Depth of crustal conducting layer and asthenosphere in the Pannonian basin determined by magnetotellurics

Abstract

On the basis of numerical modelling and statistical investigations of the horizontal electrical inhomogeneities (narrow fractures, change of conductance of the surface sediments) ρ min magnetotelluric (MT)-sounding curves were found to be less distorted and, therefore, they can be used for the determination of deep conducting formations in the crust and upper mantle. Carefully selected MT curves indicate the crustal conductive layer at depths of 7–13 km and the conductive asthenosphere between 50 and 80 km. The relatively shallow position of the asthenosphere corresponds to the high heat flow ( q > 80 mW m −1) in the Pannonian basin according to the empirical relation derived by Ádám (1978).