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Q structure of the oceanic crust

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Abstract

Compressional wave attenuations and velocities have been measured as a function of confining pressure in ophiolite samples representing a cross-section of the oceanic crust and uppermost mantle. Data are presented for basalts, diabase dikes, gabbros and a suite of serpentinites and peridotites showing a range of serpentization. An ultrasonic pulse-echo spectral ratio technique was used to determine the attenuations to confining pressures of 500 MPa. From this data a Q profile for the oceanic crust and upper mantle is presented. Q is found to moderately increase with depth through the pillow basalts of the upper oceanic crust. The sheeted dike rocks of Layer 2C show an increase in Q with depth due to progressive metamorphism (from greenschist to amphibolite facies). Q drops abruptly from Layer 2C to Layer 3, though it is not clear why the gabbros have such low Q's. The crust-mantle boundary is a Q discontinuity; however, the Q contrast between Layer 3 and the upper mantle could be altered by upper mantle serpentinization, interlayered gabbros and peridotites at the boundary, or serpentinized peridotite diapirs intruding the gabbroic section. Q varies significantly with the percentage of serpentinization in the ultramafic samples, with the largest changes in Q being at the extremes of zero and full serpentinization. Q is sensitive to the overburden pressure for all of the samples.

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References

  • Birch, F., 1960, The Velocity of Compressional Waves in Rocks to 10 Kilobars, Part 1. J. Geophys. Res. 65, 1083–1102.

    Google Scholar 

  • Birch, F., 1961, The Velocity of Compressional Waves in Rocks to 10 Kilobars, Part 2, J. Geophys. Res. 66, 2199–2224.

    Google Scholar 

  • Birch, F. and Bancroft, D., 1938a, The Effect of Pressure on the Rigidity of Rocks, I, J. Geol. 46, 59–87.

    Google Scholar 

  • Birch, F. and Bancroft, D., 1938b, The Effect of Pressure on the Rigidity of Rocks, II, J. Geol. 46, 113–141.

    Google Scholar 

  • Bonatti, E. and Honnorez, J., 1976. Sections of the Earth's Crust in the Equatorial Atlantic, J. Geophys. Res. 81, 4104–4116.

    Google Scholar 

  • Born, W. T., 1941, The Attenuation Constant of Earth Materials, Geophysics 6, 132–148.

    Google Scholar 

  • Bowman, J. R., 1988, Body Wave Attenuation in the Tonga Subduction Zone, J. Geophys. Res. 93, 2125–2139.

    Google Scholar 

  • Cann, J. R., 1968, Geological Processes at Mid-Ocean Ridge Crests, Geophys. J. R. Astr. Soc. 15, 333–341.

    Google Scholar 

  • Christensen, N. I., 1966, Elasticity of Ultrabasic Rocks. J. Geophys. Res. 71, 5921–5931.

    Google Scholar 

  • Christensen, N. I., 1972, The Abundance of Serpentinites in the Oceanic Crust, J. Geol. 80, 709–719.

    Google Scholar 

  • Christensen, N. I., 1985, Measurements of Dynamic Properties of Rock at Elevated Temperatures and Pressures, in PincusH. J. and HoskinsE. R. (eds.), Measurement of Rock Properties at Elevated Pressures and Temperatures, ASTM STP 869, American Society for Testing and Materials, Philadelphia, 93–107.

    Google Scholar 

  • Christensen, N. I. and Salisbury, M. H., 1982, Lateral Heterogeneity in the Seismic Structure of the Ocean Crust Inferred from Velocity Studies in the Bay of Islands, Ophiolite, Newfoundland, Geophys. J. R. Astr. Soc. 68, 675–688.

    Google Scholar 

  • Christensen, N. I. and Smewing, J. D., 1981, Geology and Seismic Structure of the Northern Section of the Oman Ophiolite, J. Geophys. Res. 86, 2545–2555.

    Google Scholar 

  • Clague, D. A. and Straley, P. F., 1977, Petrologic Nature of the Oceanic Moho, Geology 5, 133–136.

    Google Scholar 

  • Clark, V. A., Tittmann, B. R., and Spencer, T. W., 1980, Effect of Volatiles on Attenuation (1/Q) and Velocity in Sedimentary Rocks, J. Geophys. Res. 85, 5190–5198.

    Google Scholar 

  • Coleman, R. G., 1977, Ophiolites: Ancient Oceanic Lithosphere? WyllieP. J., vonEngelhardtW. and HahnT. (eds.), Minerals and Rocks 12, Springer-Verlag, Germany.

    Google Scholar 

  • Collins, J. A., Brocher, T. M., and Karson, J. A., 1986. Two-Dimensional Seismic Reflection Modeling of the Inferred Fossil Oceanic Crust/Mantle Transition in the Bay of Islands Ophiolite, J. Geophys. Res. 91, 12520–12538.

