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毛乌素沙漠东南缘萨拉乌苏河流域米浪沟湾剖面MGS1层段含有11个由古沙丘砂与河湖相或古土壤构成的沉积旋回。通过对该层段粒度和CaCO3的分析,发现其河湖沼相和古土壤的平均粒径、分选系数、偏度和峰态的值明显高于古沙丘砂;CaCO3含量在古沙丘砂及其上覆的河湖相和古土壤中依次变化于0.07%～0.32%(平均值为0.16%)、0.05%～1.50%(0.27%)和0.06%～1.42%(0.64%),并与平均粒径呈显著相关(相关系数0.8);构成与沉积旋回波动韵律相同的11个峰谷交替的粒度和CaCO3旋回,指示了全新世气候冷、暖的变化过程和东亚冬夏季风千年尺度交替变化的气候旋回。这些旋回中的冬季风主导时期可与北大西洋8 200、5 000、4 000、2 700、1 400aBP等寒冷事件进行对比,和中国若干地点的气候波动具有良好对应关系,可能表明全新世东亚季风在全球大气、海洋、陆地和全球冰量变化的共同作用下,表现为干冷冬季风和暖湿夏季风的相互交替的千年尺度的气候变化特征。
The MGS1 layer of the Mi Langgouwan section in the Sara Wusu River Basin, southeastern margin of the Mu Us Desert, contains 11 sedimentary cycles formed by ancient sand dunes and river lacustrine or paleosol. Through the analysis of grain size and CaCO3 in this interval, the average grain size, sorting coefficient, skewness and kurtosis of the lacustrine facies and the paleosol were found to be significantly higher than those of the ancient sand dunes; 0.07% -0.32% (average 0.16%), 0.05% -1.50% (0.27%) and 0.06% -1.42% (0.64%) in the overlying river and lake and paleosol, (Correlation coefficient of 0.8). The eleven peaks and valleys and the CaCO3 cycles that constitute the same rhythm of sedimentary cycle fluctuations indicate the climate of Holocene climatic and warming changes and the East Asian winter monsoon millennial scale alternation climate Swing. The dominant winter monsoon periods in these cycles can be compared with those of the North Atlantic such as 8 200, 5 000, 4 000, 2 700 and 1 400 aBP climatic events and have good correspondence with climate fluctuations in several places in China, possibly indicating that the Holocene East Asian monsoon Under the influence of global changes in the atmosphere, oceans, terrestrial and global ice volume, the climate change characteristics of the millennium-scale alternating dry-cold winter monsoon and warm-humid summer monsoon are shown.