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Abstract: We present a new thermal and rheological model of the European lithosphere (10°W–35°E; 35°N–60°N), which is based on a combination of recently obtained geophysical models. To determine temperature distribution we use a new tomography model, which is principally improved by an a-priori correction of the crustal effect, by using EuCRUST-07, a new digital model of the European crust. The inversion approach is similar to those used in previous studies, but the employment of a more robust tomography model essentially improves the result. The uppermost mantle under western and central Europe is mostly characterized by temperatures in a range of 900°–1100°C, with the hottest areas corresponding to the basins, which have experienced recent extension (e.g. Tyrrhenian Sea and Pannonian Basin). By contrast, the mantle temperatures under eastern Europe are about 550°–750°C at the same depth and the minimum values are found in the northeastern part of the study area. The new temperature estimates are used to trace the lithosphere–asthenosphere thermal boundary, as a depth of the isotherm of 1200°C. The lithospheric thickness is less than 100km beneath the hottest part of western and central Europe, while the maximum values are observed beneath the East European Platform (200–230km), the Alps and the Dinarides–Hellenic Arc (150–180km). EuCRUST-07 and the new thermal model are used to calculate the strength distribution within the European lithosphere. Differently from previous estimates, the new model adopts lateral variations of lithology and density, which are derived from the crustal model. According to these estimates, in western and central Europe the lithosphere is more heterogeneous than in eastern Europe, the latter being generally characterized by higher strength values. These strength variations are also in a good agreement with other geophysical characteristics of the lithosphere such as residual mantle gravity anomalies. [Copyright &y& Elsevier]

Abstract: Tectonic studies show that intraplate Europe is more active than might be expected from its tectonic setting. We employ integrative analysis of various datasets, which provides new understanding of deformation processes in response to different types of loading. A 3D strength model of the lithosphere, which is based on existing structural, compositional and thermal models of the lithosphere, forms the basis for this study. Boundaries of the crustal layers are determined from existing seismic data. Constraints on the thermal structure of the lithosphere are obtained from heat flow studies and upper mantle seismic tomography. The calculated strength distribution is used to quantify spatial variations in effective elastic plate thickness (EET) of the European lithosphere. A comparison with seismic and geodetic strain rates provides new insights into the localization of intraplate deformation. Another important indication of lithospheric strength is provided by the residual mantle gravity anomalies obtained after removing the crustal contribution from the observed gravity field. We have found significant spatial variations in rigidity within the Central and Western European lithosphere, in contrast with a more uniform strong lithosphere of the East European Platform. These variations are consistent with differences in the density structure of the mantle lithosphere reflected in mantle gravity anomalies. Western Europe is mostly characterized by negative mantle gravity anomalies and low EET values (generally≤20 km), whereas the opposite is true for Eastern Europe. Large differences exist also for specific tectonic units: e.g. a pronounced contrast in lithosphere properties is found between the strong Adriatic plate and the weak Pannonian Basin area, as well as between the Baltic Shield and the North Sea rift system. We demonstrate that the European Cenozoic Rift System (ECRIS), which is characterized by low EET values and negative mantle gravity anomalies, localizes neotectonic deformation manifested by relatively high geodetic and seismic strain rates. [Copyright &y& Elsevier]

Abstract: Potential gravity theory (PGT) predicts the presence of significant gravity-induced horizontal stresses in the lithosphere associated with lateral variations in plate thickness and composition. New high resolution crustal thickness and density data provided by the EuCRUST-07 model are used to compute the associated lateral pressure gradients (LPG), which can drive horizontal ductile flow in the crust. Incorporation of these data in channel flow models allows us to use potential gravity theory to assess horizontal mass transfer and stress transmission within the European crust. We explore implications of the channel flow concept for a possible range of crustal strength, using end-member ‘hard’ and ‘soft’ crustal rheologies to estimate strain rates at the bottom of the ductile crustal layers. The models show that the effects of channel flow superimposed on the direct effects of plate tectonic forces might result in additional significant horizontal and vertical movements associated with zones of compression or extension. To investigate relationships between crustal and mantle lithospheric movements, we compare these results with the observed directions of mantle lithospheric anisotropy and GPS velocity vectors. We identify areas whose evolution could have been significantly affected by gravity-driven ductile crustal flow. Large values of the LPG are predicted perpendicular to the axes of European mountain belts, such as the Alps, Pyrenees–Cantabrian Mountains, Dinarides–Hellenic arc and Carpathians. In general, the crustal flow is directed away from orogens towards adjacent weaker areas. Gravitational forces directed from areas of high gravitational potential energy to subsiding basin areas can strongly reduce lithospheric extension in the latter, leading to a gradual late stage inversion of the entire system. Predicted pressure and strain rate gradients suggest that gravity driven flow may play an essential role in European intraplate tectonics. In particular, in a number of regions the predicted strain rates are comparable to tectonically induced strain rates. These results are also important for quantifying the thickness of the low viscosity zones in the lowermost part of the crustal layers. [Copyright &y& Elsevier]