摘要
巴丹吉林沙漠查格勒布剖面150kaBP以来存在25个由风成沙丘砂与黄土、古土壤、湖相和冲坡积砂土砾石层构成的沉积旋回。剖面常量化学元素分析显示:湖相、黄土和古土壤中的Al2O3、Fe2O3+FeO、CaO、MgO、K2O、Na2O和TiO含量基本上高于风成沙丘砂,而SiO2则呈相反变化,构成了与沉积旋回相应的150kaBP以来25个元素变化旋回。剖面中各元素的这种分布和集散规律也与元素的富集系数和淋失系数波动一致。研究表明,暖湿气候作用下稳定性元素Al2O3、TOFe、TiO和非稳定性元素CaO、MgO、Na2O、K2O都能相对富集,与剖面所处的特殊的洼地地貌位置有关。常量化学元素的综合分析表明,这种元素变化旋回是由巴丹吉林沙漠晚更新世以来的干寒多风与温湿至暖湿气候变化所致,其根本原因与冰期、间冰期气候波动影响下东亚冬夏季风的"拉锯式"摆动有关。
There are 25 sedimentary cycles that are made up of aeolian palaeo-dune sands,loess,palaeosol,lacustrine facies and alluvial-hillslope sandy soils and gravels in Chagelebu section. The analysis of the main chemical elements in the section shows that the contents of Al_(2)O_(3, )Fe_(2)O_(3)+FeO, CaO, MgO, K_(2)O, Na_(2)O and TiO in the lacustrine facies, loess and palaeosol are higher than those in the aeolian palaeo-dune sands, but the contents of the SiO_(2) take on converse change. It constitutes 25 element-change cycles corresponding with above-mentioned sedimentary cycles since 150 ka BP. The regulation of distribution, gathering and migration of each element in the section are corresponding with the fluctuations of its gathering coefficient and leach coefficient. The study shows that stable elements Al_(2)O_(3),Fe_(2)O_(3)+FeO,TiO and unstable elements CaO,MgO,Na_(2)O,K_(2)O can both gather together in the warm and humid climate, and that have to do with its special low-lying depression. The comprehensively analysis of the main chemical elements indicates that the element-change cycles result from the dry-cold, windy and mild-humid to warm-humid climate-change since the late Pleistocene, Badain Jaran Desert. The essential reason bears relationship with the back and force swing of the East Asia winter monsoon and summer monsoon influenced by climatic vicissitudes during glacial and interglacial period.
出处
《中国沙漠》
CSCD
北大核心
2005年第1期8-14,共7页
Journal of Desert Research
基金
国家重点基础研究发展计划资助项目(2004CB720200)
中国科学院知识创新工程重要方向项目(KZCX2 SW 118)共同资助
