Grain size profiles in the Chengdu Clay, eastern margin of the Tibetan Plateau: Implications for significant drying of Asia since ∼500 ka B.P.

Asian aridification reflects a combination of the uplift of the Tibetan Plateau and global cooling. Grain size analysis of the Chengdu Clay at the eastern margin of the Tibetan Plateau indicates a rapid increase of coarse fractions at around 500 ka, suggesting a significant drying event in the source region. Comparison with results from the Chinese Loess Plateau (CLP) indicates that this drying event occurred on a regional scale and may imply an important drying event in eastern Asia. We estimate that the rapid uplift of the Tibetan Plateau during the middle Pleistocene may be one of the most important causes of the significant drying in the area.