【摘要】 黄旗海湖泊柱状沉积物的全样、77～20μm、<20μm粒级的钛(Ti)、锰(Mn)、锶(Sr)、銣(Rb)、钡(Ba)、锆(Zr)等元素含量分析表明,元素在湖泊沉积物各粒级组分的丰度存在较大差异:Ti、Zr倾向于在粗颗粒中富集,Mn、Sr、Rb倾向于在细颗粒中富集,Ba的富集粒级不明显。Ti、Zr与Mn、Rb的颗粒粒级富集倾向可能是其硅酸盐矿物颗粒碎化过程的结果,而Sr则与湖泊自生碳酸盐有关。元素比值Zrc/(Rbc+Bac)、Zrc/Rbc与Ti、Zr的粒度效应Tic/Tif、Zrc/Zrf指示了沉积物重、轻矿物的相对比率,是流域侵蚀强度与湖泊涨缩的信息指示;Ba、Rb与Sr在细粒级的含量之比Baf/Srf、Rbf/Srf指示了硅酸盐与碳酸盐矿物的相对含量,是流域风化、侵蚀搬运强度与湖泊过程(包括物理/化学/生物)等混合信息指示,没有明确的环境指向性。更多还原

【Abstract】 The terminal Huangqihai Lake is located at the northern margin of the modern East Asian summer monsoon,and its evolution is sensitive to climate changes.Profile H3 is a few kilometers away to the southeast of the lake which was consisted of fine sand and silt deposited during ca 8.5~2.0 ka BP.During this period,Huangqihai Lake experienced its highest lake level in Holocene as well as largest summer monsoon precipitation.Analysis of Rb,Sr,Ba,Mn,Ti,Zr elements in entire sample,the fraction of grain size of 20~77 μm and <20 μm,and Carbonate Minerals content in <20 μm fraction indicated that element abundance in different grain size exhibited different features.Ti and Zr has enrichment tendency in the fraction of grain size of 20~77 μm;Mn,Sr and Rb was apt to enrich in the fraction of grain size of <20 μm,and the enrichment of Ba was not distinct.The enrichment of Ti,Zr,Mn and Rb probably were the fragmentating characteristics of their silicate minerals,and that of Sr was caused by lacstrine autogenic carbonate.Zrc/(Rbc+Bac)ratio,Zrc/Rbc ratio,and the grain size effect of Zr and Ti(or Tic/Tif,Zrc/Zrf) showed the relative content of heavy and light minerals,which indicated the intensity of erosion in basin and transportation from basin to lake,and lake enlarging and reducing information.The information which indicated by Baf/Srf ratio,Rbf/Srf ratio in <20 μm fraction was complicated and has no directly environmental implication.更多还原