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Physical Environment of Hydrothermal Systems in Iceland and on Submerged Oceanic Ridges

  • Valgardur Stefánsson
Chapter
Part of the NATO Conference Series book series (NATOCS, volume 12)

Abstract

The details of magmatic and hydrothermal activity are much better known in Iceland than at submerged rift zones. Therefore, it is of interest to compare hydrothermal system in Iceland and on other parts of mid-ocean ridges. The effect of topography on hy­drothermal systems for submarine systems is opposite to that of systems discharging into air. The reason for this is the simple fact that these two kinds of hydrothermal systems discharge into different kind of fluids as compared to the hydrothermal fluid. The working pressure of submarine hydrothermal systems is usually much higher than for systems on land. This fact, together with the higher salinity of the submarine systems, is most likely the cause of the metallic depositions observed on the sea floor. Downward penetration of cold water into hot rock is the only known process which can explain the high heat flux density of some hydrothermal systems in Iceland and it seems natural to assume that this process is of major importance for submarine systems. A controlled cooling experiment of hot lava during the Heimaey eruption of 1973 supports further that this process is a natural phenomenon. By comparing the heat flux through Iceland with the energy released on submarine spreading axes, it is found that neither the volcanic nor the hydrothermal activity in Iceland is exceptionally high as compared to estimates for submerged ridges. Extrapolation of knowledge of hydrothermal systems is therefore found to be realistic. In Iceland the cooling of the crust by hydrothermal and volcanic activity is concentrated to a certain location, the central volcanoes. The spacing of cooling spots in the Icelandic rift zones is approximately 12–15 km. This distance is approximately the same as the estimated thickness of the crust. It is proposed that the cooling of the submerged rift zones might proceed in a similar way and that the spacing of cooling spots is related to the spreading rate.

Keywords

Hydrothermal System Rift Zone Geothermal System Geothermal Field Central Volcano 
These keywords were added by machine and not by the authors. This process is experimental and the keywords may be updated as the learning algorithm improves.

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References

  1. Anderson, R. N., 1972, Petrologic significance of low heat flow on the flanks of slow spending midocean ridges, Geol. Soc. Am. Bull. 83 2947–2956, 1972.Google Scholar
  2. Anderson, R.N. and M.A. Hobart, 1976, The relation between heat flow, sediment thickness, and age in the Eastern Pacific, J. Geophys. Res. 81 2968–2989, 1976.Google Scholar
  3. Anderson, R. N., M. G., Langseth, and J. G. Sclater, 1977. The isms of heat transfer through the floor of the Indian Ocean. J. Geophys. Res. 82, 3391–3409.Google Scholar
  4. Anderson, R. N., 1979, Oceanic heat flow, In: The Sea, Vol. 7, pp 489–523 Wiley-Interscience, New York.Google Scholar
  5. Armannsson, H., G. Gislason, and T. Hauksson, 1982. Magmatic gases in well fluids aid the mapping of the flow pattern in a geothermal system. Geochim. Cosmochim. Acta 46, 167–177.Google Scholar
