Volume 9 Number 1
  • E-ISSN: 1365-2478



Abnormal phenomenons such as refractions and diffractions are more readily seen on cross‐sections produced in magnetic processing offices than on single records. The result is that the understanding of these phenomenons intervenes more and more in the interpretation of the data.

Our purpose is to proceed here to a restatement of the geometric properties related to these phenomenons and to make an attempt to distinguish between what is useful for the interpretation and what is not.

To begin with we shall call our attention on diffractions and refractions over faults permitting to recognize the faults or to precise them, then on diffractions caused by irregularities of the surface forming the common boundary of heterogeneous media (more or less deep erosion surface, basement rock, …). The following phenomenons are classified as parasites:

  • 1)   refractions following very shallow horizons, mostly related to topographic accidents,
  • 2)   diffractions on the upward path caused by shallow faults,
  • 3)   diffractions in the horizontal plane, found either in marine seismic or in case of heterogeneities “wrapt up” inside of an homogeneous overthrust.


Article metrics loading...

Loading full text...

Full text loading...


  1. Deacon, L. E., 1943, An Analysis of Abnormal Reflections, Geophysics, VIII, p. 3–13.
    [Google Scholar]
  2. Ellis, L. G. and Winterhalter, A. C., 1956, Unusual Events in Offshore Seismics, Geophysics, XXI, p. 755–764.
    [Google Scholar]
  3. Hagedoorn, J. G., 1954, A Process of Seismic Reflection Interpretation, Geoph. Prosp., II, p. 85–127.
    [Google Scholar]
  4. Krey, T., 1952, The Significance of Diffraction in the Investigation of Faults, Geophysics, XVII, p. 843–858.
    [Google Scholar]
  5. Ledoux, Y., 1957, Quelques exemples de diffractions en sismique‐réfraction et leur application à la détermination des vitesses verticales, Geoph. Prosp., V, p. 392–406.
    [Google Scholar]
  6. Richard, H., 1953, Réflexions multiples obliques, Geoph. Prosp., I, p. 49–63.
    [Google Scholar]
  7. Robinson, W. B., 1945, Refraction Waves Reflected from a Fault Zone, Geophysics, X, P. 535–545.
    [Google Scholar]
  • Article Type: Research Article
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