Abstract:

The study was to clarify the events of monsoon climate recorded by the palaeovegetation, using the results of pollen analysis, organic carbon δ13C, together with high-resolution 14C dating in the desert-loess transition zone for the last 13 ka BP. The palaeovegetation went though in the order of 9 periods viz.:desert-grassland,steppe,semi-desert,humid-grassland,desert,sparse-wood-grassland, desert-grassland, grassland, and desert grassland. The semi-desert, humid-grassland, and desert corresponded with the Younger Dryas events of cold-dry, cool-humid, and cold-dry climate after the end of the last glaciation. The optimum of the Holocene and other humid period between 4.5-3.5 ka BP were of high significance in research area.

沙漠/黄土过渡带13 Ka BP 以来季风演化的古植被记录
李小强¹ 周卫建¹ 安芷生¹ 董光荣²

（1. 中国科学院黄土与第四纪地质国家重点实验室，西安710054；2.  中国科学院兰州沙漠研究所，兰州730000）

摘要：利用花粉分析结果并结合有机碳δ13 C及高精度14 C测年等资料 ,阐明沙漠 /黄土过渡区 1 3kaBP以来古植被记录的季风气候事件。古植被经历了荒漠草原_干草原_半荒漠_湿润草原_荒漠_疏林草原_荒漠草原_草原_荒漠草原 9个阶段。冰后期的半荒漠_湿润草原_荒漠对应于其中冷干_凉湿_冷干的YoungerDryas事件 ,全新世气候适宜期以及 4.5～ 3.5kaBP的另一气候较适宜期等在研究区均有明显表现

关键词： 沙漠* 黄土过渡带；古植被；季风演化；气候事件

Key words: desert/loess transition zone, palaeovegetation, monsoon evolution, climate events