    Google Scholar 

  • Crosson, R. S. and Lin, J. W., 1971, Voight and Reuss Prediction of Anisotropic Elasticity of Dunite, J. Geophys. Res. 76, 570–578.

    Google Scholar 

  • Dietz, R. S., 1963, Alpine Serpentines as Oceanic Rind Fragments, Bull. GSA 74, 947–952.

    Google Scholar 

  • Francis, T. J. G., 1981, Serpentinization Faults and their Role in the Tectonics of Slow Spreading Ridges, J. Geophys. Res. 86, 11616–11622.

    Google Scholar 

  • Frisillo, A. L. and Stewart, T. J., 1980, Effect of Parital Gas/Brine Saturation on Ultrasonic Absorption in Sandstone, J. Geophys. Res. 85, 5209–5211.

    Google Scholar 

  • Futterman, W. I., 1962, Dispersive Body Waves, J. Geophys. Res. 67, 5257–5291.

    Google Scholar 

  • Gardner, G. H. F., Wyllie, M. P. J. and Droschak, D. M., 1964, Effects of Pressure and Fluid Saturation on the Attenuation of Elastic Waves in Sands, J. Pet. Tech. 16, 189–198.

    Google Scholar 

  • Hess, H. H., 1962, History of Ocean Basins, in Engel, A. E. J. (ed.), Petrologic Studies: A volume to honor A. F. Buddington, Bull GSA 599–620.

  • Houtz, R. and Ewing, J., 1976, Upper Crustal Structure as a Function of Plate Age, J. Geophys. Res. 81, 2490–2498.

    Google Scholar 

  • Hyndman, R. D. and Drury, M. J., 1976. The Physical Properties of Oceanic Basement Rocks from Deep Sea Drilling on the Mid-Atlantic ridge, J. Geophys. Res. 81, 4042–4059.

    Google Scholar 

  • Jacobson, R. S. and Lewis, B. T. R., 1988, Attenuation Results from the Uppermost Young Oceanic Crust, EOS, Trans. Am. Geophys. Un. 69, 406.

    Google Scholar 

  • Johnston, D. H., 1981, Attenuation: A State-of-the-Art Summary, in Johnston, D. H. and Toksoz, M. N. (eds.), Seismic Wave Attenuation, SEG Geophys. Reprint Ser. No. 2, Tulsa, 123–135.

  • Johnston, D. H. and Toksoz, M. N., 1980, Ultrasonic P and S Wave Attenuation in Dry and Saturated Rocks under Pressure, J. Geophys. Res. 85, 925–936.

    Google Scholar 

  • Johnston, D. H. and Toksoz M. N., 1981, Definitions and Terminology, in Johnston, D. H. and Toksoz, M. N. (eds.), Seismic Wave Attenuation, SEG Geophys. Reprint Ser. No. 2, Tulsa, 1–5.

  • Kempner, W. C. and Gettrust, J. F., 1982, Ophiolites, Synthetic Scismograms and Ocean Crustal Structure 1. Comparison of Ocean Bottom seismometer Data and Synthetic Seismograms for the Bay of Islands Ophiolite, J. Geophys. Res. 87, 8447–8462.

    Google Scholar 

  • Kirkpatrick, R. J., 1979, The Physical State of the Oceanic Crust: Results of Downhole Geophysical Logging in the Mid-Atlantic Ridge at 23 oN, J. Geophys. Res. 84, 178–188.

    Google Scholar 

  • Kjartansson, E., 1979, Constant Q-Wave Propagation and Attenuation, J. Geophys. Res. 84, 4737–4748.

    Google Scholar 

  • Mason, M. P., 1969, Internal Friction Mechanism that Produces an Attenuation in the Earth's Crust Proportional to the Frequency, J. Geophys. Res. 74, 4963–4966.

    Google Scholar 

  • Mason, W. P. and Kuo, J. T., 1971, Internal Friction of Pennsylvania Slate, J. Geophys. Res. 76, 2084–2089.

    Google Scholar 

  • Mason, W. P., Marfurt, K. J., Beshers, D. N., and Kuo, J. T., 1978, Internal Friction in Rocks, J. Acoust. Soc. Am. 63, 1596–1603.

    Google Scholar 

  • Murphy, W. F.III, 1982, Effects of Partial Water Saturation on Attenuation in Massilon Sandstone and Vycor Porous Glass, J. Acous. Soc. Am. 71, 1458–1468.

    Google Scholar 

  • Oliver, J. and Isacks, B., 1967, Deep Earthquakes Zones, Anomalous Structures in the Upper Mantle, and the Lithosphere, J. Geophys. Res. 72, 4259–4275.

