• East Asian monsoon;
  • Holocene;
  • lake sediment;
  • Mongolia;
  • paleoclimate


A 5.88-m-long core taken from Lake Ulaan was studied for high-resolution paleoclimatic changes during the last 17 000 years. The core sediments are divided into three units based on grain-size distribution: unit 1 (top to 392 cm depth, covering the last 11 200 years), unit 2 (392–530 cm, 11.2–15 ka) and unit 3 (530–588 cm, 15.0–16.7 ka). These sediments were transported by local westerly winds (units 1 and 3) and fluvial processes (unit 2). Based on major element compositions and geological setting of adjacent areas, provenance of unit 1 sediments was interpreted to be the Lake terrane, and that of unit 2 to be the Idermeg terrane. Unit 3 sediments were derived from the Gobi Altai terrane. The records of total organic carbon, C/N ratio and weathering intensity suggest that paleoclimate in the source area of Lake Ulaan sediment was most humid during the Early Holocene, humid during the mid-Holocene and dry in the Late Holocene. The decrease of humidity through the Holocene is a typical characteristic of the East Asian monsoon region. Comparison with lacustrine records of other Mongolia regions suggests that the northern boundary of East Asian summer-monsoon influence could have been located further north than previously assumed. Copyright © 2013 John Wiley & Sons, Ltd.