1887
Volume 36 Number 2
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

A novel fixed‐source electromagnetic system has been developed. The transmitter is a large rectangular loop or grounded dipole. The transmitted waveform consists of up to five superimposed pure sinusoids at well‐separated frequencies. The receiver measures the amplitude and phase at two frequencies from a single receiver coil. The amplitude ratio is routinely calculated. Field trials with both surface and downhole configurations show that the method has advantages over the more traditional frequency‐domain Turam type and downhole electromagnetic (DHEM) systems. Among such advantages are the use of a single receiver coil and the removal of noise due to free‐space variations in transmitter‐receiver geometry. The latter is important for DHEM surveys. In terms of field procedures and quantities measured, the system is similar to time‐domain methods.

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2006-04-27
2020-04-01
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References

  1. Barlow, R.B.1981. Night Hawk Lake Geophysical Test Range results using two electromagnetic system. In Summary of Field Work, Ontario Geological Survey, miscellaneous paper 100, 152–159.
    [Google Scholar]
  2. Bosschart, R.A.1964. Analytical interpretation of fixed source electromagnetic prospecting data. Ph.D. thesis, University of Delft, The Netherlands .
  3. Crone, D.1985. Case histories in the use of Pulse EM from surface and borehole as an aid in the detection and definition of deep ore deposits. Canadian Institute of Mining Bulletin78,776, 47–51.
    [Google Scholar]
  4. Dyck, A.V.1981. A method for quantitative interpretation of wideband drillhole EM surveys in mineral exploration. Research in Applied Geophysics23, University of Toronto.
    [Google Scholar]
  5. Dyck, A.V., Bloore, M. and Valee, M.A.1981. User manual for programs PLATE and SPHERE. Research in Applied Geophysics14, University of Toronto.
    [Google Scholar]
  6. Fraser, D.C.1969, Contouring of VLF‐EM data. Geophysics34, 958–967.
    [Google Scholar]
  7. Gallagher, P.R., Ward, S.H. and Hohmann, G.W.1985. A model study of a thin plate in free space for the EM37 transient electromagnetic system. Geophysics50, 1002–1019.
    [Google Scholar]
  8. Hohmann, G.W., Van Voorhis, G.D. and Nelson, P.H.1978. A vector EM system and its field applications. Geophysics43, 1418–1440.
    [Google Scholar]
  9. Johnson, I.M. and Doborzynski, Z.1986. A novel ground EM system. Geophysics51, 396–409.
    [Google Scholar]
  10. Karous, M. and Hjelt, S.E.1983. Linear filtering of VLF dip‐angle measurements. Geophysical Prospecting31, 782–794.
    [Google Scholar]
  11. Lile, O.B.1982. On the use of multifrequency Turam in reconnaissance measurements. Norwegian Institute of Technology Trondheim, Norway .
    [Google Scholar]
  12. Lile, O.B., Pelkonen, R., Andersen, O.W. and Singsaas, P.1982. On the importance of gathered current in Turam measurements. Geoexploration19, 277–295.
    [Google Scholar]
  13. Lile, O.B., Elvebakk, H. and Berger, B.1984. Electromagnetic measurements with variable energizing cable grounding points. Geophysical Transactions30, 279–288.
    [Google Scholar]
  14. Lodha, G.S.1977. Time domain and multifrequency electromagnetic response in mineral prospecting. Research in Applied Geophysics8, University of Toronto.
    [Google Scholar]
  15. Macnae, J.C. and Walker, P.1981. The Thomas Township test target: an example of EM interpretation using simple models. Research in Applied Geophysics22, University of Toronto.
    [Google Scholar]
  16. Nabighian, M.N.1984. Foreword and introduction. Geophysics49, 849–853.
    [Google Scholar]
  17. Poddar, M.1981. Multifrequency Turam measurements over a sulphide deposit. Geophysics46, 1269–1277.
    [Google Scholar]
  18. Poddar, M.1983. A rectangular loop source of current on multilayer earth. Geophysics48, 107–109.
    [Google Scholar]
  19. Rogozinski, A.1984. Field examples of Elfast wide band detail surveys. Androtex Ltd, Toronto , Ontario .
    [Google Scholar]
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