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本文以毛乌素沙漠东南缘萨拉乌苏河流域米浪沟湾剖面MGS1层段为代表,试图通过对其的微量元素分析结果探讨该地全新世千年尺度的气候变化。在分析的14种微量元素中,除Cr和Zn以外的12种元素P、Pb、Rb、Nb、Zr、V、Sr、Cu、Ni、As、Ba、Co含量在MGS1剖面的垂直方向上具有这样的分布规律:元素含量值在沙丘砂中差不多都表现为谷,而在不同层位沙丘砂上覆的河湖相或古土壤中则相对为峰,构成11个谷峰交替变化的元素旋回。研究结果表明,MGS1的古流动沙丘砂与萨拉乌苏河流域现代流动沙丘砂在大多数微量元素含量上具有较高程度的一致,可以据此将其确定为东亚冬季风作用的主要时期,而上覆河湖相或古土壤元素含量增高则主要是为盛行的夏季风所致,11个元素旋回代表了全新世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在时间和气候性质上可与北大西洋和我国若干地点寒冷事件进行对比,可能表明这是全新世期间北半球冰量增加引起的我国沙漠区域千年尺度的环境变化。
In this paper, the MGS1 section of the Meilanggouwan section in the Salawusu River basin at the southeastern margin of the Maowusu Desert is represented. The results of the trace element analysis of this area are intended to explore the climatic changes of the Holocene millennial scale. Among the 14 trace elements analyzed, the contents of 12 elements P, Pb, Rb, Nb, Zr, V, Sr, Cu, Ni, As, Ba and Co except for Cr and Zn have a The distribution pattern of elemental contents is almost the same in the dune sand, while in the lacustrine-lacustrine phase or palaeosol in the different layers, the relative abundance of the elements is relatively high, forming eleven alternations of the valleys. The results show that the paleotropical sand dunes of MGS1 and the modern mobile sand dunes of Salawusu River basin are highly consistent with most trace elements and can be identified as the main period of East Asian winter monsoon. Elevated elemental concentrations of the overlying river lacustrine facies or paleosol were mainly caused by the prevailing summer monsoon. The eleven elemental cycles represent the climatic cycle of the Holocene East Asian winter monsoon with millennial scale alternation. The monsoon dominated by these cycles The temporal and climatological comparison with the cold events in the North Atlantic and several locations in our country may indicate that this is a millennium-scale environmental change in the desert region of our country caused by the increase of ice mass in the Northern Hemisphere during the Holocene.