1887
Volume 58 Number 6
  • E-ISSN: 1365-2478

Abstract

ABSTRACT

The WSINV3DMT code makes the implementation of 3D inversion of magnetotelluric data feasible using a single PC. Audio‐magnetotelluric data were collected along two profiles in a Cu‐Ni mining area in Xinjiang, China, where the apparent resistivity and phase curves, the phase tensors and the magnetic induction vectors indicate a complex 3D conductivity structure. 3D inversions were carried out to reveal the electrical structure of the area. The final 3D model is selected from the inversion results using different initial Lagrange values and steps. The relatively low root‐mean‐square (rms) misfit and model norm indicate a reliable electrical model. The final model includes four types of low resistivity areas, the first ones coincide with the known location of an orebody and further forward modelling indicates that they are not in full connectivity to form a low resistivity zone. The second ones are not controlled by magnetotelluric sites and embody little information of the observed data, they are considered as tedious structures. The third one is near to the regional Kangguer fault and should be treated carefully considering the effect of the fault. The last ones are isolated and existing at a limited level as the first ones, they should be paid more attention to.

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2010-06-09
2024-03-29
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References

  1. AlumbaughD.L., NewmanG.A., PrevostL. and ShadidJ.N.1996. Three‐dimensional wideband electromagnetic modeling on massively parallel computers. Radio Science31, 1–23.
    [Google Scholar]
  2. AvdeevD.B.2005. Three‐dimensional electromagnetic modeling and inversion from theory to application. Surveys in Geophysics26, 767–799.
    [Google Scholar]
  3. AvdeevD.B. and AvdeevaA.D.2006. A rigorous three‐dimensional magnetotelluric inversion. Progress in Electromagnetics Research62, 41–48.
    [Google Scholar]
  4. BahrK.1988. Interpretation of the magnetotelluric impedance tensor, regional induction and local distortion. Journal of Geophysics62, 119–127.
    [Google Scholar]
  5. BahrK.1991. Geological noise in magnetotelluric data: a classification of distortion types. Physics of the Earth and Planetary Interiors66, 24–38.
    [Google Scholar]
  6. BerdichevskyM.N., DmitrievV.I. and PozdnjakovaE.E.1998. On two‐dimensional interpretation of magnetotelluric soundings. Geophysical Journal International133, 585–606.
    [Google Scholar]
  7. CaldwellT.G., BibbyH.M. and BrownC.2004. The magnetotelluric phase tensor. Geophysical Journal International158, 457–469.
    [Google Scholar]
  8. ConstableS.C., ParkerR.L. and ConstableC.G.1987. Occam's inversion – A practical algorithm for generating smooth models from electromagnetic sounding data. Geophysics52, 289–300.
    [Google Scholar]
  9. FarquharsonC.G. and CravenJ.A.2009. Three‐dimensional inversion of magnetotelluric data for mineral exploration: An example from the McArthur River uranium deposit, Saskatchewan, Canada. Journal of Applied Geophysics68, 450–458.
    [Google Scholar]
  10. FarquharsonC.G., OldenburgD.W., HaberE. and ShekhtmanR.2002. An algorithm for the three‐dimensional inversion of magnetotelluric data. 72nd SEG meeting, Salt Lake City, Utah, USA, Expanded Abstracts, 649–652.
  11. GroomR.W. and BaileyR.C.1989. Decomposition of magnetotelluric impedance tensors in the presence of local three‐dimensional galvanic distortion. Journal of Geophysical Research94, 1913–1925.
    [Google Scholar]
  12. DeGroot‐HedlinC.1991. Removal of static shift in two dimensions by regularized inversion. Geophysics56, 2102–2106.
    [Google Scholar]
  13. DeGroot‐HedlinC. and ConstableS.C.1990. Occams's inversion to generate smooth, two‐dimensional models from magnetotelluric data. Geophysics55, 1613–1624.
    [Google Scholar]
  14. DeGroot‐HedlinC. and ConstableS.C.2004. Inversion of magnetotelluric data for 2D structure with sharp resistivity contrasts. Geophysics69, 78–86.
    [Google Scholar]
  15. HanN., NamM.J., KimH.J., LeeT.J., SongY. and SuhJ.H.2008. Efficient three‐dimensional inversion of magnetotelluric data using approximate sensitivities. Geophysical Journal International175, 477–485.
    [Google Scholar]
  16. HeiseW., CaldwellT.G., BibbyH.M. and BannisterS.C.2008. Three‐dimensional modelling of magnetotelluric data from the Rotokawa geothermal field, Taupo Volcanic Zone, New Zealand. Geophysical Journal International173, 740–750.
    [Google Scholar]
  17. InghamM.R., BibbyH.M., HeiseW., JonesK.A., CairnsP., DravitzkiS. et al . 2009. A magnetotelluric study of Mount Ruapehu volcano, New Zealand. Geophysical Journal International179, 887–904.
    [Google Scholar]
  18. JonesA.G.1988. Static shift of magnetotelluric data and its removal in a sedimentary basin environment. Geophysics53, 967–978.
    [Google Scholar]
  19. LedoJ.2005. 2‐D versus 3‐D magnetotelluric data interpretation. Surveys in Geophysics26, 511–543.
    [Google Scholar]
  20. LedoJ., QueraltP., MartiA. and JonesA.G.2002. Two‐dimensional interpretation of three‐dimensional magnetotelluric data: An example of limitations and resolution. Geophysical Journal International150, 127–139.
