Abstract
Recent seismic studies along the northern East Pacific Rise have documented the existence of a thin, narrow crustal magma body that is significantly smaller than the magma chambers incorporated into many earlier ridge crest geological models. The predominately molten part of the chamber is only 1–2 km wide and less than a kilometer thick, although it can extend as a nearly continuous feature for distances of several kilometers to several tens of kilometers along the ridge crest. This thin, sill-like body of melt is surrounded by a much wider zone of anomalously low seismic velocities that is interpreted as ranging from a partially molten crystal mush to the solidified (but still hot) plutonic rocks of the lower oceanic crust. This magma-sill model of a mid-ocean ridge magma chamber has important implications for the petrological and geochemical variability of mid-ocean ridge basalts and the origin of the thick cumulate sections found in ophiolites.
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References
Brandeis, G. and C. Jaupart, 1986. On the interaction between convection and crystallization in cooling magma chambers, Earth. Planet. Sci. Lett., 86: 345–361.
Browning, P., 1984. Cryptic variation within the cumulate sequence of the Oman ophiolite: magma chamber depth and petrological implications. In: I.G. Gass, S.J. Lippard and A.W. Shelton (Ed.), Ophiolites and Oceanic Lithosphere, Geol. Soc. London Spec. Publ., 13: 71–82.
Bryan, W.B. and J.G. Moore, 1977. Compositional variations of young basalts in the Mid-Atlantic Ridge rift valley near lat. 36°49’N, Geol. Soc. Am. Bull., 88: 556–570.
Burnett, M.S., Caress, D.W. and J.A. Orcutt, 1989. Tomographie image of the magma chamber at 12°50’N on the East Pacific Rise, Nature, 339: 206–208.
Cann, J.R., 1974. A model for oceanic crustal structure developed, Geophys. J.R. astron. Soc., 39: 169–187.
Caress, D., Burnett, M. and J. Orcutt, in press. Tomographic image of the axial low velocity zone at 12°50’N on the East Pacific Rise, J. Geophys. Res.
Collier, J. and M. Sinha, 1990. Seismic images of a magma chamber beneath the Lau Basin back-arc spreading centre, Nature, 346: 646–648.
Detrick, R.S., Buhl, P., Vera, E., Mutter, J., Orcutt, J., Madsen, J. and T. Brocher, 1987. Multichannel seismic imaging of a crustal magma chamber along the East Pacific Rise, Nature, 326: 35–41.
Dewey, J.F. and W.S.F. Kidd, 1977. Geometry of plate accretion, Geol. Soc. Soc. Am., 88: 960–9687.
Hale, L.D., Morton, C.J. and N.H. Sleep, 1982. Reinterpretation of seismic reflection data over the East Pacific Rise, J. Geophys. Res., 87: 7707–7717.
Harding, A.J., Orcutt, J., Kappus, M., Vera, E., Mutter, J., Buhl, P., Detrick, R. and T. Brocher, 1989. The structure of young oceanic crust at 13°N on the East Pacific Rise from Expanding Spread Profiles, J. Geophys. Res., 94: 12,163–12,196.
Herron, T.J., Ludwig, W.J., Stoffa, P.L., Kan, T.K., and P. Buhl, 1978. Structure of the East Pacific Rise from multichannel seismic reflection data, J. Geophys. Res., 83: 798–804.
Herron, T.J., Stoffa, P.L. and P. Buhl, 1980. Magma chamber and mantle reflections – East Pacific Rise, Geophys. Res. Lett., 7: 989–992.
Huppert, H.E. and R.S.J. Sparks, 1980. The fluid dynamics of a basaltic magma chamber replenished by influx of hot, dense ultrabasic magma, Contrib. Mineral. Petrol., 75: 279–289.
Huppert, H.E. and J.S. Turner, 1981. A laboratory model of replenished magma chamber, Earth Planet. Sci. Lett., 54: 144–152.
Irvine, T.N., Keith, D.W. and S.G. Todd, 1983. The J-M platinum-palladium reef on the Stillwater complex, Montana: II. Origin by double-diffusive convective magma mixing and implications for the Bushveld complex, Bull. Soc. Econ. Geol., 78: 1287–1334.
Kent, G.M., Harding, A.J. and J.A. Orcutt, 1990. Evidence for a smaller magma chamber beneath the East Pacific Rise at 9°30’N, Nature, 344: 650–653.
Kim, I. and J.A. Orcutt, 1989. Effects of disrupted axial morphology on the amplitude strength of the crustal magma chamber reflection at the East Pacific Rise, EOS, (Trans. Am. Geophys. Union), 70: 1317.
Klitgord, K.D. and J. Mammerickx, 1982. Northern East Pacific Rise: Magnetic anomaly and bathymetric framework, J. Geophys. Res., 87: 6725–6750.
Langmuir, C.H., 1989. Geochemical consequences of in situ crystallization, Nature, 340: 199–205.
Langmuir, C.H., Bender, J.F. and R. Batiza, 1986. Petrologic and tectonic segmentation of the East Pacific Rise, 5°30’-14°30’N, Nature, 322: 422–426.
Lewis, B.T.R., 1983. The process of formation of ocean crust, Science, 220: 151–157.
Lewis, B.T.R. and J.D. Garmany, 1982. Constraints on the structure of the East Pacific Rise from seismic refraction data, J. Geophys. Res., 87: 8,417–8,425.
