P. Schmoldt, PhD - MTNet - DIAS

11
Summary and conclusions
The key results of this thesis are (i) the development of a novel inversion approach for
cases of oblique geoelectric strike directions at crustal and mantle depths and (ii) the processing,
modelling, and interpretation of a magnetotelluric (MT) dataset acquired during
the PICASSO Phase I fieldwork campaign in central and southern Spain. Principles and
application of the novel anisotropic inversion approach in a synthetic 3D model study
were illustrated in Part III; application of this approach to a real dataset, together with
other methods used for the investigation of the Tajo Basin subsurface, were described in
Part IV. In this Chapter, results of the novel inversion approach study and the PICASSO
Phase I investigation are summarised and suggestions for future work are given. More
detailed summaries of results from the inversion approach and the PICASSO Phase I investigation
are given at the end of the respective Parts, i.e. in Sections 8.4 and 10.3.
11.1. Novel anisotropic inversion approaches for the
case of oblique geoelectric strike directions
11.1.1. Summary and conclusions
The development of the novel inversion approach was motivated by the oblique geoelectric
strike directions observed at crustal and lithospheric-mantle depths in the PICASSO
Phase I study area and the problems of commonly employed isotropic 2D inversion of
MT data in cases of oblique geoelectric strike directions. Whereas recovery of crustal
structures can, in most cases, be achieved in a straightforward manner by limiting the
modelled period range to crustal penetration depths, deriving mantle structures is more
challenging with isotropic 2D inversion in the case of an overlying crust with different
geoelectric strike direction. Thus, investigators may resort to computationally expensive
3D inversion in order to derive the electric resistivity distribution at mantle depths.
In the novel approaches presented in this thesis, electric anisotropy is used to image 2D
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