REAPPRAISAL OF CHINESE LOESS PLATEAU STRATIGRAPHIC SEQUENCES OVER THELAST 30,000 YEARS - PRECURSORS OF AN IMPORTANT HOLOCENE MONSOON CLIMATIC EVENT

Through the establishment of radiocarbon chronozones relating common g eological events within lacustrine and eolian sediments from five prof iles representative of loess yuan (tablelands), river valley and north west margin features of the Loess Plateau, we propose a series of stra tigraphic divisions within the last 30 ka. The focus of this detailed study involves stratigraphic relationships contributing to evidence of Younger Dryas events, with the recognition of cold-dry, cool-wet and cold-dry periods represented within the Heiheze silt, Midiwan pest and Liushuwan eolian sand. The stratigraphic profiles reflect century-sca le fluctuations of the East Asian monsoons. The precursor events enabl e us to place the Pleistocene/Holocene boundary at 10,000 BP.