The deformation of continental crust during continental collision by folding and thrusting follows three types of structural styles: (1) in a true thin-skinned style only cover rocks are involved; (2) in the case of a thin-skinned basement-involved style, thin slabs of crystalline basement rocks are piled up into a nappe stack; (3) in a true thick-skinned style, the entire upper crust is involved in the deformation. In the Alps all three styles can be recognized. The Helvetic nappes and parts of the Penninic nappes exhibit true thin-skinned style tectonics. Triassic evaporites, Jurassic shales and Cretaceous marls acted as detachment horizons. Basement-involved thin-skinned tectonics is typical for the Penninic nappes in the core of the orogen. The thickness of the basement thrust sheets is controlled by the effects of Mesozoic rifting, by deep burial and heating of the subducting crust and by the presence of Late Palaeozoic structures. Thick-skinned style is observed in the more external parts of the orogen, the external massifs and the Southalpine nappe system. It occurred in the late phase of collision and involved the entire upper crust. The basal detachment occurred possibly along phyllonites generated by the breakdown of load-bearing feldspar. Considering the Alpine orogen as a whole, the lower crust deformed seemingly independently from the upper crust. The detachment of the cover units by thin-skinned tectonics occurred prior to thrusting related to basement-involved thin-skinned tectonics. Thrust faults of both types were overprinted by ‘post-nappe folding’.

The updated geological and potential fields data on the East European Platform margin in SE Poland confirm the existence of several regional units differing in Ediacaran to Silurian development: the Upper Silesian Block, Małopolska Block and Łysogóry Block. All the blocks are characterized by a distinct crustal structure seen in Vp velocity models obtained from the seismic refraction data of the CELEBRATION 2000 Programme. The first two units are interpreted as exotic terranes initially derived from Avalonia-type crust and ultimately accreted before the late Early Devonian. The Łysogóry Block is probably a proximal terrane displaced dextrally along the Baltica margin. The sutures between the terranes do not precisely match lateral gradients in Vp models. This is partly explained by a limited resolution of refraction seismic data (20 km wide interpretative window). Most of the difference is related, however, to a post-accretionary tectonism, mainly Variscan transtension–transpression. The latter processes took advantage of lithospheric memory recorded earlier as zones of rheological weakness along the former suture zones. The course of the East European Platform margin (= Teisseyre–Tornquist Zone) corresponds most likely to the Nowe Miasto–Zawichost Fault marking the NE boundary of the proximal Łysogóry Terrane.

This paper describes the results of seismic refraction investigations of the upper crustal structure in the area of Deception Island, West Antarctica, which were made during the Polish Antarctic Geodynamical Expeditions in 1979-80 and 1987-88. In the caldera and immediate vicinity of Deception Island a layer of unconsolidated and poorly consolidated young sediments of 1.9–2.2 km s−1 P-wave velocity was found. Velocities of 4.1–4.3 km s−1 were found in the depth interval from 0.6–1.3 to about 3 km. Lateral differences in upper crustal structure between the south-eastern and western sectors were identified. In the region between Deception and Livingston islands an inclined boundary with a velocity of about 6.1 km s−1 occurs. A deep fault zone dividing crustal blocks beneath Deception Island is associated with a prominent volcanic line within Bransfield Strait extending between Deception and Bridgeman islands.

Maps showing depth to the Moho, the 6 km/s and 7 km/s isovelocity surfaces and the thickness of the crust with a velocity greater than 7.0 km/s for the UK and surrounding continental crust have been generated from a compilation of wide-angle/refraction data. The data show that the crust beneath northwestern Scotland is thinner and of higher velocity than that beneath southern Britain. The lower crust beneath the East Irish Sea and parts of the southern North Sea is formed from thick layers of high velocity rock. The lateral extent of these layers cross-cuts the downward projection of major structures mapped at the surface. This suggests that the major structures do not bound regions of lower crust with contrasting properties at depth. Instead these structures may be overprinted by modification of the lower crust, for example, by magmatic underplating, which is not observed directly at the surface. Mapped variations in crustal thickness do not mirror the variations in surface topography, which appears to contradict the view that the crust is in Airy isostatic equilibrium.