E. Sokolova

Electromagnetic images of the deep structure of the Trans-European Suture Zone beneath Polish Pomerania

A large-scale international electromagnetic experiment has been carried out in northwest Poland and northeast Germany. The main goal was to study the deep conductivity structure across the Trans-European Suture Zone, which is the most prominent tectonic structure of Phanerozoic age in Europe. Electromagnetic measurements were carried out mainly along seismic profiles P2, LT-7, and LT-2 crossing the suture zone and running in the northeastern direction. Strike and dimensionality analyses indicate that a geoelectrical strike of N60 degrees W common to both profiles LT-7 and P2 can be estimated. This strike direction was used to project and rotate all transfer functions and both profiles were subjected to 2D inversion using three different approaches. The results show the presence of highly conductive Cenozoic-Mesozoic sedimentary cover reaching depths up to 3 km. A significant conductivity anomaly beneath the central part of the TESZ, called the Central Polish Anticlinorium, has been well resolved at midcrustal depths. The upper mantle of the Precambrian East European Craton is more resistive than, adjacent to the West, the younger Paleozoic Platform.

Probing electrical conductivity of the Trans-European Suture Zone

The Trans-European Suture Zone (TESZ) is the largest tectonic boundary in Europe, crossing northwest-southeast through central Europe from the North Sea to the Black Sea. More than 2000 kilometers long, it constitutes a complex transition between the thick and cold East European Craton (EEQ/Baltic Shield, created more than 650 million years ago (Ma) during the Precambrian, and the warmer, younger Paleozoic (650 to 250 Ma) central European mobile belts.