Structural evolution of the eastern Balkans (Bulgaria)

摘要: Abstract The Balkans are an E-W trending thrust belt mainly of Palaeogene age, generated by a left-lateral transpression with maximum stress-oriented N30°E. transpressive nature the may be deduced from en echelon pattern folds and thrusts which is due to oblique shortening respect pre-existing Mesozoic crustal anisotropies between Moesia Platform Basin. front eastern marked Chudnite Skali-Ajtos thrust. During Neogene Quaternary were inverted right-lateral transtensional tectonics cross-cut dismembered belt. main segment southern margin (e.g. Emine Line). steep faults disconnected planes Srednogorie south. Grabens in general asymmetrical, master dipping 80-40° south-westward probably flattening into middle crust. structural evolution also traced Black Sea, but trends gradually change trend NW-SE strike, indicating pure compression more recent extension inverting cross-cutting compressive features. It interesting note that tensional or inversion not cylindrical; it exhibits undulations graben transfer controlled fabric. their continuation Sea morphologically structurally deeper they plunge eastward south-eastward towards Sea. This both position de´collement thermal subsidence along continental margin.