For the construction of the maps on sheet numbers T-49-52 and T-53-56 of the State Geological Map of the Russian Federation with a scale of 1:1 000 000, various data was gathered and analyzed on the geological structure of the Laptev Sea continental margin and the adjacent part of the deep-ocean basin of the Eurasian sub-basin of the Artic Ocean. The geology of this part of the Eurasian Continental Margin is unique because of the presence of the Gakkel Ridge, the slowest spreading ridge in the world system of the mid-oceanic ridges, which encroaches and ends here. In order to create the conditional topographical basis for the State Geological Map with a scale of 1:1 000 000, a detailed bathymetric map of this region was constructed by the GUNiO MO. Comprehensive analysis of the original bathymetry, seismoacoustic data and MCS profiling, as well as information of modern seismic activity of the Gakkel Ridge led us to discover the main features of its end in the Laptev Sea. Dissected by post-Miocene faults, the very thick sediment that completely fills the rift valley, as well as the poor definition in the modern relief of the Gakkel Ridge are evidence of the impulsive character of its development with shorter periods of tectonic activity followed by longer periods of tectonic inactivity. The character of the distribution of seismic complexes of sedimentary cover shows that the pectinal part of the ridge is dome-shaped with a rising of the lower seismic complexes from the Nansen and Amundsen Basins towards the Rift Mountains. This is evidence of the complicated multi-phased history of the encroachment of the oceanic rift within the borders of the Continental Margin.

Fig. 6, references – 28.