GEODYNAMIC AND TECTONIC EVOLUTION OF THE SOUTHEASTERN BOHEMIAN MASSIF- THE THAYA SECTION (AUSTRIA)

The tectonostratigraphy within eastern sections of the Bohemian Massif includes two different terranes. A Proterozoic terrane is composed of the Moravo-Silesian parautochthon, the Moravian nappe complex and the Moldanubian Variegated and Monotonous complexes. A Paleozoic terrane includes the Gfoh1 Gneiss and the granulite klippen. Both terranes are separated by an oceanic suture zone which is represented by the Letov ice ophiolite complex (Czech Republic) and the Raabs complex in Austri a. The Raabs structural unit is interpreted to represent a tectonic me lange of a dismembered ophiolite complex and metaandesites. The tecton ic evolution of the southeastern Bohemian Massif includes: (1) Paleozo ic extension predating late Variscan nappe stacking; (2) Variscan (c. 350-320 Ma) NE-directed nappe assembly by foreward propagation of thic k-skinned nappes, whereas individual thrusts initiated within differen t crustal levels; (3) post-stacking Variscan W-E extension which was r esponsible for penetrative nappe internal deformations; and, (4) dispe rsion of units by a system of dextral strike-slip faults and genetical ly related thrust- and normal faults. The kinematic history during Var iscan convergence is explained to have been related to oblique (dextra l) transpression of Proterozoic against Paleozoic terranes.