Macdonald, K.C., 1989. Anatomy of the magma reservoir, Nature, 339: 178–179.
Macdonald, K.C., 1982. Mid-ocean ridges: Fine scale tectonic, volcanic and hydrothermal processes within the plate boundary zone, Ann. Rev. Earth Planet. Sci., 10: 155–190.
Macdonald, K.C. and P.J. Fox, 1988. The axial summit graben and cross-sectional shape of the East Pacific Rise as indicators of axial magma chambers and recent volcanic eruptions, Earth Planet. Sci. Lett., 88: 119–131.
Madsen, J.A., Detrick, R.S., Mutter, J.C., Buhl, P. and J.C. Orcutt, 1990. A two-and three-dimensional analysis of gravity anomalies associated with the East Pacific Rise at 9°N and 13°N, J. Geophys. Res., 95: 4967–4987.
Manghnani, M.H., Sato, H. and C.S. Rai, 1986. Ultrasonic velocity and attenuation measurements on basalt melts to 1500°C: Role of composition and structure in the viscoelastic properties, J. Geophys. Res., 91: 9333–9342.
McBirney, A.R. and R.M. Noyes, 1979. Crystallization and layering of the Skaergaard intrusion, J. Petrol., 20: 487–554.
McClain, J.S., Orcutt, J.A. and M. Burnett, 1985. The East Pacific Rise in Cross-Section: A Seismic Model, J. Geophys. Res., 90: 8627–8640.
Morton, J.L. and N. Sleep, 1985. Seismic reflections from a Lau Basin magma chamber, in Scholl, D.W. and Vallier, T.L., eds., Geology and offshore resources of Pacific island arcs - Tonga region, Circum-Pacific Council for Energy and Mineral Resources Earth Science Series, v. 2: Houston Texas, 441–453.
Murase, T. and A. McBirney, 1973. Properties of Some Common Igneous Rocks and Their Melts at High Temperatures, Geol. Soc. Amer. Bull., 84: 3563–3592.
Mutter, J.C., Barth, G.A., Buhl, P., Detrick, R.S., Orcutt, J. and A. Harding, 1988. Magma distribution across ridge-axis discontinuities on the East Pacific Rise from multichannel seismic images, Nature, 336: 156–158.’
Nicolas, A., 1989. Structures of Ophiolites and Dynamics of Oceanic Lithosphere. Kluwer, Dordrecht, 367 pp.
Nicolas, A., Reuber, I. and K. Benn, 1988. A new magma chamber model based on structural studies in the Oman ophiolite, Tectonophysics, 151: 87–105.
Orcutt, J.A., Kennett, B.L.N, Dorman, L.M and W. Prothero, 1975. A low velocity zone underlying a fast spreading ridge crest, Nature, 256: 475–476.
Pallister, J.S. and C.A. Hopson, 1981. Samail ophiolite plutonic suite: field relations, phase variation, cryptic variation and layering and a model of a spreading ridge magma chamber, J. Geophys. Res., 86: 2593–2644.
Rosendahl, B.R., Raitt, R.W., Dorman, L.M., Bibee, L.D., Hussong, D.M. and G.H. Sutton, 1976. Evolution of oceanic crust: 1. A physical model of the East Pacific Rise crest derived from seismic refraction data, J. Geophys. Res., 81: 5294–5304.
Sinton, J.M., Smaglik, S.M., and J.J. Mahoney, 1988. Along-axis magmatic variations at super-fast spreading: East Pacific Rise, 13–23°S, EOS (Trans. Am. Geophys. Union), 69: 1473.
Sinton, J.M., Smaglik, S.M., Mahoney, J.J. and K.C. Macdonald, 1991. Magmatic processes at superfast spreading oceanic ridges: Glass compositional variations along the East Pacific Rise 13°-23°S, J. Geophys. Res., 96: 6133–6155.
Toomey, D.R., Purdy, G.M., Solomon, S.C. and W.S.D. Wilcock, 1990. The three-dimensional seismic velocity structure of the East Pacific Rise near latitude 9°30’N, Nature, 347: 639–645.
Vera, E.E., Buhl, P., Mutter, J.C., Harding, A.J., Orcutt, J.A. and R.S. Detrick, 1990. The structure of 0–0.2 My old oceanic crust at 9°N in the East Pacific Rise from expanded spread profiles, J. Geophys. Res., 95: 15,529–15,556.
Usselman, T.M. and D.S. Hodge, 1978. Thermal central of low pressure fractionation processes, J. Volcanol. geotherm. Res., 4: 265–281.
Wilson, D.S., Clague, D.A., Sleep, N.H. and J. Morton, 1988. A model for narrow, steady state magma chambers on fast spreading ridges, J. Geophys. Res., 93: 11,974–11,984.
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Detrick, R.S. (1991). Ridge Crest Magma Chambers: A Review of Results from Marine Seismic Experiments at the East Pacific Rise. In: Peters, T., Nicolas, A., Coleman, R.G. (eds) Ophiolite Genesis and Evolution of the Oceanic Lithosphere. Petrology and Structural Geology, vol 5. Springer, Dordrecht. https://doi.org/10.1007/978-94-011-3358-6_2
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DOI: https://doi.org/10.1007/978-94-011-3358-6_2
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