TECTONICS, VOL. 10, NO. 2, PAGES273-286, APRIL 1991 LARGE-SCALE THIN-SKINNED TECTONICS IN THE EASTERN BOUNDARY OF THE BOHEMIAN MASSIF Pavel Cizek Central Geological Survey, Brno, Czechoslovakia Cestmir Tomek Geofyzika, s. e., Brno, Czechoslovakia ADstract. Two new seismic reflection profiles and a deep borehole re- veal thin-skinned thrusting on the easternmost part of the Rheno- Hercynian zone of the Variscan belt of Europe. Above Precambrian Brunnia basement the profiles show three different seismic zones within the compressed Palaeozoic sedimentary section. The borehole data suggest that the lower zone is a deformed II II paraautochthonous Brunnia basement covered by Upper Devonian and Lower Carboniferous shelf carbonates with numerous local overthrusts. This zone is overthrust by the uppermost seis- mic zone of Lower Carboniferous Culm flysch wedge and in the west by the eastward dipping zone. This interven- ing seismic zone on the east end of Copyright 1991 by the American Geophysical Union. Paper number 89TC03241. 0278-7407/91/89TC-03241510.00 the profiles is a foreland dipping thrust sheet of another Culm flysch complex (mainly Horni Benesov Forma- tion) , or seismic crocodiles in the sense of Meissner (1989). Inverted metamorphism between the Culm flysch and the Brunnia shelf sequences en- countered in the well Potstat-l, and strong slaty cleavage in the inter- vening zone, suggests that the upper zone is allochthonous, heaving been thrust from deeper levels tens of kilometres eastward over carbonates. Imbrication of the carbonates as part of the footwall suggest relatively strong coupling between the Palaeo- zoic sediments and underlying base- ment at the time of thrusting. INTRODUCTION A thrust and nappe tectonic style within the Variscan belt [Matte, 1986] has been recognized