  6. Arnold, M., and S. M. F. Sheppard, 1981. East Pacific Rise at Latitude 21°N: isotopic composition and origin of the hydrothermal sulphur. Earth Planet. Sci. Lett. 56, 148–156Google Scholar
  7. Banwell, C. J., E. R. Cooper, G. E. K. Thompson, and K. J. McCree, 1957. Physics of the New Zealand thermal area. N.Z. Dept. Sci. and Indus. Research Bull. 123, 109 pp.Google Scholar
  8. Banwell, C. J., 1963. Thermal energy from the Earth’s crust; Introduction and part I, Natural hydrothermal systems. N.Z.J. Geol. Geophys. 6, 52–69.Google Scholar
  9. Beblo, M., and A. Bjornsson, 1978. Magnetotelluric investigation of the lower crust and upper mantle beneath Iceland. J. Geophys. 45, 1–16.Google Scholar
  10. Beblo, M., and A. Bjornsson, 1980. A model of electrical resistivity beneath NE-Iceland, correlation with temperature. J. Geophys. 47, 184–190.Google Scholar
  11. Bischoff, J. L., and F. W. Dickson, 1975. Seawater-basalt interaction at 200°C and 500 bars; Implications for origin of sea-floor heavy metal deposits and regulation of seawater chemistry. Earth Planet. Sci. Lett. 25, 385–397.Google Scholar
  12. Bischoff, J. L., and W. E. Seyfried, 1978. Hydrothermal chemistry of seawater from 25° to 350°C. American J. Sci. 278, 838–860.Google Scholar
  13. Bischoff, J. L., 1980. Geothermal system at 21°N, East Pacific Rise; Physical Limits on Geothermal fluid and role of adiabatic expansion. Science 207, 1465–1469.CrossRefGoogle Scholar
  14. Bjornsson, A., K. Saemundsson, P. Einarsson, E. Tryggvason, and K. Gronvold, 1977. Current rifting episode in North Iceland. Nature 266, 318–323.Google Scholar
  15. Bjornsson, A., G. Johnsen, S. Sigurdsson, and G. Thorbergsson, 1979. Rifting of the Plate Boundary in North Iceland 1975–1978. J. Geophys. Res. 84, 3029–3038.Google Scholar
  16. Bjornsson, H., 1974. Explanation of jokulhlaups from Grimsvotn, Vatnajokull, Iceland, Jokull 24, 1–26.Google Scholar
  17. Bjornsson, H., S. Bjornsson, and Th. Sigurgeirsson, 1982. Penetration of water into hot rock boundaries of magma in Grimsvotn, Nature 295, 580–581.Google Scholar
  18. Bodvarsson, G., 1951. Report on the Hengill thermal area, (in Icelandic with English summary), J. Engin. Assoc. Iceland, 36, 1–48.Google Scholar
  19. Bodvarsson, G., 1961. Physical Characteristics of Natural Heat Resources in Iceland. Jokull 11, 29–38.Google Scholar
  20. Bodvarsson, G., and R. P. Lowell, Ocean-floor heat flow and the circulation of interstitial waters. 1972, Ocean-floor heat flow and the circulation of interstitial waters. J. Geophys. Res. 77, 4472–4475.CrossRefGoogle Scholar
  21. Bodvarsson, G., 1979, Elastomechanical phenomena and the fluid conductivity of deep geothermal reservoirs and source regions. Workshop on Geothermal Reservoir Engineering, Dec. 1979, Stanford University, Stanford, California.Google Scholar
  22. Bodvarsson, G., 1982, Terrestrial energy currents and transfer in Iceland. In: Continental and Oceanic Rifts, ed. G. Palma-son, Geodynamics Series vol. 8, pp 271–282, AGU, Washington D C.CrossRefGoogle Scholar
  23. Bonatti, E., and Y. R. Naudu, 1965, The origin of manganese nodules on the ocean floor. American Journal of Science 263, 17–39.Google Scholar
  24. Bonatti, E., and O. Joensuu, 1966, Deep-sea iron deposit from the South Pacific. Science 154, 643–645Google Scholar
