新疆伊犁黄土元素地球化学特征及古环境意义  

Geochemical Characteristics and Paleoen-Vironmental Significance of the Loess in the Ili Region,Xinjiang

作　　者：李传想[1,2] 宋友桂[1] 王乐民 

机构地区：[1]中国科学院地球环境研究所黄土与第四纪地质国家重点实验室,陕西西安710075 [2]中国科学院研究生院,北京100049 [3]新疆维吾尔自治区地质勘查基金项目管理中心,新疆乌鲁木齐830002

出　　处：《新疆地质》2012年第1期103-108,共6页Xinjiang Geology

基　　金：国家自然科学基金(41172166;40972230);国家重点基础研究规划项目(2010CB833406)联合资助

摘　　要：通过对新疆伊犁波马剖面黄土-古土壤序列常量、微量元素及相关参数分析研究,讨论末次冰期以来伊犁黄土常量元素分异规律及古环境意义.结果表明,伊犁波马剖面S1以来黄土-古土壤序列各层常量元素含量均呈现出SiO2>Al2O3>CaO>Fe2O3>MgO>K2O>Na2O变化特征,剖面序列中常量元素含量及相关参数变化,与黄土、古土壤层相互交替叠置不具对应性,明显有别于黄土高原.末次冰期以来黄土和古土壤形成时干冷程度强于黄土高原黄土,更高于古土壤,淋溶差异程度不及黄土高原.S1以来伊犁黄土物质来源基本相同,古土壤形成时环境条件不相同,以干冷或湿冷为特征,即使同一古土壤地层单元不同层位其水热组合条件也存在差异,波马剖面黄土-古土壤元素地球化学记录末次冰期以来沉积气候环境总体相对干旱.Based on the analytical results of the oxides,trace elements and its related parameters in Boma section in the Ili Basin, the paper discusses the geochemical differentiation of key elements and the environmental significance of its related parameters in Ili loess since the last glaciation. The results show that the oxides at the Boma section possess the similar characteristic： the content o.f SiO2〉A1203〉CaO〉Fe203〉MgO〉K20〉Na20,the changes in the major elements content and related parameters in the Ili loess have no correspondence with the alternative of loess-paleosol sequence, which differs from the loess on the Loess Plateau;the dry-cold degree during the loess and paleosol formation in Ili Region since the last glaciation was stronger than that of the loess on the Loess Plateau,far stronger than that of paleosol, the differentiation of both is no obvious, moreover, the chemical weathering leaching degree of the two is weaker than that of the loess on the Loess Plateau, far weaker than that of paleosol, the differentiation in the chemical weathering leaching degree is far from that of the Loess Plateau.Meanwhile, the material sources in the Ili loess since the S1 has no change; the environmental conditions during the paleosol formation are different, sometimes the feature in dry and cold, sometimes in cold and wet, even if the different stratigraphic units in the same paleosol layer have different hydro-thermal combination, the sedimentary environment recorded by the Boma loess-paleosol section in the Ili region is relatively drought since the last glaciation; the hydro-thermal combination （precipitation, temperature and evaporation, etc.） may play an important role on chemical weathering process.

关 键 词：伊犁盆地 末次冰期以来 黄土和古土壤 地球化学特征 古环境 

分 类 号：P595[天文地球—地球化学]