Upper mantle anisotropy at the transition zone of the Saxothuringicum and Moldanubicum in southeast Germany revealed by shear wave splitting

Details Upper mantle anisotropy at the transition zone of the Saxothuringicum and Moldanubicum in southeast Germany revealed by shear wave splitting Upper mantle anisotropy at the transition zone of the Saxothuringicum and Moldanubicum in southeast Germany revealed by shear wave splitting

Feb 2001

adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2001geoji.144..309p&link_type=abstract

Geophysical Journal International, Volume 144, Issue 2, pp. 309-319.

Astronomy and Astrophysics

Astronomy

6

Anisotropy, Moldanubicum, Saxothuringicum, Shear Wave Splitting, Sks Phases

Scientific paper

The main structures of the mid-European lithosphere, crossing Europe from the Iberian peninsula to the Bohemian Massif, are predominantly formed by the Variscan orogeny. To investigate the anisotropy of the mantle at the transition zone between the two Variscan units, the Saxothuringicum and the Moldanubicum, we carried out a field experiment in SE Germany in 1995-1996: 23 mobile broad-band stations were installed for 6 months in the Vogtland-Oberpfalz-Bavarian Forest area. The station profile crossed the suture zone of the Saxothuringicum and Moldanubicum near the KTB borehole (German Continental Deep Drilling Program). With a mean station spacing of about 10km, we intended to obtain a high lateral resolution of the anisotropy parameters and to resolve possible changes when passing the suture zone. The analysis of the observed birefringence of SKS phases shows E-W directions for the fast polarization. Therefore, the directions deviate only slightly from the strike of the Hercynian mountain belt and from the direction of the absolute plate motion in that region. Indications for the transition zone come from a rotation of the fast polarization direction from 86°+/-13° in the northern part of the profile (Saxothuringicum) to 110°+/-15° in the southern part (Moldanubicum) as well as from strong variations of the splitting parameters with respect to the azimuths of the incoming waves in the middle of the profile. We interpret these variations as an expression of a complex mantle structure formed either by several anisotropic layers with inclined symmetry axes in at least one layer or by a model consisting of inhomogeneous anisotropic layers. A comparison of the azimuthal variations of the splitting parameters in the middle of the profile with those observed at the Gräfenberg station GRA1-situated in the central part of the transition zone approximately 100km to the west-shows remarkable differences, which may reflect lateral variations in the direction and inclination of the symmetry axes in the transition zone even on a small scale. Both observations-the change in the fast polarization direction from the northern to the southern part as well as the variations with respect to different azimuths in the middle of the profile-suggest that the transition zone between the Saxothuringicum and the Moldanubicum continues down into the upper mantle.

Affiliated with

Also associated with

No associations

Rating

Upper mantle anisotropy at the transition zone of the Saxothuringicum and Moldanubicum in southeast Germany revealed by shear wave splitting does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Upper mantle anisotropy at the transition zone of the Saxothuringicum and Moldanubicum in southeast Germany revealed by shear wave splitting, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Upper mantle anisotropy at the transition zone of the Saxothuringicum and Moldanubicum in southeast Germany revealed by shear wave splitting will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-1211362