Paleogeographical conditions and possible migration routes of Paleolithic humans from the western foothills of the Urals to the valley of the Lower Ob river

Geological and geomorphological analysis of the Ural Range and adjacent territories has made it possible to establish paleogeographical conditions for migrations of Paleolithic humans across the Ural Mountains. Based on the MERIT DEM digital model resampled to 70 x 70 m resolution, trend surface was created using the method of the sliding window with the radius of 10 km. Then the trend was deducted from the original DEM, resulting in raster surface with pixels containing the value of vertical deviation from the relief trend. Pixels located below the trend surface were selected from the raster surface and corresponded to valleys. After that the slopes with inclination angle under 4 degrees were selected from the contours of the valleys. These pixels corresponded to the required through valleys. Thereby, through valleys with flat and wide bottoms across the Ural Mountains, suitable for long journeys of family groups of Paleolithic people including the elderly and children, have been identified. In addition, secondary valleys with narrower bottoms and slopes under 8 degrees, connected with the main valleys by through passages have been identified. In the Lower Ob River region (the part from Kazym-mys to Pitlyar), through valleys across the Urals join two left tributaries of the Ob River - the Voikar and Sob Rivers. To the north, in the Arctic Urals, a though valley connects with the Shchuchya River. To the south, a number of through valleys join the Severnaya Sosva River basin opposite the Kazym River. Further to the south, several through valleys join the Tavda River basin opposite the Irtysh River. Thus, there were potential migration routes available in the Northern Urals, which makes Northern Urals a very promising region as a starting point for peopling the north of the Ob valley. In 2016-2019, Paleolithic artifacts have been found on the surface in the right bank area of the northern Ob River valley.