作　　者： ; ; ; ; ; ; ; ;

机构地区： 华南师范大学地理科学学院

出　　处： 《地质学报》 2011年第2期300-308,共9页

摘　　要： 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。 This paper attempts to probe the ka-scale climate variation during Holocene by analyzing the contents of trace elements from the MGS1 stratigraphical segment of Milangguowan section in the Salawusu River Valley,southeast of Mu Us Desert.12 out of 14 elements,such as P,Pb,Rb,Nb,Zr,V,Sr,Cu,Ni,As,Ba and Co share similar distribution pattern in the vertical direction of MGS1 except for Cr and Zn.The element contents of the dune sands generally fall in the bottom,and the dune sand of varied sequences,which overlies fluvio-lacustrine and/or paleosols,forms the peak,thus constituting 11 cycles of alternating peak and valley.The fact that the element contents in paleo-mobile dune sands are similar to those of modern dune sands to a great extent shows that the former may be defined as the dominant period of East Asian winter monsoon,and increase of the element contents in the overlying fluvio-lacustrine or paleosols may attribute to dominance of East Asian summer monsoon.11 cycles of elements may represent alternating weather cycle of East Asian winter and summer monsoon during Holocene in the ka-scale.The sediment cycles indicated by the elements reveal the alternation of East Asian winter and summer monsoon during Holocene.In the dominant period of East Asian winter monsoon,the time and the climatic characteristics could correspond to the cold events in North Atlantic and some places of China,which probably indicates the ka-scale environmental variation in the desert of China may be caused by the increase of ice volume in the north hemisphere.

关 键 词： 萨拉乌苏河流域 层段 全新世 微量元素 千年尺度气候变化

领　　域： [天文地球] [天文地球]