Abstract:
The Botev Vrah Thrust covers a great part of Central Balkanides on the
territory of Bulgaria and it is of regional importance for the Late
Alpine evolution of this area.
The lecture will be focused on the geometry, architecture and kinematic
features of the thrust. Along the thrust zone numerous imbricate
structures are documented. Two types of thrust contacts are
distinguished according to the composition of the footwall. Meso- and
microstructural characteristics of tectonites and estimation of
deformation related to thrust emplacement in both hanging wall and
footwall will be discussed. The observed structural features and
geochronological data obtained give evidence that the Botev Vrah Thrust
represents a brittle fault zone formed in shallow crustal levels at
temperatures 120–250ºC.
The analysis of the data strongly suggests that the Botev Vrah Thrust is
an example of thick-skinned tectonics, developed during Paleocene–Middle
Eocene period. On the basis of fission-track dating and structural
studies thermochronological reconstruction of the Central Balkanides
tectonic evolution will be discussed.