POLONAISE '97 - an international seismic experiment between Precambrian and Variscan Europe in Poland

The Trans-European Suture Zone (TESZ) comprises a series of sutures that de veloped by Palaeozoic amalgamation of the Phanerozoic Central Europe onto t he Proterozoic Baltica and East European Plate during the formation of Pang ea. Within TESZ, the Permian Basin in Poland forms the easternmost part of the Permian Central European Basin, which is bordered on the east by the Ea st European Craton (EEC) and on the southwest by the Bohemian Massif. The a xis of the basin, the Mid-Polish Trough, parallels the edge of the EEC. The Teisseyre-Tornquist Zone (TTZ) is a geological inversion zone in the Polis h Trough. A large seismic experiment, the POLONAISE'97 project, was conduct ed in Poland during May of 1997 and targeted the deep structure of the TESZ and the complex series of upper crustal features associated with it. It in cluded contributions from the geophysical communities in Poland, Denmark, t he USA, Lithuania, Germany, Finland, Sweden and Canada. This large lithosph eric seismic experiment deployed 613 instruments to record 64 shots along f ive profiles with a total length of about 2000 km. Moreover, five multichan nel seismic reflection stations (90 and 120 channels) recorded all signals from shots. Two dimensional velocity models were derived by P-wave tomograp hic inversion. These models provide an initial interpretation of this massi ve data set and allow us to present a few significant seismic and tectonic observations. One of the most important is a very distinct asymmetry betwee n the maximum thickness of the sedimentary cover in the Perish Trough (16-2 0 km) and the crustal root (similar to 50 km) associated with TESZ:TTZ. (C) 1999 Elsevier Science B.V, All rights reserved.