A new model for the pre-Permian basement of the Central Stara Planina Mountain

After more than 40 years break in the detailed studies of Central Stara Planina an extensive field research on the pre-Permian basement in the area was carried out. The newly gathered data require substantial modi_cation of the existing models. Within the basement we are distinguishing two pre-Variscan rock units: low-grade Lower Paleozoic complex and an associated metagranitoid suite (Ambaritsa suite). A large number of data indicate a prolonged and voluminous Variscan granitoid magmatism in the studied area. On the basis of the intensity and character of the solid-state overprint these magmatic rocks are subdivided into three categories: syn-kinematic (Karlovo-Ribaritsa suite), late-synkinematic (Kalofer suite) and post-kinematic granitoids (the Vezhen pluton, Anton and Rozino/Klisura granites). Also, the existence of migmatitic basement typical for Stara Planina is rejected and the structural data are consistent with intensive Variscan tectonism in the areas supposed to be part of the crust that was consolidated probably in the Cambrian.