  25. Bonatti, E., 1975, Metallogenesis at oceanic spreading centers. Ann. Rev. Earth Planet. Sci. 3, 401–431Google Scholar
  26. Bonatti, E., 1978, The Origin of Metal Deposits in the Oceanic Lithosphere. Scientific American 238, 54–61Google Scholar
  27. Bostrom, K., and M. N. A. Petersen, 1966, Precipitates from hydrothermal exhalations on the East Pacific Rise. Econ Geology 61, 1258–1265.Google Scholar
  28. Bott, M. H. P., and K. Gunnarsson, 1980, Crustal structure of the Iceland-Faeroe Ridge, J. Geophys. 47, 221–227.Google Scholar
  29. Bottinga, Y., 1974, Thermal aspects of sea-floor spreading and the nature of the suboceanic lithosphere, Tectonophysics 21, 15–38Google Scholar
  30. Castillo B., F., F. J. Bermejo M., B. Domiquez A., C. A. Esquer P., Y. F. J. Navarro 0., 1981, Distribucion de temperatures en el campo geotermico de Cerro Prieto. Proceedings Third Synposium on the Cerro Prieto geothermal field, Baja California, Mexico, pp 474–483, Report LBL-11967.Google Scholar
  31. Corliss, J. B., 1971, The origin of Metal-Bearing Submarine Hydrothermal Solutions. J. Geophys. Res. 76, 8128–8138, 1971.Google Scholar
  32. Corliss, J. B., M. Lyle, J. Dymond, and K. Crane, 1978. The chemistry of hydrothermal mounds near the Galapagos rift. Earth Planet. Sci. Lett. 40, 12–24, 1978.Google Scholar
  33. Corliss, J. B., J. Dymond, L. I. Gordon, J. M. Edmond, R. P. Von Herzen, R. D. Ballard, K. Green, D. Williams, A. BainbridgeGoogle Scholar
  34. K. Crane, T. H. van Audel., 1979, Submarine thermal springs on the Galapagos Rift. Science 203, 1073–1083.Google Scholar
  35. Crane, K., and W. R. Normark, 1977, Hydrothermal activity and crestal structure of the East Pacific Rise at 21°N, J. Geophys. Res. 82, 5336–5348.Google Scholar
  36. Cronan, D. S., 1976, Implications of metal dispersion from submarine hydrothermal systems for mineral exploration on mid-ocean ridges and in island areas. Nature 262, 567–569.Google Scholar
  37. Cronan, D. S., G. P. Glasby, S. A. Moorby, J. Thomson, K. E. Knedler, and J. C. McDougall, 1982, A submarine hydrothermal manganese deposit from the south-west Pacific Island arc. Nature 298, 456–458.Google Scholar
  38. Cyamex Scientific Team, 1979, Nature 277, 523Google Scholar
  39. Davis, E. E., and C. R. B. Lister, 1974, Fundamentals of ridge crest topography. Earth Planet. Sci. Lett. 21, 405–413.Google Scholar
  40. Dunn, J. C., and H. C. Hardee, 1981, Superconvective geothermal zones. J. Volc. Geoth. Res. 11, 189–201, 1981.Google Scholar
  41. Dymond, J., J. B. Corliss, G. R. Heath, C. W. Field, E. J. Dasch, H. H. Veeh, 1973, Origin of Metalliferous Sediments from the Pacific Ocean. Geol. Soc. Am. Bull. 84, 3355–3372Google Scholar
  42. Edmond, J. M., C. Measures, R. E. McDuff, L. H. Chan, R. Collier, B. Grant, L. I. Gordon, and J. B. Corliss, 1979a. Ridge crest hydrothermal activity and the balances of the major and minor elements in the ocean; the Galapagos data. Earth Planet. Sci. Lett. 46, 1–18, 1979a.Google Scholar
  43. Edmond, J. M., C. Measures, B. Mangum, G. Grant, F. R. Sclater, R. Collier, A. Hudson, L. I. Gordon, and J. B. Corliss, 1979b, On the formation of metal-rich deposits at ridge crests. Earth Planet. Sci. Lett. 46, 19–30.Google Scholar
  44. Einarsson, P., 1978, Swave shadows in the Krafla caldera in NE-Iceland, evidence for a magma chamber in the crust. Bull. Volcanol. 41, 1–9, 1978.Google Scholar
