A three-dimensional density model of the European lithosphere: I.

This paper consists of two parts. The first part addresses the structure an d density parameterization of a 3-D model of the crust beneath the European continent and part of the North Atlantic. The model consisting of two regi onal layers of variable thickness (sediments and consolidated crust) is app roximated on the basis of a generalized velocity model of the crust in the form of structural maps for the main seismic horizons: the surface of the s eismic basement and Moho. The internal heterogeneity of the layers was take n into account as a lateral variation in the mean density, depending on the types of geostructures. This variation was determined by using correlation dependences of the density increasing with depth (for sediments) and gener alized conversion functions between the density and velocity. In the sea, t he model was supplemented by a seawater layer The modeling provided the ove rall model effect and residual anomalies obtained by subtracting the model effect from the observed field. The model as a whole and its individual str uctures were isostatically adjusted. The continent is clearly seen to divid e into two large blocks: the Precambrian East European platform and Western Europe, with residual anomalies ranging from -100 to -150 mGal. The blocks are separated by the Tornquist-Teisseyre zone, characterized by a gradient of residual anomalies. The East European platform, at the center of which a vast positive anomaly is revealed on the Russian plate, is bounded to the west and east by positive residual anomalies. Western Europe and the Medit erranean are characterized by negative residual anomalies over sedimentary basins and by positive anomalies over Alpine orogens. The second part of th is paper compares the modeling results with data obtained by other methods (primarily, seismic tomography and the geothermal method) in relation to up per mantle heterogeneities and will interpret the results of this work.