1887

Abstract

Summary

SPM effects, which are mainly caused by fine-grained iron particles such as maghemite and magnetite constitute a geological noise in modern airborne transient Time Domain EM (TDEM) systems. Therefore, their identification and discrimination is important when exploring for bedrock conductors associated with metallic mineralisation such as nickel and sulphides. In the transient TDEM data, they are manifested by a power law decay fit at mid-late time close to -1.

In this paper, we describe other approaches for identifying and discriminating SPM anomalies observed in the transient TDEM data from Greenland, including a) innovative dual-EM receiver configuration (vertical EM gradiometer), and b) a multiple criteria pattern recognition approach, based on maximum likelihood algorithm. As a result, many SPM-related detected by airborne TDEM surveys were identified and were hence discriminated from further follow-up. Diamond drill testing in 2016 performed on selected targets that were categorized as non-SPM related, has confirmed their link to bedrock conductors and sulphide mineralization.

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/content/papers/10.3997/2214-4609.201602099
2016-09-04
2020-04-07
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References

  1. Buselli, G.
    [1982] The effect of near-surface superparamagnetic material on electromagnetic measurements. Geophysics, 4(9), 1315–1324.
    [Google Scholar]
  2. Baruskov, P.O. and Fainberg, E.B.
    [2001] Superparamagnetic effect over gold and nickel deposits, European Journal of Environmental and Engineering Geophysics, 6, 61–72.
    [Google Scholar]
  3. Campbell, J.B and Wynne, R.H.
    [2011] Introduction to remote sensing, Fifth edition. The Guilford Press, New York, USA.
    [Google Scholar]
  4. Henriksen, N., Higgins, A.K., Kalsbeek, F. and Pulvertaft, T.C.R.
    [2009] Greenland from Archaean to Quaternary. Descriptive text to the 1995 Geological map of Greenland, 1: 2 500 000, Second edition. Geological Survey of Denmark and Greenland (Bulletin 18).
    [Google Scholar]
  5. Lee, T.
    [1984] The transient electromagnetic response of a magnetic or superparamgnetic ground. Geophysics, 49(7), 854–860.
    [Google Scholar]
  6. Mutton, P.
    [2012] Superparamagnetic effects in EM surveys for Mineral Exploration. 22nd ASEG conference and Exhibition, Expanded Abstracts, 1–6.
    [Google Scholar]
  7. Mutton, P. and Mortimer, R.
    [2009] Superparamagnetic effects in airborne EM survey data. 20th ASEG conference and Exhibition, Expanded Abstracts, 1–15.
    [Google Scholar]
  8. Kratzer, T. Macnae, J. and Mutton, P.
    [2013] Correcting for SPM effects in airborne EM. 23rd ASEG conference and Exhibition, Expanded Abstracts, 1–4.
    [Google Scholar]
  9. Kwan, K., Plastow, G., Legault, J.M., Prikhodko, A., Bournas, N., Orta, M. and Taylor, S.
    [2016] Evidence and identification of SPM of airborne TDEM data from Greenland. SEG Expanded Abstracts, 1–4.
    [Google Scholar]
  10. Prikhodko, A. Morrison, E. Bagrianski, A. Kuzmin, P. Tishin, P. and Legault, J.
    [2010] Evolution of VTEM-Technical solutions for effective exploration. 21st ASEG conference and Exhibition, Expanded Abstracts, 1–4.
    [Google Scholar]
  11. Sattel, D. and Mutton, P.
    [2014] Gradiometer measurements for resolving SPM responses in airborne EM data. SEG Expanded Abstracts, 1759–1762.
    [Google Scholar]
  12. Witherly, K., Irvine, R. and Morrison, E.B.
    [2004] The Geotech VTEM time domain electromagnetic system: SEG, Expanded Abstracts, 1217–1221.
    [Google Scholar]
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