1887
Volume 39, Issue 1
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

Abstract

To construct in situ velocity-porosity relationships for oceanic basalt, considering crack features, P- and S-wave velocity measurements on basaltic samples obtained from the eastern flank of the Juan de Fuca Ridge were carried out under confining pressures up to 40 MPa. Assuming that the changes in velocities with confining pressures are originated by micro-crack closure, we estimated micro-crack aspect ratio spectra using the Kuster-Toksöz theory. The result demonstrates that the normalised aspect ratio spectra of the different samples have similar characteristics. From the normalised aspect ratio spectrum, we then constructed theoretical velocity-porosity relationships by calculating an aspect ratio spectrum for each porosity. In addition, by considering micro-crack closure due to confining pressure, a velocity-porosity relationship as a function of confining pressure could be obtained. The theoretical relationships that take into account the aspect ratio spectra are consistent with the observed relationships for over 100 discrete samples measured at atmospheric pressure, and the commonly observed pressure dependent relationships for a wide porosity range. The agreement between the laboratory-derived data and theoretically estimated values demonstrates that the velocity-porosity relationships of the basaltic samples obtained from the eastern flank of the Juan de Fuca Ridge, and their pressure dependence, can be described by the crack features (i.e. normalised aspect ratio spectra) and crack closure.

© 2008 ASEG
Loading

Article metrics loading...

/content/journals/10.1071/EG08001
2008-03-01
2026-01-14

  • From This Site

    /content/journals/10.1071/EG08001
    dcterms_title,dcterms_subject,pub_keyword
    -contentType:Journal -contentType:Contributor -contentType:Concept -contentType:Institution
    10
    5
Loading full text...

Full text loading...

