Duststorm Events in Kekexili Area, Northern Tibetan Plateau During the Past 4000 Years: 〖WTBZ〗Evidence from Grainsize Analysis of Lacustrine Sediments in Kusai Lake
-
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(>64 μm)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:2 500~800 cal aBP时段为该地区近4 000年来尘暴事件高频发生的阶段,4 000~2 500 cal aBP和800 cal 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4 000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。Abstract: Based on the analyses of grainsize characteristics for lacustrine sediments in Kusai lake, compared with grainsize characteristics of trapped aeolian dust, the results indicate that the coarse grain component(>64 μm) are carried by wind action, recording the duststorm history of this area. The reconstructed duststorm sequence show: 2 500~800 cal aBP was the period with the highest frequency for duststorm events, while during 4 000~2 500 cal aBP and 800~0 cal aBP the frequency were lower correspondingly; and the duststorm 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 duststorm events occurred frequently during the colddry climate due to the decreased Summer Asian Monsoon.
-
Key words:
- Kusai Lake /
- grainsize characteristics /
- duststorm events /
- Asian Monsoon /
- Northern Tibetan Plateau
-

计量
- 文章访问数: 2155
- HTML全文浏览量: 14
- PDF下载量: 739
- 被引次数: 0