A Study of MT Distortion in Paraná Basin

This study analyses MT data from 84 sites in Paraná Basin which are contamined by noise. The data set displays 2D and 3D contributions on a 1D general background. The D+ solution was used to process the raw data and thus to deal with the observed noise. A group of aligned 2D dyke-like structures can be probably the main cause for the distortion of the 1D background. It is also shown that near-surface Iaterally smaIl bodies may also explain some of the distortions found.