青藏高原北部可可西里地区近4000年来尘暴事件初探——来自库赛湖沉积物粒度的证据  

Dust-storm Events in Kekexili Area,Northern Tibetan Plateau During the Past 4000 Years:Evidence from Grain-size Analysis of Lacustrine Sediments in Kusai Lake

作　　者：王永波[1] 刘兴起[1] 张恩楼[1] 羊向东[1] 姚波[1,2] 

机构地区：[1]中国科学院南京地理与湖泊研究所湖泊与环境国家重点实验室,南京210008 [2]中国科学院研究生院,北京100039

出　　处：《沉积学报》2009年第4期691-696,共6页Acta Sedimentologica Sinica

基　　金：国家重点基础研究发展规划项目(973计划)子课题(批准号:2005CB422002)资助

摘　　要：通过分析库赛湖近4000年来湖相沉积物粒度组成特征,对比人工俘获风成物粒度特征,表明库赛湖沉积物中粗颗粒组分(>64μm)主要由风力搬运作用进入湖泊沉积,记录了该地区尘暴事件历史。重建的尘暴事件序列表明:2500～800cal aBP时段为该地区近4000年来尘暴事件高频发生的阶段,4000～2500cal aBP和800cal aBP以来的时段尘暴事件发生频率较低;近千年来的尘暴事件主要发生于小冰期内的3次降温时段。与贵州董歌洞石笋氧同位素对比分析表明,库赛湖地区近4000年来气候变化受亚洲季风的影响,尘暴事件多发生于夏季风较弱的气候干冷时段。Based on the analyses of grain-size characteristics for lacustrine sediments in Kusai lake, compared with grain-size characteristics of trapped aeolian dust, the results indicate that the coarse grain component（ 〉64 μm） are carried by wind action, recording the dust-storm history of this area. The reconstructed dust-storm sequence show： 2 500 - 800 cal aBP was the period with the highest frequency for dust-storm events, while during 4 000 - 2 500 cal aBP and 800 -0 cal aBP the frequency were lower correspondingly; and the dust-storm events in the past 1 000 years were concentrated in the three cooling events stages of LIA. Comparative analysis with oxygen isotope records from Dongge Cave reveals that the climatic evolution of Kusai Lake area can be effected by the Asian Monsoon during the past 4 000 years, and the dust-storm events occurred frequently during the cold-dry climate due to the decreased Summer Asian Monsoon.

关 键 词：库赛湖 粒度特征 尘暴事件 亚洲季风 青藏高原北部 

分 类 号：P512.2[天文地球—地质学]