Lake Yamal, an ice-dammed megalake in the West Siberian Arctic during the Late Pleistocene, similar to 60-35 ka

We here reconstruct giant Lake Yamal that existed ca. 60-35 ka BP across the northern Yamal Peninsula and parts of the Kara Sea shelf in the West Siberian Arctic. Its sediments build most of the landforms in the area and are represented by a wide range of offshore and delta sedimentary facies containing an assemblage of fresh-water diatoms. The lacustrine sequence mostly consists of deep-water and prodelta clayey-silty rhythmites and deltaic sand and silt. The lake was dammed by the Middle Weichselian Kara Ice Sheet and, presumably, occurred shortly after the regression of the Early Weichselian postglacial coldwater sea. The lake sediments are associated with alluvium of the ancient Ob River, which flowed into the lake and accumulated spacious delta. The position of the lake shore is quite accurately defined in the northern Yamal Peninsula, whereas there are no reliable data to outline its distribution area within the Kara Sea shelf. The Lake Yamal sediments rest directly on the cold-water marine Morzhovka Formation with optically stimulated luminescence (OSL) ages between 90 and 60 ka BP. The lake deposits are overlain by aeolian cover sand dated by OSL to 20-16 ka BP. (C) 2022 Elsevier Ltd. All rights reserved.