Skip to main content

Feasibility study of the geoelectric structure of the Araguainha impact, Brazil


We have re-examined the modelling of magnetotelluric and GDS soundings carried out on the Araguainha Dome, Brazil, published a few years ago, in the light of a new modelling method and with particular stress on the induction of the vertical component of the magnetic field, which had been neglected in the early publications. By careful selection of the period range of the measured data, we obtain a set of radially symmetric induction arrows. This symmetry is taken as a first order assumption of the modelling scheme. The result is an improvement of the resolution of the radial distribution of depths to the crater basement. Due to the poor MT site coverage of the crater area, this work must be considered a feasibility study rather than a final modelling contribution.


  1. Bath, M., Spectral Analysis in Geophysics, 563 pp., Elsevier, 1974.

    Google Scholar 

  2. Cordani, U. G., B. B. B. Neves, R. A. Fuck, R. Porto, A. Thomaz Filho, and F. M. B. Cunha, Estudo preliminar de integracao do Pré-Cambriano com os eventos tectonicos das bacias sedimentares brasileiras, Bol Cienc. Técn Petrol, 15, 1–70, 1984.

    Google Scholar 

  3. Crósta, A. P., J. C. Gaspar, and M. A. F. Candia, Feicoes de metamorfismo de impacto no Domo de Araguainha, Rev. Bras. Geocienc, 11, 139–146, 1981.

    Google Scholar 

  4. Dietz, R. S. and B. M. French, Two probable astroblemes in Brazil, Nature, 244, 561–562, 1973.

    Article  Google Scholar 

  5. Engelhardt, W. V., S. K. Matthai, and J. Walzebuck, Araguainha impact crater, Brazil: 1. The interior part of the uplift, Meteoritics, 27, 442–457, 1992.

    Article  Google Scholar 

  6. Fischer, G., P.-A. Schnegg, M. Peguiron, and B. V. Le Quang, An analytic one-dimensional magnetotelluric inversion scheme, Geophys. J. R. astr. Soc., 67, 257–278, 1981.

    Article  Google Scholar 

  7. Mackie, R. L., J. T. Smith, and T. R. Madden, Three-dimensional electromagnetic modeling using finite difference equations: the magnetotelluric example, Radio Sci., 923–935, 1994.

  8. Masero, W., P.-A. Schnegg, and S. L. Fontes, A magnetotelluric investigation of the Araguainha impact structure in Mato Grosso-Goias, central Brazil, Geophys. J. Int., 116, 377–392, 1994.

    Article  Google Scholar 

  9. Masero, W., G. Fischer, and P.-A. Schnegg, Crustal deformation in the region of the Araguainha impact, Brazil, Phys. Earth Planet. Inter., 101, 271–289, 1997.

    Article  Google Scholar 

  10. Pilkington, M. and R. A. F. Grieve, The geophysical signature of terrestrial impact craters, Rev. Geophys., 30, 161–181, 1992.

    Article  Google Scholar 

  11. Schnegg, P.A., A computing method for 3D magnetotelluric modelling directed by polynomials, Earth Planets Space, 51, 1005–1012, 1999.

    Article  Google Scholar 

  12. Theilen-Willige, B., The Araguainha astrobleme/Central Brazil, Geolog. Rundschau, 71, 318–327, 1982.

    Article  Google Scholar 

Download references

Author information



Corresponding author

Correspondence to Pierre-André Schnegg.

Rights and permissions

Reprints and Permissions

About this article

Verify currency and authenticity via CrossMark

Cite this article

Schnegg, P., Fontes, S.L. Feasibility study of the geoelectric structure of the Araguainha impact, Brazil. Earth Planet Sp 54, 597–606 (2002).

Download citation


  • Apparent Resistivity
  • Impact Crater
  • Radial Symmetry
  • Sediment Thickness
  • Walsh Function