from 0 to 1000 °C, 0 to 5000 bar, and 0 to 1 NaCl. Geochim Cosmochim Acta 71:4880–4901CrossRefGoogle Scholar
  17. Foustoukos DI, Seyfried WE Jr (2007) Fluid phase separation processes in submarine hydrothermal systems. Rev Miner Geochem 65:213–239CrossRefGoogle Scholar
  18. Gäb F, Ballhaus C, Siemens J, Heuser A, Lissner M, Geisler T, Garbe-Schönberg D (2017) Siderite cannot be used as CO2 sensor for Archaean atmospheres. Geochim Cosmochim Acta 214:209–225CrossRefGoogle Scholar
  19. Gamo T, Okamura K, Charlou J-L, Urabe T, Auzende J-M, Ishibashi J, Shitashimi K, Chiba H (1997) Acidic and sulfate-rich hydrothermal fluids from the Manus back-arc basin. Papua New Guinea Geology 25:139–142Google Scholar
  20. Gamo T, Ishibashi J, Tsunogai U, Okamura K, Chiba H (2006) Unique geochemistry of submarine hydrothermal fluids from arc–back-arc settings of the Western Pacific. in back-arc spreading systems: geological, biological, chemical, and physical interactions. Geophys Monogr Series 166:147–161Google Scholar
  21. Hannington MD (2014) Volcanogenic massive sulfide deposits. In Treatise on Geochem 2nd Ed. 463–488
  22. Hannington MD, De Ronde CEJ, Petersen S (2005) Sea-floor tectonics and submarine hydrothermal systems. Econ Geol 100th Anniv 111–141Google Scholar
  23. Haymon RM, Kastner M (1986) Caminite: a new magnesium-hydroxide-sulfate-hydrate mineral found in a submarine hydrothermal deposit, East Pacific Rise, 21°N. Amer Min 71:819–825Google Scholar
  24. Heggie TW, Heggie TM, Heggy TJ (2009) Death by volcanic laze. Wilderness Environ Med 20:101–103CrossRefGoogle Scholar
  25. Ho PC, Palmer DA (1996) Ion association of dilute aqueous sodium hydroxide solutions to 600 °C and 300 MPa by conductance measurements. J Sol Chem 25:711–729CrossRefGoogle Scholar
  26. Janecky DR, Seyfried WE Jr (1983) The solubility of magnesium-hydroxide-sulfate-hydrate in seawater at elevated temperatures and pressures. Am J Sci 283:831–860CrossRefGoogle Scholar
  27. Janecky DR, Seyfried WE Jr (1986) Hydrothermal serpentinization of peridotite within the oceanic crust: experimental investigations of mineralogy and major element chemistry. Geochim Cosmochim Acta 50:1357–1378CrossRefGoogle Scholar
  28. Keefer KD, Hochella MF, De Jong BHWS (1981) The structure of the magnesium hydroxide sulfate hydrate MgSO4·1/3 Mg(OH)2·1/3H2O. Acta Crystallogr B37:1003–1006CrossRefGoogle Scholar
  29. Koschinsky A, Garbe-Schönberg D, Sander S, Schmidt K, Gennerich H-H, Strauss H (2008) Hydrothermal venting at pressure-temperature conditions above the critical point of seawater, 5°S on the Mid-Atlantic Ridge. Geology 36:615–618CrossRefGoogle Scholar
  30. Kusakabe M, Komoda Y, Takano B, Abiko T (2000) Sulfur isotopic effects in the disproportionation reaction of sulfur dioxide in hydrothermal fluids: implications for the ∂34S variations of dissolved bisulfate and elemental sulfur from active crater lakes. J Volcanol Geotherm Res 97:287–307CrossRefGoogle Scholar
  31. Le Bris N, Sarradin P-M, Pennec S (2001) A new deep-sea probe for in situ pH measurement in the environment of hydrothermal vent biological communities. Deep-Sea Res 48:1941–1951CrossRefGoogle Scholar
  32. Liebscher A (2007) Experimental studies in model fluid systems. Rev Miner 65:15–47CrossRefGoogle Scholar
  33. Liebscher A, Lüders V, Heinrich W, Schettler G (2006) Br/Cl signature of hydrothermal fluids: liquid–vapour fractionation of bromine revisited. Geofluids 6:113–121CrossRefGoogle Scholar
  34. Oosting SE, Von Damm KL (1996) Bromide/chloride fractionation in seafloor hydrothermal fluids from 9 to 10°N East Pacific Rise. Earth Planet Sci Lett 144:133–145CrossRefGoogle Scholar
  35. Palmer DA, Simonson JM, Jensen JB (2004) Partitioning of electrolytes to steam and their solubilities in steam. In Palmer DA, Fernandez-Prini R, Harvey AH (eds) Aqueous systems at elevated temperatures and pressures: physical chemistry in water, steam and hydrothermal solutions, 409–439Google Scholar
  36. Pester NJ, Ding K, Seyfried WE Jr (2015) Vapor–liquid partitioning of alkaline earth and transition metals in NaCl-dominated hydrothermal fluids: an experimental study from 360 to 465 °C, near-critical to halite saturated conditions. Geochim Cosmochim Acta 168:111–132CrossRefGoogle Scholar
  37. Pokrovski GS, Roux J, Harrichoury J-C (2005) Fluid density control on vapor-liquid partitioning of metals in hydrothermal systems. Geology 33:657–660CrossRefGoogle Scholar
