Geological Interpretation Of The Regional Deep Seismic Reflection Profile In Eastern Rhodope Mountain (South Bulgaria)

The deep seismic profiling crossing the structures of Eastern Rhodope Mountains (South Bulgaria) started in 1993 and it was finalized in 1995. The used COCORP Technique for data acquisition along the 131 km nonlinear cross-line IR1 and the methods for data processing were published some years later. The geological and tectonic interpretations were based entirely on qualitative considerations of the seismic reflection time-scaled cross-section. The present study uses the transformed in kilometric scale deep reflection picture of the cross-section for quantitative interpretation of the geometrical characteristics of the crossed tectonic structures and their geological infilling. The recent data from the geological mapping in scale 1:50 000 is taken into account. Important information has been acquired for the deep characteristics of two tectonic structures - Central Rhodope Unit and East Rhodope Unit. Two types of Earth’s crust are identified – continental in the western part and sub-oceanic to the eastern. An Alpian obduction of the sub-oceanic crust on paleo-continental margin is deduced. The clear lamination of the seismic reflections, as well as inner “discordances” and surfaces of shearing bellow the Paleogene cover of Momchilgrad Depression, permitted the identification of 5 mega trustsheets. Intrusive bodies and fault zones are also determined.