Technology of Mapping of Volcanic-Sedimentary Strata in a Complexly Dislocated Terrigenous Structure according to Seismic and Magnetic Exploration Data (Pechora Sea)

The geological efficiency of seismic exploration and, as a result, the reliability of structural constructions in areas of intense tectonic dislocations (normal, reverse and thrust faults) is significantly reduced. At the same time, it is in such areas, that the presence of lithostratigraphic complexes contrasting in density or magnetic properties in the section and the abundance of subvertical boundaries provide prerequisites for the successful use of potential field methods (gravity exploration, magnetic exploration) to verify and supplement the structural interpretation of seismic exploration data. The paper presents the technology of complex interpretation of magnetic and seismic exploration data, tested on one of the objects of the Pechora Sea. In the course of the research, the connection of local magnetic anomalies with the seismic structural plan was established, which made it possible to identify and trace a magnetically active complex in the sedimentary strata with parameters typical of volcanogenic sedimentary rocks, weakly contrasting in seismic records. As a result of 3D modeling, the morphology of the roof and the base of the magnetic layer were determined, and the three-dimensional distribution of magnetization was calculated. It is proved that the sources of local magnetic field anomalies, a priori considered as isolated intrusive massifs, are associated with the distribution of magnetization within a single stratified volcanogenic-sedimentary strata. The obtained result was used in the construction of an updated geological and geophysical model. The developed technology is recommended as one of the promising approaches for building seismomagnetic models in similar physical and geological situations.