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毛乌素沙漠东南缘萨拉乌苏河流域滴哨沟湾剖面DGS1层段主要由沙丘砂、湖沼相和次生黄土组成。根据测年结果,该层段为全新世风沙沉积序列。通过对该层段CaCO_3的分析,发现CaCO_3含量在沙丘砂、湖沼相和次生黄土依次变化于0,35%~2.74%(平均值1.03%)、0.13%~60.31%(平均值22.16%)和8.64%~12.83%(平均值9.21%),并与DGS1层段粒度Mz(平均粒径)呈显著相关(相关系数0.68)。研究表明,毛乌素沙漠冬季风盛行时期沙丘砂堆积,CaCO_3发生迁移;夏季风盛行时期湖沼相发育,CaCO_3相对聚集。据此,我们认为CaCO_3含量变化揭示了毛乌素沙漠在全新世以来经历了多次冬夏季风交互演替的气候变化过程,全新世气候波动主要可分为4个阶段:全新世早期回暖期、全新世鼎盛期、暖冷过渡期和冷干气候不稳定期。
The Dusihe Section of Dalantou Bay section in the Sara Wusu Basin in the southeastern margin of the Mu Us Desert is mainly composed of sand dunes, lacustrine facies and secondary loess. According to the dating results, this interval is the Holocene sandstorm sedimentary sequence. Through the analysis of CaCO_3 in this interval, it was found that CaCO_3 content varied from 0,35% to 2.74% (average value 1.03%) and 0.13% ~ 60.31% (average value 22.16%) in sand dune, lacustrine and secondary loess, And 8.64% ~ 12.83% (average 9.21%), respectively, which were significantly correlated with the grain size Mz (average particle size) of DGS1 (correlation coefficient 0.68). The results show that sand and sand accumulate in the Mu Us Desert during the winter monsoon period, and CaCO 3 migrates. During the prevailing summer monsoon period, lacustrine facies develop and CaCO 3 accumulates relatively. Therefore, we believe that the change of CaCO_3 content reveals the climate change process of the Mu Us Desert experienced many alternations of winter monsoon since the Holocene. The Holocene climatic fluctuation can be divided into four stages: the Early Holocene warm-up period, the Holocene Heyday, warm-cold transition and cold-dry climate instability.