Farfuliak L. Deep structure of the western part of the Scythian microplate based on present seismic data

The thesis is devoted to study the deep structure of the western part of the Scythian microplate (SM) based on data of deep seismic sounding (DSS) method. New seismic boundaries have been revealed according to the wide-angle refraction and reflection (WARR) seismic experiment along the DOBRE-5 (2011) profile. The inclined seismic boundary (ISB) was allocated as a result of geological interpretation of 2D seismic model along the DOBRE-5 (2011), which is associated with a joint zone of East European Platform (EEP) (as part of the Eurasian plate) with SM. It is shown that ISB is likely Late Paleozoic-Early Mesozoic North-Crimea suture in the SM crust. It is estimated that ISB has an average angle of 17 ° dip to the south and was formed in conditions of north-north-west - south-southeast compression. The analysis of the P-wave velocity distributions in seismic models of profiles DOBRE-5 (2011), DOBRE-4 (2009), DOBRE-2 (2007) and VRANCHEA-99 shows that SM has a three-layered structure of the crust similar to that observed for the EEP crust. Local seismicity of the ISB and SM may indicate the presence of on-going processes of lithospheric folding/buckling and related faulting in the crust of the suture zone of East European Platform with SM. A mechanism of propagation of tectonic deformations acts from active southern boundary of the SM, where it locates at the boundary with the Alpine fold-and-thrust belt, far away within the intracontinental areas of the EEP.