Mid to late Holocene climate evolution of the Lake Telmen Basin, North Central Mongolia, based on palynological data

Palynological and sedimentological data from Lake Telmen, in north-central Mongolia, permit qualitative reconstruction of relative changes in moisture balance throughout the mid to late Holocene. The climate of the Atlantic period (7500-4500 yr ago) was relatively arid, indicating that Lake Telmen lay beyond the region of enhanced precipitation delivered by the expanded Asian monsoon. Maximum humidity is recorded between similar to4500 and 1600 cal yr B.P., during the Subboreal (4500-2500 yr ago) and early Subatlantic (2500 yr-present) periods. Additional humid intervals during the Medieval Warm Epoch (similar to1000-1300 A.D. or 950-650 ago) and the Little Ice Age (1500-1900 A.D. or 450-50 yr B.P.) demonstrate the lack of long-term correlation between temperature and moisture availability in this region. A brief aridification centered around 1410 cal yr B.P. encompasses a decade of cold temperatures and summer frost between A.D. 536 and 545 (1414-1405 yr B.P.) inferred from records of Mongolian tree-ring widths. These data suggest that steppe vegetation of the Lake Telmen region is sensitive to centennial- and decadal-scale climatic perturbations. (C) 2003 Elsevier Science (USA). All rights reserved.