  45. Einarsson, P., and B. Brandsdbttir, 1980, Seismological evidence for lateral magma intrusion during the July, 1978 deflation of the Krafla volcano in NE-Iceland. J. Geophys. 47, 160–165.Google Scholar
  46. Evans, J. R., and I. S. Sacks, 1979, Deep structure of the Iceland Plateau. J. Geophys. Res. 84, 6859–6866.Google Scholar
  47. Francheteau, J., H. D. Needham, P. Choakroune, T. Juteau, M. Séguret, R. D. Ballard, P. J. Fox, W. Normark, A. Carranza, D. CordobaGoogle Scholar
  48. J. Guerrero, C. Rangin, H. Bougault, P. Canbon, and R. Hekinian, 1979, Massive deep-sea sulphide ore deposits discovered on the East Pacific Rise. Nature 277, 523–528.Google Scholar
  49. Friedman, J. D., R. S. Williams Jr., S. Thorarinsson, and G. Pâlmason, 1972. Infrared emission from Kverkfjoll subglacial volcanic and geothermal area, Iceland. Jokull 22, 27–43.Google Scholar
  50. Fyfe, W. S. and P. Lonsdale, 1981. Submarine hydrothermal activity. In. C. Emiliani (ed) The Sea 7, Wiley-Interscience, New York, 589–638.Google Scholar
  51. Gebrande, H., H. Miller, and P. Einarsson, 1980, Seismic structure of Iceland along PRISP-profile I. J. Geophys. 47, 239–249.Google Scholar
  52. Green, K. E., R. P. von Herzen, and D. Williams, 1981, The Galapagos Spreading Center at 86°W: A detailed geothermal field study. J. Geoph. Res. 86, 979–986Google Scholar
  53. Hajash, A., 1975, Hydrothermal Processes along Mid-Ocean Ridges; An Experimental Investigation. Contrib. Mineral. Petrol. 53, 205–226.Google Scholar
  54. Haymon, R. M., and M. Kastner, 1981, Hot spring deposits on the East Pacific Rise at 21°N; preliminary description of mineralogy and genesis. Earth Planet. Sci. Lett. 53, 363–381.Google Scholar
  55. Heath, G. R., and J. Dymond, 1977, Genesis and transformation of metalliferous sediments from the East Pacific Rise, Bauer Deep, and Central Basin, northwest Nazca plate. Geol. Soc. Am. Bulletin 88, 723–733Google Scholar
  56. Hekinian, R., M. Fevrier, J. L. Bischoff, P. Picott, and W. C. Shanks, 1980, Sulfite deposits from the East Pacific Rise near 21°N. Science 207, 1433–1444.Google Scholar
  57. Henley, R. W., and A. McNabb, 1978, Magmatic vapor plumes and ground-water interaction in porphyry copper emplacement. Econ. Geol. 73, 1–20.Google Scholar
  58. Helgason, J., and M. Zentilli, 1982, Stratigraphy and correlation of the region surrounding the IRDP drill hole 1978, Reydarfjordur, Eastern Iceland. J. Geophys. Res. 87, 6405–6417.Google Scholar
  59. Hermance, J. F., 1981, Crustal genesis in Iceland; Geophysical constraints on crustal thickening with age. Geophys. Res. Lett. 8: 203–206.Google Scholar
  60. Hoffert, M., A. Perseil, R. Helkinian, P. Choukroune „ H. D. Needham, J. Francheteau, Y. Le Pichon, 1978, Hydrothermal deposits sampled by diving saucer in Transform Fault “A” near 37°N on the Mid-Atlantic Ridge, Famous area. Oceanol. Acta 1, 1., 73–86.Google Scholar
  61. Jenkins, W. J., J. M. Edmond, and J. B. Corliss, 1978, Excess 3He and He in Galapagos Submarine hydrothermal waters. Nature 272, 156–158.Google Scholar
  62. Jonsson, V. K., and M. Matthiasson, 1974, Cooling the Heimaey lava with water - Report on the operation (in Icelandic). J. Engin. Assoc. Iceland 59, 70–83.Google Scholar
  63. Lister, C. R. B., 1972, On the Thermal Balance of a Mid-Ocean Ridge. Geophys. J. R. astr. Soc. 26, 515–535.Google Scholar
