Abstract
Thermokarst lakes exert a significant influence on the formation of the Kolyma Lowland relief, affecting the high-ice sediments of the yedoma. Thawing and compaction of the ice complex result in the formation of taberal sediments. An outcrop of lacustrine and taberal sediments (31 m) is traced on the right bank of the Bolshoy Khomus-Yuryakh River. The discovery of a mammoth skull, with tusks preserved in the alveoli, in lacustrine sediments dated to >49,000 years ago, and palynological data permit to distinguish pollen zones of isotope stages (MIS) 5, 4, and 3. A distinctive feature of the taberal sediments is pseudomorphs on ice wedges with an abundance of large alder and birch shrubs and larch trunks, indicating the formation of pseudomorphs in isotope stage 5 (MIS5) as a result of the activation of lacustrine thermokarst. At that time, the Kolyma Lowland was dominated by larch forests with dense undergrowth of shrubby alder, birch, and willow.