陕北靖边三道沟黄土剖面常量元素地球化学特征  

Major Element Geochemical Features of Sandaogou Loess Section in Jingbian County,Northern Shaanxi Province

作　　者：张培新 王攀[1] 杨振京[1] 石迎春[1] 宋超[1] 郭娇[1] 董秋瑶[1] 陈洪云[1] ZHANG Pei-xin;WANG Pan;YANG Zhen-jing;SHI Ying-chun;SONG Chao;GUO Jiao;DONG Qiu-yao;CHEN Hong-yun(Institute of Hydrogeology and Environmental Geology,Chinese Academy of Geological Sciences,Shijiazhuang 050061,China;Institute of Ecological Resources and Landscape,College of Earth Sciences,Chengdu University of Technology,Chengdu 610059,China)

机构地区：[1]中国地质科学院水文地质环境地质研究所,石家庄050061 [2]成都理工大学生态资源与景观研究所,地球科学学院,成都610059

出　　处：《科学技术与工程》2019年第28期56-63,共8页Science Technology and Engineering

基　　金：中国地质科学院水文地质环境地质研究所基本科研业务费(SK201310);中国地质科学院基本科研业务费(YYWF201627)资助;中国地质调查局地质调查工作项目(12120113005900)

摘　　要：靖边三道沟黄土剖面地处毛乌素沙地-黄土高原的交界地带,存在良好的地质环境变化记录。为了探讨靖边地区黄土的来源、成因、风化程度,选取靖边县的三道沟剖面地球化学元素进行分析并与其他剖面对比。其结果表明:(1)三道沟剖面常量元素之和(Si O2、Al2O3、Ca O)以及UCC标准化曲线与其他典型风成剖面及存在很好的对应性,佐证其风成成因;(2)三道沟剖面处在风化初期的去Ca、Na阶段,古土壤中元素迁移特征较黄土层中更明显;(3)根据元素比值的分布及示踪元素的分析,三道沟剖面黄土与武威黄土、洛川黄土、西峰红黏土、下蜀黄土存在相似源区;(4)三道沟黄土剖面与其他地区剖面对比分析,指示风化程度由西北到东南呈现递增趋势,与现代季风气候的空间变化趋势一致,也表明风化程度的差异是东亚季风变化所造成的。Sandaogou loess section is located in the transition zone of the Mu Us Sands and Loess Plateau,which is a good record of geological environment change. In order to discuss the provenance,origin and chemical weathering degree of loess in this region,geochemical elements of Jingbian loess section were analysed and compared with other typical aeolian loess section. The results show as follows.(1)The sum of major elements( including SiO2,Al2 O3,Ca O) and upper continental crust( UCC)-normalized patterns of Sandaogou section are similar to those of typical aeolian loess section,indicating that Sandaogou section is aeolian.(2)Sandaogou section underwent primary weathering stage and it underwent to get rid of Ca and Na. The element migration ratio of paleosol in Sandaogou section is more obvious.(3)The distribution of element ratios and the analysis of trace elements are similar to that of Wuwei loess section,Luochuan loess section,Xifeng red clay section and Xiashu loess section,indicating that these aeolian loess section might have the same source.(4)Comparative analyses of Sandaogou section and other aeolian loess section,indicating that the weathering intensity has a increasing trend form northwest to southeast. The changing trend is well consistent with the modern climate change in China,which is the response to the East Asian monsoon.

关 键 词：三道沟黄土剖面 常量元素 风化程度 不同地区黄土 

分 类 号：P532[天文地球—古生物学与地层学] P595[天文地球—地质学]