Home – Home – Jornals – Russian Geology and Geophysics 2001 number 4

The highest and longest ridges of the East Yakutian mountainous province exist on its periphery as the Upper Yana system in the west and the Chersky and Moma systems in the east. Northward, the ridges give way to the Primor'ye lowlands that grade into the Laptev Sea shelf separated from the Eurasian ocean basin by the continental slope. The ridges of the Upper Yana system make an asymmetric arch dislocated by younger normal faults. The system of Chersky and Moma ridges is likewise an arch cut with strike-parallel rift basins (Moma, Upper Selennyakh, etc.). The Cenozoic fill of the basins adjacent to the ridges provides evidence that rapid uplifting of the latter started in the Oligocene. Doming in the Late Miocene-early Pliocene was accompanied by compression, which produced imbricated thrusts with horizontal displacements of up to several kilometers. In the Late Pliocene-Early Pleistocene, the crust of the region experienced a large-scale extension responsible for the opening of the Moma rift and normal fautling in the Upper Yana ridge.
he growth of mountain ridges in Eastern Yakutia may be related to the interaction of the Eurasian and North American plates in the Cenozoic and the opening of the Arctic Eurasian ocean. Multiple changes in the position of the plates' poles through the Cenozoic caused alternation of extension and compression regimes. The opening of the Eurasian basin and the formation of mountain ridges in Eastern Yakutia were, apparently, nearly coeval geodynamic events.