Lithospheric structure across the Trans-European Suture Zone in NW Poland based on gravity data interpretation

Abstract

We provide an analysis of geophysical and geological data from the Baltic segment of the Trans-European Suture Zone (TESZ). The construction of structural and density maps of the Zechstein-Mesozoic-Cenozoic complex has allowed identification of anomalies of basement orgin. As a result of interpretation of these anomalies, major structural elements of the lithosphere have been characterised. According to gravity modelling the crustal structure is more complicated than shown on velocity model along refraction and wide-angle reflection profile LT-7. Long-wavelength anomalies have been modelled in terms of lateral heterogeneity within the lower crust and upper mantle. In order to achieve a match between the observed and calculated gravity effects, it was necessary to assume dense upper mantle beneath the TESZ. Gravity data also indicate the presence of high-density bodies in the upper crust, and a complex transitional zone between crust and upper mantle in the TESZ.