The Structure of the Basement of the near-Laptev Part of the Eurasian Basin According to Geological and Geophysical Data

The near-Laptev part of the Eurasian basin is an area of transition from modern spreading to intraplate rifting. We propose an approach to the construction of a 3D model of the basement of the near-Laptev part of the Eurasian basin based on all currently available geological and geophysical data. The structure of the acoustic basement of the Eurasian basin consists of alternating troughs and highs in cross-section. The sparse seismic data do not allow us to directly trace the strike of these structures, however, they can be correlated with linearity established by gravity and magnetic data and related to the sequential opening of the basin. For the near-Laptev part of the Eurasian Basin, where the linearity is no longer traceable from magnetic data, we propose to determine the strike of the basement structures on the basis of a seismic stratigraphic analysis. The new 3D model of the acoustic basement in the studied area provided the basis for a tectonic scheme of the entire Eurasian Basin. The model reflects the main stages of the basin development: continental rifting for up to 56 Ma, normal spreading for 56–45 Ma, ultraslow spreading for 45–34 Ma, and ultra-ultraslow spreading for 34–20 Ma. The southern part of the study area is overlain by sedimentary cover with an age of 20 Ma and younger, which is associated with the cessation of spreading here no later than 20 Ma ago.