  64. Lister, C. R. B., 1974, On the Penetration of water into hot rock. Geophys. J. R. astr. Soc. 39, 465–509.Google Scholar
  65. Lister, C. R. B., 1976, Qualitative theory on the deep end of geothermal systems. U.N. Symp. Development and Use Geothermal Resources, 2nd 1975, Proc. 1, 459–463.Google Scholar
  66. Lister, C. R. B., 1977a, Qualitative models of spreading-center processes, including hydrothermal penetration. Tectonophysics 37, 203–218.Google Scholar
  67. Lister, C. R. B., 1977b, Estimators for heat flow and deep rock properties based on boundary-layer theory. Tectonophysics 41, 157–171.Google Scholar
  68. Lister, C. R. B., 1980, Heat flow and hydrothermal circulation. Ann. Rev. Earth. Planet. 8, 95–117.Google Scholar
  69. Lister, C. R. B., 1982, “Active” and “Passive” Hydrothermal Systems in the Oceanic Crust; Predicted Physical Conditions. In: The Dynamic Environment of the Ocean Floor, K. A. Fanning and F. T. Manheim Eds, pp 441–470, Lexington, Mass.Google Scholar
  70. Lonsdale, P. F., J. L. Bischoff, V. M. Burns, M. Kastner, and R. E. Sweenly, 1980, A high-temperature hydrothermal deposit on the seabed at a Gulf of California Spreading Center. Earth Planet. Sci. Lett. 49, 8–20.Google Scholar
  71. Lowell, R. P., 1980, Topographically driven subcritical hydrothermal convection in the oceanic crust. Earth Planet. Sci. Lett. 49, 21–28.Google Scholar
  72. MacDonald, K. C., K. Becker, F. N. Spiess, and R. D. Ballard, 1980. Hydrothermal heat flux of the “black smoker” vents on theGoogle Scholar
  73. East Pacific Rise. Earth Planet. Sci. Lett. 48, 1–7.Google Scholar
  74. Mottl, M. J., and H. D. Holland, 1978, Chemical exchange during hydrothermal alteration of basalt by seawater - I. Experimental results for major and minor components of seawater. Geochim, Cosmochim. Acta 42, 1103–1115.Google Scholar
  75. Mottl, M. J., H. D. Holland, and R. F. Corr, 1979, Chemical exchange during hydrothermal alteration of basalt by seawater - II. Experimental results. for Fe, Mn, and sulfur species. Geochim. Cosmochim. Acta 43, 869–884, 1979.Google Scholar
  76. Muehlenbachs, K., and R. N. Clayton, 1972, Oxygen isotope geochemistry of submarine greenstones. Can. J. Earth Sci. 9, 471–478, 1972.Google Scholar
  77. Muffler, L. J. P., and D. E. White, 1969, Active metamorphism of Upper Cenozoic sediments in the Salton Sea geothermal field and the Salton Trough, Southeastern California. Geol. Soc. Am. Bull. 80, 157–182.Google Scholar
  78. Oudin, E., P. Picot, and G. Pouit, 1981, Comparison of sulphide deposits from the East Pacific Rise and Cyprus. Nature 291, 404–407.Google Scholar
  79. Palmason, G., 1981, Crustal structure of Iceland from explosion seismology. Soc. Sci. Islandica 40, 187 pp, 1971. Parker, R.L., and D.W. Oldenburg, 1973, Thermal model of ocean ridges. Nature 242, 137–139.Google Scholar
  80. Reyss, J. L., V. Marchig, and T. L. Ku, 1982, Rapid growth of a deep-sea manganese nodule. Nature 295, 401–403.Google Scholar
  81. Robinson, P. T., J. M. Hall, N. I. Christensen, I. L. Gibson, I. Fridleifsson, H.-U. Schmincke, and G. Schonharting. 1982, The Iceland Research Drilling Project: Syntheses of results and implications for the nature of Icelandic and oceanic crust. J. Geophys. Res. 87, 6657–6667.Google Scholar
  82. Rona, P. A., 1976, Pattern of hydrothermal mineral deposition; mid-Atlantic Ridge crest at latitude 26°N. Marine Geology 21, 59–66.Google Scholar
