Crystalline crust examined along the seismic profile LT-7 is subdivided into four blocks separated by distinct vertical fractures. The northeastern block belongs to the East European Craton (Baltica). Its three-layer structure is similar to that of the Svecofennian crust farther to the northwest. The southeastern block reveals typical, two-layer Variscan crust. Both central blocks have a peculiar structure not comparable with the crust of the Danish and North German areas: two lower layers, with velocities identical or close to that of the cratonic lower and middle layers, are extremely thin, and an upper layer, 8–11 km thick, shows surprisingly low velocities. This upper layer probably represents the folded and weakly metamorphosed Lower Palaeozoic sequences, although the connection with undeformed epicratonic cover cannot be excluded. Significant differentiation of crustal types in different segments of the Trans-European Suture Zone favours the concept of tectonostratigraphic terranes which collided with Baltica.