Formation of defused stress areas in the Earth's crust of the Kola region and associated environmental risks in capital construction

This work has been carried out using methods of numerical modeling to detect weakened zones in the basement of the region in regard to the construction and economic human activities. For this purpose, we have constructed quantitative models of the stressed-deformed state of the Earth's crust in the region considering its evolution. Determined for the first time are the structures that accumulated a tectonic-magmatic activity and produced mobile-permeable zones in the Precambrian mainly. For the first time, we have found an interrelation between localities of deep fractures (activation areas) and the stressed-deformed state of the Earth's crust caused by the impact of regional tangential stresses. Most of mineral deposits are located within the identified weakened zones of the geological basement. Economic activity of the population is concentrated there, which affects the ecological situation in the region. In addition, most of the territory where the mobile-permeable areas are detected in the basement is overlapped by known seismogenic zones of the region. Consequently, seismic events with an increased level of magnitude are more often generated in these areas due to the detente of interblock stresses in the geological environment. The provided research indicates the necessity of studying the general geological structure of the region and identifying setting areas of ancient deep deformation structures in design and construction of the major industrial, road, hydraulic engineering and other objects