  83. Rona, P. A., R. N. Harbison, B. G. Bassinger, R. B. Scott, and A. J. Natwalk, 1976, Tectonic fabric and hydrothermal activity of mid-Atlantic Ridge crest (lat. 26N). Geol. Soc. Am. Bull. 87, 661–674.Google Scholar
  84. Rona, P. A., 1980, TAG Hydrothermal field; Mid-Atlantic Ridge crest at latitude 26N. J. Geol. Soc. London 137, 385–402.Google Scholar
  85. Sanford, A. R., and P. Einarsson, 1982, Magma chambers in rifts. In: Continental and Oceanic Rifts, ed. G. Palmason; pp 147–168, AGU, Washington D.C.CrossRefGoogle Scholar
  86. Sclater, J. G., and J. Francheteau, 1970, The implications of terrestrial heat flow observations on current tectonic and geochemical models of the crust and upper mantle of the earth. Geophys. J. R. astr. Soc., 20, 509–542.Google Scholar
  87. Sclater, J. G., R. N. Anderson, and M. L. Bell, 1971, The evaluation of the central eastern Pacific. J. Geophys. Res. 76, 7888–7915.Google Scholar
  88. Sclater, J. G., R. P. Von Herzen, D. L. Williams, R. N. Anderson, and K. Klitgord, 1974, The Galapagos Spreading Centre; Heat-flow low on the North Flank. Geophys. J.R. astr. Soc. 38, 609–626.Google Scholar
  89. Sclater, J. G., C. Jauport, and D. Galson, 1980, The heat flow through oceanic and continental crust and the heat loss of the Earth. Rev. Geoph. Space Phys. 18, 269–311.Google Scholar
  90. Scott, R. B., P.A. Rona, B. A. McGregor, and M. R. Scott, 1974, The TAG hydrothermal field. Nature 251, 301–302.CrossRefGoogle Scholar
  91. Scott, R. B., J. Malpas, P. A. Rona, and G. Udintsev, 1976. Duration of hydrothermal activity at an oceanic spreading center, Mid-Atlantic Ridge (lat$126°N). Geology 4, 233–236.CrossRefGoogle Scholar
  92. Seyfried, W. G., and M. J. Mottl, 1977, Origin of submarine metalrich hydrothermal solution: Experimental basalt-seawater interaction in a seawater-dominated system at 300°C, 500 bars. Proc. 2nd Int. Sympos. Water-Rock Interaction, IAGC Strassbourg, France, pp IV 173 - IV 180.Google Scholar
  93. Seyfried, W., and J. L. Bischoff, 1977, Hydrothermal transport of heavy metals by seawater; The role of seawater/basalt ratio. Earth Planet. Sci. Lett. 34, 71–77.Google Scholar
  94. Seyfried, W. E., Jr., and J. L. Bischoff, 1981, Experimental seawater-basalt interaction at 300C, 500 bars, chemical exchange, secondary mineral formation and implications for the transport of heavy metals. Geochim. Cosmochim. Acta 45, 135–147.Google Scholar
  95. Seyfried, W. E., and M. J. Mottl, 1982, Hydrothermal alteration of basalt by seawater under seawater-dominated conditions. Geochim. Cosmochim. Acta 46, 985–1002.Google Scholar
  96. Shanks, W. C., and J. L. Bischoff, 1977, Ore transport and deposition in the Red Sea geothermal system; a geochemical model; Geochim. et Cosmochim. Acta 41, 1507–1509.Google Scholar
  97. Sigurdsson, H., and R. S. J. Sparks, 1978, Lateral magma flow within rifted Icelandic crust. Nature 274, 126–130.Google Scholar
  98. Skornyakova, I. S., 1965, Dispersed iron and manganese in Pacific Ocean Sediments. International Geology Review 7: 2161–2174.CrossRefGoogle Scholar
  99. Sleep, N. H., and T. J. Wolery, 1978, Egress of hot water from midocean ridge hydrothermal systems: Some thermal constrains. J. Geophys. Res. 83, 5913–5922.Google Scholar
