Earth Planets Space, Vol. 54 (No. 5), pp. 597-606, 2002
Pierre-André Schnegg1 and S. L. Fontes2
1Institut de Géologie, CH-2007 Neuchâtel, Switzerland
2CNPq-Observatorio Nacional, 20921-400 Rio de Janeiro, Brazil
(Received December 7, 2000; Revised October 4, 2001; Accepted October 4, 2001)
Abstract: 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.