Late Holocene Sedimentation Dynamics in the Lake Ulaan Basin, Southern Mongolia: A History of a Playa Lake 

Abstract

Sedimentation dynamics in the Lake Ulaan basin located in the northern margin of the Govi region, southern Mongolia show high sedimentation rates of 11.8–22.7 cm/ka in the eastern part of the basin and low rates of 3.3–5.8 cm/ka in the western part during the late Holocene. The eastern and western parts of the lake have been strongly influenced by fluvial and aeolian activities since the arid late Holocene. However, fluvial sediment input was more significantly recorded in the eastern part. Aeolian deflation has been prevailing throughout the lake bank recently. Lake Ulaan reached its maximum extent before the early Holocene (Sternberg and Paillou, 2015; Holguin and Sternberg, 2016) with a water depth of ~43 m (Lehmkuhl et al., 2018a). After the early Holocene, Lake Ulaan started to decrease its area, and the drop of the lake level intensified since the middle Holocene. In the late Holocene, the лйоупы western and eastern parts were initially exposed to wind deflation at 2.7–3.2 cal. ka BP and the aerial exposition continued at 0.6–1.3 cal. ka BP. In the Anthropocene, Lake Ulaan has rapidly shifted into a playa lake condition during the last five to six decades, and it has become an open-source area of dust generation blown out by the westerly winds.