Seismic evidence for whole lithosphere separation between Saxothuringian and Moldanubian tectonic units in central Europe

Abstract

The Bohemian Massif is part of the Variscan belt of central Europe. We carried out a high resolution mapping of lithospheric thickness beneath central Europe by investigating 264 teleseismic events recorded at 80 broad band stations in the western Bohemian Massif with the method of S receiver function analysis. A negative phase beneath the Saxothuringian and northeastern Teplá-Barrandian units at about 9-10 s before the S onset is interpreted as caused by the lithosphere-asthenosphere boundary (LAB) at 80-90 km depth. In the Moldanubian unit, the negative phase occurs at 13-15 s before the S onset, corresponding to lithospheric thickness of 120-130 km. The boundary between the domains is oriented E-W and probably marks the northern extension of Moldanubian lithosphere. The Moho also deepens from the Saxothuringian to the Moldanubian unit. The observed crustal/lithospheric domains could represent two distinct microplates with a relatively sharp boundary cutting through the whole lithosphere. Copyright 2007 by the American Geophysical Union.