Grain Size Characteristics of the Holocene Peat Sediment in Eastern Tibetan Plateau and Its Paleoclimatic Significance

Key words: 
• peat /
• grain size /
• ash content /
• plaeoclimate /
• winter monsoon

Abstract: Based on the comparison of the grain size characteristics of the Holocene peat sediment in eastern Tibetan Plateau with that of typical eolian sediments, fluvial sediments, and lacustrine sediments, the authors find that the grain size characteristics of peat sediment in the study site closely resemble that of eolian sediments (e.g. loess and paleosol), but differ from that of fluvial sediments, and lacustrine sediments, no matter in the distribution curves or the cumulative curves. The discriminant parameter for the sedimentological environment determining, calculated by the statistical parameters of grain size, also shows the same result. So, the ash content in peat sediment can be used as a proxy to indicate the winter monsoon intensity, higher ash content shows stronger winter monsoon, and the vice versa.