References

  1. Alt J. C. Honnorez J. Laverne C. Emmermann R. 1986 Hydrothermal alteration of a 1 km section through the upper oceanic crust, Deep Sea Drilling Project hole 504B: mineralogy, chemistry, and evolution of seawater-basalt interactions: Journal of Geophysical Research 91 10309 10335
    [Google Scholar]
  2. Berryman J. G. 1980 Long-wavelength propagation in composite elastic media: Journal of the Acoustical Society of America 68 1809 1831 doi:10.1121/1.385171
    [Google Scholar]
  3. Berryman J. G. Berge P. A. 1996 Critique of two explicit schemes for estimating elastic properties of multiphase composites: Mechanics of Materials 22 149 164 doi:10.1016/0167-6636(95)00035-6
    [Google Scholar]
  4. Biot M. A. 1955 Theory of elasticity and consolidation for a porous anisotropic solid: Journal of Applied Physics 26 115 135
    [Google Scholar]
  5. Birch F. 1960 The velocity of compressional waves in rocks to 10 kilobars: Journal of Geophysical Research 65 1083 1102
    [Google Scholar]
  6. Cerney B. , and Carlson R. L., 1999, The effect of cracks on the seismic velocities of basalt from site 990, southeast Greenland margin, in H.C Larsen, R A Duncan, J F Allan, and K Brooks, eds., Proceedings of the Ocean Drilling Program, Scientific Results163: College Station, TX (Ocean Drilling Program), 29–35.
  7. Cheng C. H. Toksöz M. N. 1979 Inversion of seismic velocities for the pore aspect ratio spectrum of a rock: Journal of Geophysical Research 84 7533 7543
    [Google Scholar]
  8. Davis E. E. Currie R. G. 1993 Geophysical observations of the northern Juan de Fuca Ridge system: lessons in sea-floor spreading: Canadian Journal of Earth Sciences 30 278 300
    [Google Scholar]
  9. Expedition 301 Scientists, 2005, Site U1301, in A. T. Fisher, T. Urabe, A. Klaus, and the Expedition 301 Scientists, Proceedings of the Integrated Ocean Drilling Program301 2005: College Station TX (Integrated Ocean Drilling Program Management International, Inc.),  doi:10.2204/iodp.proc.301.106
  10. Fisher A. T. Becker K. Davis E. E. 1997 The permeability of young oceanic crust east of Juan de Fuca Ridge determined using borehole thermal measurements: Geophysical Research Letters 24 1311 1314 doi:10.1029/97GL01286
    [Google Scholar]
  11. Fisher A. T. , and Davis E. E. 2000, An introduction to the scientific results of Leg 168, in A T Fisher, E E Davis, and C Escutia, eds, Proceedings of the Ocean Drilling Program, Scientific Results, 168, College Station TX (Ocean Drilling Program), 3–5.
  12. Fisher A. T. , Urabe T. , Klaus A. and the Expedition 301 Scientists 2005, Integrated Ocean Drilling Program, U.S Implementing Organization Expedition 301, Scientific Prospectus, The hydrogeologic architecture of basaltic oceanic crust: compartmentalization, anisotropy, microbiology, and crustal-scale properties on the eastern flank of Juan de Fuca Ridge.
  13. Johnston D. H. Toksöz M. N. Timur A. 1979 Attenuation of seismic waves in dry and saturated rocks. II: Mechanisms: Geophysics 44 691 711 doi:10.1190/1.1440970
    [Google Scholar]
  14. Hudson J. A. 1981 Wave speeds and attenuation of elastic waves in material containing cracks: Geophysical Journal of the Royal Astronomical Society 64 133 150
    [Google Scholar]
  15. Hyndman R. D. 1979 Poisson’s ratio in the oceanic crust: A review: Tectonophysics 59 321 333 doi:10.1016/0040-1951(79)90053-2
    [Google Scholar]
  16. Knight R. Nolen-Hoeksema R. 1990 A laboratory study of the dependence of elastic wave velocities on pore scale fluid distribution: Geophysical Research Letters 17 1529 1532
    [Google Scholar]
  17. Kuster G. T. Toksöz M. N. 1974 Velocity and attenuation of seismic waves in two-phase media, Part 1. Theoretical formulations: Geophysics 39 587 606 doi:10.1190/1.1440450
    [Google Scholar]
  18. Ludwig R. J. , Iturrino G. J. , and Rona P. A., 1998, Seismic velocity-porosity relationship of sulfide, sulfate, and basalt samples from the TAG hydrothermal mound, in P M Herzig, S.E Humphris, D J Miller, R A Zierenberg, eds., Proceedings of the Ocean Drilling Program, Scientific Results, 158: College Station, TX (Ocean Drilling Program), 313–327.
  19. Mavko G. , Mukerji T. , and Dvorkin J., 1998, The Rock Physics Handbook, Tools for Seismic Analysis of Porous Media, Cambridge University Press.
  20. Shearer P. M. 1988 Cracked media, Poisson’s ratio and the structure of the upper oceanic crust: Geophysical Journal 92 357 362 doi:10.1111/j.1365-246X.1988.tb01149.x
    [Google Scholar]
  21. Swift S. A. Lizarralde D. Stephen R. A. Hoskins H. 1998 Velocity structure in upper ocean crust at Hole 504B from vertical seismic profiles: Journal of Geophysical Research 103 15361 15376 doi:10.1029/98JB00766
    [Google Scholar]
  22. Toksöz M. N. Cheng C. H. Timur A. 1976 Velocity of seismic waves in porous rocks: Geophysics 41 621 645 doi:10.1190/1.1440639
    [Google Scholar]
  23. Toksöz M. N. Johnston D. H. Timur A. 1979 Attenuation of seismic waves in dry and saturated rocks: 1. Laboratory measurements: Geophysics 44 681 690 doi:10.1190/1.1440969
    [Google Scholar]
  24. Tompkins M. J. Christensen N. L. 1999 Effect of pore pressure on compressional wave attenuation in a young oceanic basalt: Geophysical Research Letters 26 1321 1324 doi:10.1029/1999GL900216
    [Google Scholar]
  25. Tsuji T. , and Yamaguchi H., 2007, Improvement of Mineral Mapping Method: Application of Neural Network System to Elemental Maps by Electron Microprobe Analyzer, Proceedings of the 117th SEGJ Conference, 1–4.
  26. Walsh J. B. 1966 Seismic attenuation in rock due to friction: Journal of Geophysical Research 71 2591 2599
    [Google Scholar]
  27. Wepfer W. W. Christensen N. I. 1991 Q structure of the oceanic crust: Marine Geophysical Researches 99 3043 3056
    [Google Scholar]
  28. Wilkens R. H. , Christensen N. I. , and Slater L. 1983, High-pressure seismic studies of Leg 69 and 70 basalts, in J R Cann, M G Langseth, J Honnorez, R P Von Herzen, and S M White, et al., Initial Reports of the Deep Sea Drilling Project 69, 683–686.
  29. Wilkens R. H. , Schultz D. , and Carlson R. L., 1988, Relationship of resistivity, velocity, and porosity for basalts from downhole well logging measurements in Hole 418A:, in M. H. Salisbury and J.H. Scott, et al., Proceedings of the Ocean Drilling Program, Scientific Results102, 69–78.
     [Google Scholar]
  30. Wilkens R. H. Fryer G. J. Karsten J. 1991 Evolution of porosity and seismic structure of upper oceanic crust: importance of aspect ratios: Journal of Geophysical Research 96 17891 17995
    [Google Scholar]
  31. Wilkens R. H. , and Salisbury M. H., 1996, Microstructure and physical properties of samples from Hole 896A, in J C Alt, H Kinoshita, L B Stokking, and P J Michael, et al., Proceedings of the Ocean Drilling Program, Scientific Results148B, 365–374.
/content/journals/10.1071/EG08001
Loading
Velocity-porosity relationships in oceanic basalt from eastern flank of the Juan de Fuca Ridge: The effect of crack closure on seismic velocity
Exploration Geophysics 39, 41 (2008); https://doi.org/10.1071/EG08001
/content/journals/10.1071/EG08001
/content/journals/10.1071/EG08001
Loading

Data & Media loading...

  • Article Type: Research Article
Keyword(s): crack aspect ratio; Integrated Ocean Drilling Program; Kuster-Toksöz theory; oceanic basalt; velocity-porosity relationship

Most Cited This Month Most Cited RSS feed

This is a required field
Please enter a valid email address
Approval was a Success
Invalid data
An Error Occurred
Approval was partially successful, following selected items could not be processed due to error