(1) Geophysical Institute, Academy of Science of the Czech Republic, Prague
The Trans-European Suture Zone (TESZ) is the most prominent tecto-geological boundary within Europe separating mobile Phanerozoic terranes in the western part from the Precambrian East-European Platform in the eastern part. Distinct changes of seismic anisotropy of the mantle lithosphere are related to this intra-continetal suture. The effect is observable in various wavelengths as well as seismic wave types. In the long-periond range, the radial anisotropy of surface waves differs distinctly in the lithosphere on both sides of the TESZ. In the short-period range of body waves, the P residual spheres detected changes in the lithospheric anisotropy related the various blocks around the TESZ as well. A passive teleseismic field experiment -TOR- traversing the northern part of the TESZ in Germany, Denmark and Sweden was conducted during 1996-1997. The array recorded data for teleseismic tomography of the upper mantle with a high lateral resolution, about few tens of km, including data for seismic anisotropy studies. Our analysis of shear-wave data recorded at broad-band stations during the field measurements aims at retrieving a 3D orientation of anisotropy around the TESZ and mapping lateral changes of the 3D orientation of anisotropic structures along the TOR antenna. An interpretation of the observed seismic anisotropy by the preferred orientation of olivine crystals results in a model of the mantle lithosphere characterized by plunging anisotropic structures. It is evident that different orientations of large-scale olivine fabrics on both sides of this major suture zone extend through the whole lithosphere.
Not available.