Abstract
The presented research examines the structural-geomorphological features of the Razgrad block morphostructure. The boundaries and main parameters of the visible part of the morphostructure are determined: area of the hypsometric belts, slope of the slope surfaces, configuration of the hydrographic network, as well as the values of the horizontal and vertical dissection of the relief. An analysis of the geological-tectonic features (rock complexes, tectonic disturbances, etc.) and geophysical characteristics (geophysical fields, transitions, gravity anomalies, etc.) of the Razgrad block morphostructure was performed. During the field research, characteristic elements of the landforms were mapped: erosional slopes, leveled surfaces and river terraces. The Razgrad morphostructure is defined as a relatively independent block in the parietal region of the North Bulgarian arch swelling. It was established that it was placed on an old Permian-Triassic block bounded and uplifted by two sub-parallel faults in the Upper Jurassic-Valangian carbonate complex. Lower Cretaceous, Pleistocene and Holocene rock complexes are described in the Razgrad morphostructure. In the final part of the study, a scientifically based conclusion was made that the morphostructural development of the Razgrad block morphostructure went through the following stages: Donеogene, Neogene, Pliopleistocene and Holocene.