LATE HOLOCENE PALEOCLIMATE ANALYSIS USING LAKE CORES FROM THE HOVSGOL AIMAG REGION OF NORTHERN MONGOLIA

The pattern of late Holocene climate change in Northern Mongolia remains poorly understood. The small, closed basin carbonate lakes of the Hovsgol Aimag area, however, contain a unique record of past climate change extending back several thousand years. Previous lacustrine sediment studies in the area have relied heavily on the analysis of fossil pollen and plant remains, reconstructions that often provide ambiguous paleoclimatic inferences. In June of 2003, seven short sediment cores were retrieved from three lakes (Sanjim Nuur, Asgat Nuur, Boorog Nuur) located in an area proximate to the present day taiga/alpine tundra transition zone, a glacial mountain valley on the northern edge of the Hovsgol Aimag. Through analysis of the retrieved lake cores, we are examining sedimentological (magnetic susceptibility, LOI), geochemical (d¹⁸O and d¹³C of biogenic carbonate, general lake water chemistry), and biological variables in an effort to reconstruct decadal to centennial-scale precipitation and evaporation (P-E) fluctuations in the region. The sediment core analyses will create a high-resolution accelerator mass spectrometry (AMS) ¹⁴C-dated record of late Holocene climate variability and improve our understanding of the future climate trends in Central Asia.