  100. Sourirajan, S., and G. C. Kennedy, The system H2O-NaCl at elevated temperatures and pressures. Am. J. Sci. 260, 115–141.Google Scholar
  101. Spiess, F. N., K. C. Mcdonald, T. Atwater, R. Ballard, A. Carranza, D. Cordoba, C. Cox, M. Draz Garcia, J. Francheteau, J. Guerrero, J. Hawkins, R. Haymon, R. Hessler, T. Juteau, M. Kastner, R. Larson, B. Luyendyk, J. D. Macdougall, S. Miller, W. Normark, J. Orcutt, C. Rangin, 1980, East Pacific Rise; Hot Springs and Geophysical Experiments. Science 207, 1421–1433.Google Scholar
  102. Spooner, E. T. C., and W. S. Fyfe, 1973, Sub-sea floor metamorphism, heat and mass transfer. Contrib. Mineral. Petrol. 42, 278–303.Google Scholar
  103. StefAnsson, V., 1981, The Krafla Geothermal Field, Northeast Iceland. In: Geothermal Systems, Principles and Case Histories, ed. StefAnsson, V., pp. 273–294, John Wiley and Sons.Google Scholar
  104. Strauss, J. M., and G. Schubert, 1977, Thermal convection of water in a porous medium: Effects of temperature - and pressure - dependent thermodynamic and transport properties. J. Geophys. Res. 82, 325–333.Google Scholar
  105. Styrt, M. M., A. J. Brackmann, H. D. Holland, B. C. Clark, V. Pisutha-Arnold, C. S. Eldridge, and H. Ohmoto, 1981, The mineralogy and the isotopic composition of sulfur in hydrothermal sulfide/sulfate deposits on the East Pacific Rise, 21N latitude. Earth Planet. Sci. Lett. 53, 382–390.Google Scholar
  106. Swanson, D. A., W. A. Duffield, and R. S. Fiske, 1976, Displacement of the south flank of Kilauea Volcano: The result of forceful intrusion of magma into the rift zones. U.S. Geol. Survey Prof. Paper 963 1–39.Google Scholar
  107. Talwani, M., X. Le Pichon, and M. Ewing, 1965, Crustal structure of the mid-ocean ridges. 2. Computed model from gravity and seismic refraction data. J. Geophys. Res. 70, 341–352, 1965.Google Scholar
  108. Thayer, R. E., A. Bjornsson, L. Alvarex, and J. F. Hermance, 1981, Magma genesis and crustal spreading in the northern neovolcanic zone of Iceland. Telluric-magnetotelluric constrains. J. Geophys. Res. astr. Soc. 65: 423–442.Google Scholar
  109. Vogt, P. R., 1974, Volcano spacing, fractures, and thickness of the lithosphere. Earth Planet. Sci. Lett. 21, 235–252.Google Scholar
  110. Weiss, R. F., P. Lonsdale, J.E. Lupton, A. E. Bainbridge, H. Craig. 1977, Hydrothermal plumes in the Galapagos Rift. Nature 267, 600–603.Google Scholar
  111. White, D. E., 1957, Thermal waters of volcanic origin. Bull. Geol. Soc. Am. 68, 1637–1657.Google Scholar
  112. White, D. E., 1968, Hydrology, activity, and heat flow of the steamboat springs thermal system, Washoe County, Nevada. U.S.G.S. Prof. Paper 458 - C 109 p.Google Scholar
  113. Williams, D. L., Von Herzen, R. P., J. G. Sclater, and R. N. Anderson, 1974. The Galapagos Spreading Center and hydrothermal circulation. Geophys. J. R. astr., Soc. 38, 587–608.Google Scholar
  114. Williams, D. L., K. Green, T. H. van Andel, R. P. Von Herzen, J. R. Dymond, and K. Crane, 1979, The hydrothermal mounds of the Galapagos Rift; Observations with DSRV Alvin and detailed heat flow studies. J. Geophys. Res. 84, 7467–7484.Google Scholar

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© Springer Science+Business Media New York 1983

Authors and Affiliations

  • Valgardur Stefánsson
    • 1
  1. 1.ORKUSTOFNUN108 ReykjavikIceland

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