    Google Scholar 

  • Orcutt, J., Kennett, B., Dorman, L., and Prothero, W., 1975, Low Velocity Zone Underlying Fast-spreading Rise Crest, Nature 256, 475–476.

    Google Scholar 

  • Pallister, J. D., 1981, Structure of the Sheeted Dike Complex of the Samail Ophiolite near Ibra, Oman, J. Geophys. Res. 86, 2661–2672.

    Google Scholar 

  • Raitt, R. W., 1963, The Crustal Rock, in HillM. N. (ed.), The Sea, 3, Interscience, New York, 85–102.

    Google Scholar 

  • Salisbury, M. H. and Christensen, N. I., 1978, The seismic Velocity Structure of a Traverse Through the Bay of Islands Ophiolite Complex, Newfoundland, an Exposure of Oceanic Crust and Upper Mantle, J. Geophys. Res. 83, 805–817.

    Google Scholar 

  • Salibury, M. H., Stephen, R., Christensen, N. I., Francheteau, J., Hammano, Y., Hobart, M., and Johnson, D., 1979, The Physical State of the Upper Levels of Cretaceous Oceanic Crust from the Results of Logging, Laboratory Studies and the Oblique Seismic Experiment at DSDP sites 417 and 418, in Deep Drill Results in the Atlantic Ocean: Ocean Crust, Maurice Ewing Ser. 2, AGU, Washington, DC, 113–134.

    Google Scholar 

  • Savage, J. C., 1966, Thermoelastic Attenuation of Seismic Waves by Cracks, J. Geophys. Res. 71, 3929–3938.

    Google Scholar 

  • Spencer, T. W., Jr., 1981, Stress Relaxations at Low Frequencies in Fluid-Saturated Rocks: Attenuation and Modulus Dispersion. J. Geophys. Res. 86, 1803–1812.

    Google Scholar 

  • Toksoz, M. N., Johnston, D. H., and Timer, A., 1979, Attenuation of Seismic Waves in Dry and Saturated Rocks, I, Laboratory Measurements, Geophysics 44, 681–690.

    Google Scholar 

  • Volarovich, M. P. and Gurvich, A. S., 1957, Investigation of Dynamic Moduli of Elasticity for Rocks in Relation to Temperature, Bull. (Izv.) Acad. Sci. USSR, Geophys. Ser. 4, 1–9.

    Google Scholar 

  • Volarovich, M. P., Levykin, A. I., and Sizov, V. P., 1960, Investigation of the Attenuation of Elastic Waves in Rock Specimens, Bull. (Izv.) Acad. Sci. USSR, Geophys. Ser. 8, 793–797.

    Google Scholar 

  • Walsh, J. B., 1966, Seismic Wave Attenuation in Rock Due to Friction, J. Geophys. Res. 71, 2591–2599.

    Google Scholar 

  • Wenner, D. B. and Taylor, Jr, .H. P., 1973, Oxygen and Hydrogen Isotope Studies of the Serpentinization of Ultramafic Rocks in Oceanic Environments and Continental Ophiolite Complexes, Am. J. Sci. 273, 207–239.

    Google Scholar 

  • Wepfer, W. W. and Christensen, N. I., 1990, Compressional Wave Attenuation in Oceanic Basalts, J. Geophys. Res. 95, 17431–17439.

    Google Scholar 

  • Winkler, K. W., 1983, Frequency Dependent Ultrasonic Properties of High-Porosity Sandstones, J. Geophys. Res. 88, 9493–9499.

    Google Scholar 

  • Winkler, K. W., 1985, Dispersion Analysis of Velocity and Attenuation in Berea Sandstone, J. Geophys. Res. 90, 6793–6800.

    Google Scholar 

  • Winkler, K. W. and Plona, T. J., 1982, Technique for Measuring Ultrasonic Velocity and Attenuation Spectra in Rocks Under Pressure, J. Geophys. Res. 87, 10776–10780.

    Google Scholar 

  • Zemanek, J. and Rudnick, I., 1961, Attenuation and Dispersion of Elastic Waves in a Cylindrical Bar, J. Acoust. Soc. Am. 33, 1283–1288.

    Google Scholar 

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  1. Department of Earth and Atmospheric Sciences, Purdue Rock Physics Laboratory, Purdue University, 47907, West Lafayette, IN, USA

    W. W. Wepfer & N. I. Christensen

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  1. W. W. Wepfer
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  2. N. I. Christensen
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Wepfer, W.W., Christensen, N.I. Q structure of the oceanic crust. Mar Geophys Res 13, 227–237 (1991). https://doi.org/10.1007/BF00369151

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