  38. Pokrovskii V (1999) Calculation of the standard partial molal thermodynamic properties and dissociation constants of aqueous HCl° and HBr° at temperatures to 1000 °C and pressures to 5 kbar. Geochim Cosmochim Acta 63:1107–1115CrossRefGoogle Scholar
  39. Reeves EP, Seewald JS, Saccocia P, Craddock PR, Shanks WC III, Sylva SP, Walsh E, Pichler T, Rosner M (2011) Geochemistry of hydrothermal fluids from the PACMANUS, Northeast Pual and Vienna Woods hydrothermal fields, Manus Basin, Papua New Guinea. Geochim Cosmochim Acta 75:1088–1123CrossRefGoogle Scholar
  40. Schmidt K, Koschinsky A, Garbe-Schönberg D, Carvalho LM, Seifert R (2007) Geochemistry of hydrothermal fluids from the ultramafic-hosted Logatchev hydrothermal field, 15°N on the Mid-Atlantic Ridge: temporal and spatial investigation. Chem Geol 242:1–21CrossRefGoogle Scholar
  41. Seward TM, Williams-Jones AE, Migdisov AA (2014) The chemistry of metal transport and deposition by ore-forming hydrothermal fluids. In: Treatise on geochemistry 2nd edition.
  42. Seyfried WE Jr, Berndt M, Janecky DR (1986) Chloride depletions and enrichments in seafloor hydrothermal fluids: constraints from experimental basalt alteration studies. Geochim Cosmochim Acta 50:469–475CrossRefGoogle Scholar
  43. Seyfried WE Jr, Pester NJ, Ding K, Rough M (2011) Vent fluid chemistry of the Rainbow hydrothermal system (36°N, MAR): Phase equilibria and in situ pH controls on subseafloor alteration processes. Geochim Cosmochim Acta 75:1574–1593CrossRefGoogle Scholar
  44. Shmulovich K, Churakov SV (1998) Natural fluid phases at high temperatures and low pressures. J Geochem Expl 62:183–191CrossRefGoogle Scholar
  45. Simonson JM, Palmer DA (1993) Liquid-vapor partitioning of HCl,aq to 350 °C. Geochim Cosmochim Acta 57:1–7CrossRefGoogle Scholar
  46. Tagirov BR, Zotov AV, Akinfiev NN (1997) Experimental study of dissociation of HCl from 350 to 500 °C and from 500 to 2000 bars: thermodynamic properties of HCl°(aq). Geochim Cosmochim Acta 61:4267–4280CrossRefGoogle Scholar
  47. Tivey MK (2007) Generation of seafloor hydrothermal vent fluids and associated mineral deposits. Oceanogr 20:50–65CrossRefGoogle Scholar
  48. Vakulenko AG, Alekhin YuV, Rasina MV (1989) Solubility and thermodynamic properties of alkali chlorides in steam. Proc II Intern Sympos Properties of Water and Steam, Prague: 395–401Google Scholar
  49. Vanko DA, Bach W, Roberts S, Yeats CJ, Scott SD (2004) Fluid inclusion evidence for subsurface phase separation and variable fluid mixing regimes beneath the deep-sea PACMANUS hydrothermal field, Manus Basin back arc rift, Papua New Guinea. Journ Geophys Res 109: B03201, CrossRefGoogle Scholar
  50. VDI-Wärmeatlas (2006) 10th ed Springer, Berlin: 1512Google Scholar
  51. Von Damm KL (1990) Seafloor hydrothermal activity: black smoker chemistry and chimney. Ann Rev Earth Planet Sci Lett 18:173–204CrossRefGoogle Scholar
  52. Von Damm KL, Buttermore LG, Oosting SE, Bray AM, Fornari DJ, Lilley MD, Shanks WC III (1997) Direct observation of the evolution of a seafloor “black smoker” from vapor to brine. Earth Planet Sci Lett 149:101–112CrossRefGoogle Scholar
  53. Von Damm KL, Lilley MD, Shanks WC III, Brockington M, Bray AM, O’Grady KM, Olson E, Graham A, Proskurowski G, the SouEPR Science Party (2003) Extraordinary phase separation and segregation in vent fluids from the southern East Pacific Rise. Earth Planet Sci Lett 206:365–378CrossRefGoogle Scholar
  54. Walther J (1986) Experimental determination of portlandite and brucite solubilities in supercritical H2O. Geochim Cosmochim Acta 50:733–739CrossRefGoogle Scholar
  55. Yang KH, Scott SD (2005) Vigorous exsolution of volatiles in the magma chamber beneath a hydrothermal system on the modern sea floor of the eastern Manus back-arc basin, western Pacific: evidence from melt inclusions. Econ Geol 100th Anniv Vol: 1085–1096Google Scholar

Copyright information

© Springer-Verlag GmbH Germany, part of Springer Nature 2018

Authors and Affiliations

  • Chris Ballhaus
    • 1
    Email author
  • Fabian Gäb
    • 1
  • Dieter Garbe-Schönberg
    • 2
  • Michael Staubwasser
    • 3
  1. 1.Institut für Geowissenschaften und MeteorologieUniversität BonnBonnGermany
  2. 2.Institut für GeowissenschaftenUniversität KielKielGermany
  3. 3.Institut für Geologie und MineralogieUniversität zu KölnCologneGermany

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