新疆托勒库勒湖孢粉记录的4．2kaBP气候事件  

AN ABRUPT CLIMATIC EVENT AROUND 4.2 CAL KA BP DOCUMENTED BY FOSSIL POLLEN OF TUOLEKULE LAKE IN THE EASTERN XINJIANG UYGHUR AUTONOMOUS REGION

作　　者：陶士臣[1,2] 安成邦[1] 陈发虎[1] Kam-biu Liu 唐领余[4] 

机构地区：[1]兰州大学西部环境教育部重点实验室,兰州730000 [2]中国科学院边缘海地质重点实验室,中国科学院南海海洋研究所,广州510301 [3]Department of Oceanography and Coastal Sciences,Louisiana State University,Baton Rouge,LA 70803,USA [4]中国科学院南京地质古生物研究所,南京210008

出　　处：《古生物学报》2013年第2期234-242,共9页Acta Palaeontologica Sinica

基　　金：全球变化研究国家重大科学研究计划项目(批准号:2013CB956102);国家自然科学基金项目(批准号:41130102;41272199);中国科学院南海海洋研究所青年人才领域前沿项目(批准号:SQ201209)共同资助

摘　　要：发生在大约4200年前的一场持续干旱可能是当时史前文明快速衰落的重要推手,这在全球许多区域均有记录,但在中国西北干旱区是否存在该事件依然缺乏有力证据。本文通过分析托勒库勒湖沉积地层的孢粉,发现新疆地区也存在类似4.2 ka BP气候事件的记录。4.5—3.8 cal ka BP期间的孢粉谱与前后时段相比有显著差异,禾本科和蒿属花粉含量快速降低、藜科急剧增加、A/C值降低;区域环境短期内变得极为寒冷-干旱,先前的草原/荒漠草原演化为荒漠。对比也发现,尽管这一事件在不同研究点的开始和结束时间略有差异,但变化特征具有较好的一致性。目前,关于这次事件的驱动机制仍不清楚,还需在新疆及其他敏感区域开展更多古气候研究。A prolonged cold and dry event that occurred about 4 200 years ago might play a significant role in the collapse of pre-historical cultures around the World. However, evidence of this event is rare in Northwest China. Pollen data of Tuolekule Lakeindicate that this event is also found in Xinjiang region. During 4.5-3.8 cal ka BP, the oscillation of pollen assemblages in Tuolekule Lake shows rapid environmental and climatic changes. Gramineae pollen dramatically decreased, while Chenopodiaceae pollen increased remarkably, and the A/C ratio also reduce. This shift in vegetation components implies that climate rapidly became extremely cold and dry during this period （4. 5-3.8 cal ka BP）. During this episode the steppe/desert-steppe was displaced by desert vegetation. While this 4.2 ka BP event is recorded by many sites around the world, the onset and termination of this event differs from place to place, possibly from alterations in resolution and dating methods. The climatic disruptions during the 4. 2 ka BP event are variable due to different geographic settings and resolution. Unfortunately,the mechanism of this event is still unclear and more paleoclimatic records are needed to address it in detail.

关 键 词：孢粉 4 2 KA BP气候事件 全新世 托勒库勒湖 新疆 

分 类 号：P532[天文地球—古生物学与地层学]