1887
Volume 51, Issue 1
  • ISSN: 0812-3985
  • E-ISSN: 1834-7533

Abstract

ABSTRACT

This paper presents the results of airborne electromagnetic induced polarisation inversions using the Maximum Phase Angle (MPA) model for a helicopter time domain survey in the Quadrilátero Ferrífero area, Minas Gerais State (MG), Brazil. The inversions were conducted using a laterally constrained robust scheme, in order to decrease the difficulties to recover the multi-parametric model in a very ill-posed inverse problem, often found in induced polarisation studies. A set of six flight lines over the Lamego gold mine mineralised structure were inverted using the MPA re-parameterisation of the Cole–Cole model and also the classical resistivity-only parameterisation, in order to understand the implications of the induced polarisation effect in the data and, consequently, in the resistivity model. A synthetic study was also conducted, seeking to understand what to expect from the resistivity-only inversions in the real data. According to borehole lithological data and previous structural knowledge from the literature, the results from the Maximum Phase Angle approach indicate an important chargeable body that seems to be in good agreement with a sulfide enriched carbonaceous/graphite and altered mafic unities, which are important markers for the gold mineralisation.

© 2019 Australian Society of Exploration Geophysicists
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2020-01-02
2026-01-21

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References

  1. Auken, E., A.V. Christiansen, G. Fiandaca, C. Schamper, A.A. Behroozmand, A. Binley, E. Nielsen, et al. 2015 An overview of a highly versatile forward and stable inverse algorithm for airborne, ground-based and borehole electromagnetic and electric data. Exploration Geophysics46: 223–35. doi: 10.1071/EG13097
     https://doi.org/10.1071/EG13097 [Google Scholar]
  2. Auken, E., A.V. Christiansen, J.A. Westergaard, C. Kirkegaard, N. Foged, and A. Viezzoli 2009 An integrated processing scheme for high-resolution airborne electromagnetic surveys, the skytem system. Exploration Geophysics40: 184–92. doi: 10.1071/EG08128
     https://doi.org/10.1071/EG08128 [Google Scholar]
  3. Fiandaca, G., A. Christiansen, and E. Auken 2015 Depth of investigation for multi-parameters inversions. Near Surface Geoscience 2015-21st European Meeting of Environmental and Engineering Geophysics.
  4. Fiandaca, G., C. Lin, E. Auken, and A. Christiansen 2018a Robust inversion of induced polarization effects in airborne transient electromagnetic. AEM2018 – 7th International Workshop on airborne electromagnetics – Extended Abstracts.
     [Google Scholar]
  5. Fiandaca, G., L.M. Madsen, and P.K. Maurya 2018b Re-parameterizations of the Cole-Cole model for improved spectral inversion of induced polarization data. Near Surface Geophysics16: 385–99.
     [Google Scholar]
  6. Gisselø, P.G., and N.S. Nyboe 2018 Optimized for depth of investigation. Aem2018 – 7th International Workshop on airborne electromagnetics. AEM2018 – 7th International Workshop on airborne electromagnetics – Extended Abstracts.
     [Google Scholar]
  7. Kaminski, V., and A. Viezzoli 2017 Modeling induced polarization effects in helicopter time-domain electromagnetic data: Field case studies. Geophysics82: B49–61. doi: 10.1190/geo2016‑0103.1
     https://doi.org/10.1190/geo2016-0103.1 [Google Scholar]
  8. Kang, S., D. Fournier, and D.W. Oldenburg 2017 Inversion of airborne geophysics over the Do-27/Do-18 Kimberlites – Part 3: Induced polarization. Interpretation5: T327–40. doi: 10.1190/INT‑2016‑0141.1
     https://doi.org/10.1190/INT-2016-0141.1 [Google Scholar]
