ПЛЕЙСТОЦЕНОВЫЕ КАНАЛЫ СТОКА В ЮЖНОЙ ЧАСТИ КЕЛЬТМИНСКОЙ ЛОЖБИНЫ (КАМСКО-ВЫЧЕГОДСКОЕ МЕЖДУРЕЧЬЕ)

The article discusses the origin of runoff channels in the Keltma hollow (Keltma spillway), which is a through valley between the Vychegda and Kama basins. The research conducted using field (GPR survey, cores drilling, radiocarbon, spore-pollen analysis) and remote sensing (interpretation of satellite images, calculation of topographic wetness index) methods that made possible to determine the time and speculate on the causes of their formation. The location of runoff channels on the Kalininian (Early Weichselian, MIS 4–5) lake terrace surface and their traces on the surface of the Kama first terrace limits their age to a period of no more than Ostashkov (Late Weichselian, MIS 2) epoch. The same is indicated by the location of these formations hypsometrically above the South Keltma, Timsher and Pilva valley systems, the formation of which falls on the period after the completion of the LGM 18–13 ka. The probability of relict landforms formation under the periglacial conditions of the Ostashkov stage is indirectly confirmed by the results of pollen studies from the in-fill of the largest channel – the so called Large Terrace Hollow. Scour formation in the aeolian plume body is proposed as the most likely model for the runoff channels formation in the Keltma hollow. The aeolian sand plume served as a dam of a reservoir filled with icedammed waters from the Vychegda basin.