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中国沙漠 ›› 2011, Vol. 31 ›› Issue (6): 1398-1405.

• 古气候与环境演变 • 上一篇    下一篇

近6 ka以来科尔沁沙地东部气候变化记录

刘 冰, 靳鹤龄, 孙 忠   

  1. 中国科学院寒区旱区环境与工程研究所, 甘肃 兰州 730000
  • 收稿日期:2010-12-14 修回日期:2011-05-03 出版日期:2011-11-20 发布日期:2011-11-20

Climate Change in East Horqin Sandy Land Since 6.0 ka BP

LIU Bing, JIN He-ling, SUN Zhong   

  1. Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China
  • Received:2010-12-14 Revised:2011-05-03 Online:2011-11-20 Published:2011-11-20

摘要: 根据科尔沁沙地东部TL剖面磁化率、有机质、化学元素等气候代用指标的变化特征和14C测年结果,分析和讨论了科尔沁沙地6 ka BP以来的气候变化过程。实验数据显示,高频磁化率、低频磁化率、有机质、Al2O3含量变化趋势基本一致,且峰值段对应古土壤层,谷值段对应风成砂层。依据气候代用指标的变化将6 ka BP以来科尔沁沙地气候变化分为3个阶段:Ⅰ.6.0~4.2 ka BP,气候暖湿,夏季风逐渐增强,并占主导,冬季风较弱,与全新世大暖期对应,但存在百年尺度的气候波动,其中:6.0~5.6 ka BP,5.6~5.4 ka BP,4.9~4.2 ka BP气候暖湿;5.6~5.5 ka BP,5.4~4.9 ka BP气候相对冷干。Ⅱ.4.2~1.3 ka BP,气候相对暖湿,与上一阶段相比夏季风有所减弱,但仍强于冬季风,其间也存在次一级波动,3.7~3.6 ka BP,3.4~1.3 ka BP,气候相对暖湿,4.2~3.7 ka BP,3.6~3.4 ka BP气候相对干冷。Ⅲ.1.3~0.65 ka BP以来,气候波动频繁,后期有向暖湿发展的趋势。总体而言,区域气候变化与全球具有较好的一致性。

关键词: 科尔沁沙地, 磁化率, 有机质, 化学元素, 气候变化

Abstract: Climate change process in eastern Horqin Sandy Land since 6.0 ka BP was analyzed based on data of magnetic susceptibility, organic matter, chemical elements and 14C dating. Results showed there were similar variation tendencies for the above indexes, and the peak phases corresponded to the paleosol layer while the valley phases reflected the sandy layer. According to variations of the indices, the climate change process in eastern Horqin Sandy Land can be divided into three stages: (Ⅰ) 6.0—4.2 ka BP, corresponding to the Holocene Climatic Optimu. The intensifying summer monsoon dominated this period and winter monsoon was weak; the climate was generally warm and humid except for fluctuations on centennial scale. During this period, the warm and humid climate dominated in 6.0—5.6 ka BP, 5.6—5.4 ka BP, 4.9—4.2 ka BP, and the relatively cold and arid climate existed in 5.6—5.5 ka BP, 5.4—4.9 ka BP. (Ⅱ) 4.2—1.3 ka BP, the summer monsoon showed a relatively weaker tendency compared to the former phase but was still more powerful than the winter monsoon; the climate was relatively warm and humid, and there was also small scale fluctuations. During this period, the warm and humid climate dominated in 3.7—3.6 ka BP, 3.4—1.3 ka BP, and the relatively cold and arid climate existed in 4.2—3.7 ka BP, and 3.6—3.4 ka BP. (Ⅲ) 1.3—0.65 ka BP, the climate fluctuated frequently, and there was a tendency to warm and humid in the later stage. As a whole, the regional climate change is consistent with the global climate change.

Key words: Horqin Sandy Land, magnetic susceptibility, organic matter, chemical elements, climate change

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