  9. Kang, S., and D.W. Oldenburg 2016 On recovering distributed Ip information from inductive source time domain electromagnetic data. Geophysical Journal International207: 174–96. doi: 10.1093/gji/ggw256
     https://doi.org/10.1093/gji/ggw256 [Google Scholar]
  10. Kratzer, T., and J. Macnae 2012 Induced polarization in airborne Em. Geophysics77: E317–27. doi: 10.1190/geo2011‑0492.1
     https://doi.org/10.1190/geo2011-0492.1 [Google Scholar]
  11. Lin, C., G. Fiandaca, E. Auken, M.A. Couto, and A. Christiansen 2019 A discussion of 2d induced polarization effects in airborne electromagnetic and inversion with a robust 1d laterally constrained inversion scheme. Submitted to Geophysics.
  12. Macnae, J. 2016 Quantifying airborne induced polarization effects in helicopter time domain electromagnetics. Journal of Applied Geophysics135: 495–502. doi: 10.1016/j.jappgeo.2015.10.016
     https://doi.org/10.1016/j.jappgeo.2015.10.016 [Google Scholar]
  13. Marchant, D., E. Haber, and D. Oldenburg 2014 Three-dimensional modeling of Ip effects in time-domain electromagnetic data. Geophysics79: E303–14. doi: 10.1190/geo2014‑0060.1
     https://doi.org/10.1190/geo2014-0060.1 [Google Scholar]
  14. Martins, B.d.S., L.M. Lobato, C.A. Rosière, S.G. Hagemann, J.O.S. Santos, F.L.d.S.P. Villanova, R.C. Figueiredo e Silva, and L.H. de Ávila Lemos 2016 The Archean Bif-Hosted Lamego gold deposit, Rio Das Velhas greenstone belt, Quadrilátero Ferrífero: Evidence for Cambrian structural Modification of an Archean orogenic gold deposit. Ore Geology Reviews72: 963–88. doi: 10.1016/j.oregeorev.2015.08.025
     https://doi.org/10.1016/j.oregeorev.2015.08.025 [Google Scholar]
  15. Pelton, W.H., S.H. Ward, P.G. Hallof, W.R. Sill, and P.H. Nelson 1978 Mineral discrimination and removal of Inductive coupling with Multifrequency Ip. Geophysics43: 588–609. doi: 10.1190/1.1440839
     https://doi.org/10.1190/1.1440839 [Google Scholar]
  16. Seigel, H.O. 1959 Mathematical Formulation and type curves for induced polarization. Geophysics24: 547–65. doi: 10.1190/1.1438625
     https://doi.org/10.1190/1.1438625 [Google Scholar]
  17. Smith, B.D., C. Tippens, V. Flanigan, and H. Sadek 1983 Preliminary results of spectral induced polarization measurements, Wadi Bidah District, Kingdom of Saudi Arabia. US Geological Survey, Open-File Report, 83–612.
  18. Viezzoli, A., G. Fiandaca, and S. Sergio 2013 Study on the potential of recovering Ip parameters from airborne tem data in layered geology. 6th International AEM Conference & Exhibition.
     [Google Scholar]
  19. Viezzoli, A., V. Kaminski, and G. Fiandaca 2017 Modeling induced polarization effects in helicopter time domain electromagnetic data: Synthetic case studies. Geophysics82: E31–50. doi: 10.1190/geo2016‑0096.1
     https://doi.org/10.1190/geo2016-0096.1 [Google Scholar]
  20. Viezzoli, A., V. Kaminskiy, N. Ebner, and A. Menghini 2016 Extracting Ip information from aem data to improve the hydrogeological interpretation. ASEG-PESA-AIG 2016.
     [Google Scholar]
/content/journals/10.1080/08123985.2019.1682458
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AEMIP robust inversion using maximum phase angle Cole–Cole model re-parameterisation applied for HTEM survey over Lamego gold mine, Quadrilátero Ferrífero, MG, Brazil
Exploration Geophysics 51, 170 (2020); https://doi.org/10.1080/08123985.2019.1682458
/content/journals/10.1080/08123985.2019.1682458
/content/journals/10.1080/08123985.2019.1682458
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  • Article Type: Research Article
Keyword(s): Airborne electromagnetics; induced polarization; maximum phase angle

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