New results from amplitude preserving prestack depth migration of the Münchberg/Vogtland segment of the MVE deep seismic survey

A part of the deep seismic near normal-incidence Münchberg–Vogtland–Erzgebirge (MVE) observations located in the Saxo-Thuringian Belt at the northern rim of the Bohemian Massif has been reprocessed using the method of amplitude preserving 3D prestack depth migration. The advantage of this method is its ability to deliver a quantitative and geometrically correct image of the crustal reflectivity without preference of certain dips. The application of a prestack migration method is preferable in complex areas where diffractions and reflections with alternating dips are expected. Along the reprocessed part of the profile, location and dip of many reflective elements have considerably changed compared to the poststack migration [Z. Geol. Wiss. 22 (1994) Appendix 3.4]. The Franconian Line (FL), a major post-Variscan fault, is imaged down to 11 km depth and its fault throw can be assessed at 6 km. Observations of reflecting elements in the prolongation of the FL and a significant change of reflectivity give rise to the idea of an extent of the FL into the lower crust. High reflection amplitudes in the Vogtland area are interpreted within the scope of fluids ascending from a magmatic body at the crust-mantle boundary.