New data on the structural geomorphology of the coastal plains and continental shelf of east arctic seas of the USSR

Evolution of Relief Along the Arctic Coast of Northeast Asia During the Cenozoic

“…This is explained by the occurrence at this time, over a large part of northeast Asia, of the last phase of neotectonic movements, as a result of which uplift considerably equalized the eustatic rise of sea level. It must be stressed that the highest contrast of tectonic movements was in the region of rift activation in the northern Verk hoyansk area [7] and the zone of the western Poluosnyy and Sellyakh-Shanginskiy fault system [10]. The overall arched uplift of the surface that they caused in this sector of the shelf region moved the shoreline far back in the eastern part of the Laptev and western part of the East Siberian sedimentation basins.…”

“…The ending of midQuaternary deposition was related to the last phase of neotectonic movements, which was ex tensively manifested over the northeastern USSR, beginning at the end of the Middle Pleistocene. The most intensive movements encompassed the area of rift activation in the northern Verk hoyansk region and along the western Poluosnyy system of faults [7,10]. On the Primor'ye lowland they caused considerable warping of the surface of the polygenetic accumulative plains, reaching amplitudes of as much as 100 m, and partial exhumation of the buried denudational relief.…”

“…The greatest subsidence first occurred in the East Siberian sector, linked to the older Amerasian basin of the Arctic Ocean, which was already in existence in the Early Cretaceous [13], as is reflected in the distinctive overall morphostructure of this part of the shelf [10]. In this part of the shelf region the sea had reached the present boundaries of today's land as early as the Oligocene, invading far into the continental interior along longitudinal depressions on the margins of the Anyuy-Medvezh'iy arched-block uplift [6].…”