FastFind »   Lastname: doi:10.1029/ Year: Advanced Search  

Geophysical Monograph Series



  • Hydrothermal vents—Congresses
  • Hydrothermal deposits—Congresses
  • Hydrothermal vent ecology—Congresses

Index Terms

  • 8135 Tectonophysics: Hydrothermal systems
  • 3660 Mineralogy and Petrology: Metamorphic petrology
  • 4825 Oceanography: Biological and Chemical: Geochemistry
  • 3035 Marine Geology and Geophysics: Midocean ridge processes



Subseafloor processes in mid-ocean ridge hydrothennal systems

J. C. Alt

Convective circulation of seawater through oceanic crust at mid-ocean ridges (MOR) and on ridge flanks has wide-ranging effects on heat transport, the chemical and isotopic compositions of ocean crust and seawater, mineralization of the crust, and on the physical properties of oceanic basement. Submarine hydrothermal systems remove about 30% of the heat lost from oceanic crust [Selater et al., 1981; Stein and Stein, 1994], and chemical and isotopic exchange between seawater and basement rocks exerts important controls on the composition of seawater [Edmond et al., 1979a; Thompson, 1983]. The composition of altered crust is also changed and, when subducted, this altered crust can contribute to chemical and isotopic heterogeneities in the mantle [Zindler and Hart, 1986] and may affect the compositions of volcanic rocks in island arcs [Perfit et al., 1980; Tatsumi, 1989]. Mineralization of ocean crust occurs where metals, leached from large volumes of altered crust at depth, are concentrated at or near the surface by hydrothermal circulation [Hannington, 1995]. Hydrothermal alteration of magnetic minerals may affect the source of marine magnetic anomalies [Pariso and Johnson, 1991], and the formation of secondary minerals influences the density, porosity, and seismic velocity structure of the crust [Wilkens et al., 1991; Jacobson, 1992].

Citation: Alt, J. C. (1995), Subseafloor processes in mid-ocean ridge hydrothennal systems, in Seafloor Hydrothermal Systems: Physical, Chemical, Biological, and Geological Interactions, Geophys. Monogr. Ser., vol. 91, edited by S. E. Humphris et al., pp. 85–114, AGU, Washington, D. C., doi:10.1029/GM091p0085.

Cited By

Please wait one moment ...