    [Google Scholar]
  21. MackieR.L. and MaddenT.R.1993. Three‐dimensional magnetotelluric inversion using conjugate gradients. Geophysical Journal International115, 215–229.
    [Google Scholar]
  22. MackieR.L., RodiW. and WattsM.D.2001. 3‐D magnetotelluric inversion for resource exploration. 71st SEG meeting, San Antonio, Texas, USA, Expanded Abstracts, 1501–1504.
  23. MackieR.L., SmithJ.T. and MaddenT.R.1994. Three‐dimensional electromagnetic modeling using finite difference equations: The magnetotelluric example. Radio Science29, 923–935.
    [Google Scholar]
  24. McNeiceG.W. and JonesA.G.2001. Multisite, Multifrequency tensor decomposition of magnetotelluric data. Geophysics66, 158–173.
    [Google Scholar]
  25. MiensopustM., MartíA. and JonesA.G.2007. Inversion of synthetic data using WSINV3DMT code. 4th International Symposium on Three‐Dimensional Electromagnetics, 27–30 September, Freiberg , Germany , 27–30.
  26. NewmanG.A. and AlumbaughD.L.2000. Three dimensional magnetotelluric inversion using non‐linear conjugate gradients. Geophysical Journal International140, 410–424.
    [Google Scholar]
  27. OgawaY.1999. Constrained inversion of COPROD‐2S2 dataset using model roughness and static shift. Earth Planets Space51, 1145–1151.
    [Google Scholar]
  28. OgawaY.2002. On two‐dimensional modeling of magnetotelluric field data. Surveys in Geophysics23, 251–272.
    [Google Scholar]
  29. OgawaY. and UchidaT.1996. A two‐dimensional magnetotelluric inversion assuming Gaussian static shift. Geophysical Journal International126, 69–76.
    [Google Scholar]
  30. PadilhaA.L., VitorelloÍ., PáduaM.B. and BolognaM.S.2006. Lithospheric and sublithospheric anisotropy beneath central‐southeastern Brazil constrained by long period magnetotelluric data. Physics of the Earth and Planetary Interiors158, 190–209.
    [Google Scholar]
  31. ParkinsonW.1959. Directions of rapid geomagnetic variations. Geophysical Journal Of the Royal Astronomical Society2, 1–14.
    [Google Scholar]
  32. RodiW. and MackieR.L.2001. Nonlinear conjugate gradients algorithm for 2‐D magnetotelluric inversion. Geophysics66, 174–187.
    [Google Scholar]
  33. SanJ.Z., HuiW.D., QinK.Z., SunH., XuX.W., LiangG.H. et al . 2007. Geological characteristics of Tulargen magmatic Cu‐Ni‐Co deposit in eastern Xinjiang and its exploration direction. Mineral Deposits26, 307–316.
    [Google Scholar]
  34. SasakiY.2001. Full 3‐D inversion of electromagnetic data on PC. Journal of Applied Geophysics46, 45–54.
    [Google Scholar]
  35. SasakiY.2004. Three‐dimensional inversion of static‐shifted magnetotelluric data. Earth, Planets and Space56, 239–248.
    [Google Scholar]
  36. SchmuckerU.1970. Anomalies of geomagnetic variations in the southwestern United States. Bulletin of the Scripps Institution of Oceanography13, 1–165.
    [Google Scholar]
  37. SiemonB.1997. An interpretation technique for superimposed induction anomalies. Geophysical Journal International130, 73–88.
    [Google Scholar]
  38. SiripunvarapornW. and EgbertG.2000. An efficient data‐subspace inversion method for 2‐D magnetotelluric data. Geophysics65, 791–803.
    [Google Scholar]
  39. SiripunvarapornW. and EgbertG.2007. Data space conjugate gradient inversion for 2‐D magnetotelluric data. Geophysical Journal International170, 986–994.
    [Google Scholar]
  40. SiripunvarapornW., EgbertG. and LenburyY.2002. Numerical accuracy of magnetotelluric modeling: A comparison of finite difference approximation. Earth, Planets and Space54, 721–725.
    [Google Scholar]
  41. SiripunvarapornW., EgbertG., LenburyY. and UyeshimaM.2005a. Three‐dimensional magnetotelluric inversion, data space method. Physics of the Earth and Planetary Interiors150, 3–14.
    [Google Scholar]
  42. SiripunvarapornW., EgbertG. and UyeshimaM.2005b. Interpretation of 2‐D Magnetotelluric Profile Data with 3‐D Inversion, Synthetic Examples. Geophysical Journal International160, 804–814.
    [Google Scholar]
  43. SmithJ.T.1996. Conservative modeling of 3‐D electromagnetic fields. Part II: Biconjugate gradient solution and an accelerator. Geophysics61, 1319–1324.
    [Google Scholar]
  44. SmithJ.T. and BookerJ.R.1991. Rapid inversion of two‐ and three‐dimensional magnetotelluric data. Journal of Geophysical Research96, 3905–3922.
    [Google Scholar]
  45. UchidaT.1993. Smooth 2‐D inversion for magnetotelluric data based on statistical criterion ABIC. Journal of Geomagnetics and Geoelectrics45, 841–858.
    [Google Scholar]
  46. WannamakerP.E., StodtJ.A. and RijoL.1986. Two‐dimensional topographic responses in magnetotellurics modeled using finite elements. Geophysics51, 2131–2144.
    [Google Scholar]
  47. WannamakerP.E., StodtJ.A. and RijoL.1987. A stable finite‐element solution for two‐dimensional magnetotelluric modeling. Geophysical Journal of the Royal Astronomical Society88, 277–296.
    [Google Scholar]
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  • Article Type: Research Article
Keyword(s): 3D inversion; Forward modelling; Geologically complex area; Magnetotellurics

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