Magnetotellurics along the Fennoscandian Long Range profile

Estimates of magnetotelluric transfer functions along the Fennoscandian Long Range (FENNOLORA) profile are presented and discussed in relation to the major lithotectonic subdivisions of the Swedish part of the Baltic shield. None of the transfer functions are found to be consistent with a one-dimensional earth structure, thereby making a quantitative interpretation difficult. However, the geological units are found to display characteristic differences in the obtained transfer functions, and in some areas a quantitative interpretation can be justified. The most interesting structure indicated is a low resistive (4 Ωm) crustal structure of lateral extension more than 150 km centred around the Skellefte ore district. A minimum thickness for this structure of 15 km is inferred.