【摘要】 通过提取黄河、辽河和鸭绿江表层沉积物中的碎屑矿物角闪石,对单矿物采用电子探针,对群体角闪石采用ICP-MS和ICP-AES分析其常量元素及微量元素组成。结果表明:角闪石单矿物主成分在一定范围内有较大变化,都具有高Si、Ca、Mg和低Na、K的特征;3条河流的角闪石晶体化学都归属钙角闪石组,半数以上矿物种为镁角闪石;角闪石群体矿物化学显示黄河角闪石的稀土元素浓度明显高于黄土和黄河全岩沉积物,而且重稀土比轻稀土更富集,说明角闪石是黄河和黄土沉积物稀土元素的主要载体之一,角闪石含量变化会对全岩样品稀土元素含量造成重要影响。微量元素特征显示新旧黄河样品间差别很小,与其同一来源物质的事实相符。虽然黄河、辽河和鸭绿江河流样品角闪石主成分相近,但微量元素方面(元素含量、元素含量对比值及特征值)显示较明显不同,样品间多种数值指标相对偏差在20%以上,可作为物源识别的判别标志,如微量元素Ba、Li、Rb、Cs、Ta、Tl、Pb、La、Ce、Pr、Nd等含量的差异,元素对比值c(La)/c(Y)、c(Sr)/c(Rb)、c(Zn)/c(Cu)、c(Gd)/c(Cd)、c(Li)/c(Be)、c(Rb)/c(Cs)、c(Sr)/c(Ba)、c(Hf)/c(Ta)、c(Pb)/c(Bi)等的差异;特征值∑c(REE)、Σc(LREE)、∑c(HREE)、∑c(LREE)/∑c(HREE)、[c(La)/c(Lu)]N、[c(La)/c(Yb)]N、[c(La)/c(Sm)]N等的差异。更多还原

【Abstract】 Detrital amphiboles were separated from surface sediment samples obtained from the mainstream of the Huanghe River,Liaohe River and Yalu River.Chemical composition of individual amphiboles and amphibole population(sum of amphibole grains in a sample)were analyzed by electron microprobe analyzer,and ICP-MS,ICPAES respectively.Results of electron microprobe analyzer show that calcium-amphibole group(more than half are magnesiohornblende)is dominated in the sediments of the three rivers according to their crystallochemical classification.The chemistry composition of individual amphiboles vary in a large extent,and with high Si,Ca,Mg,and low Na,K.Results from amphibole population geochemistry from the Huanghe River reveal significantly higher rare earth element(REE)concentrations than that in loess and whole-rock sediment.Hence,it could be concluded that amphibole is one of the main REE carriers of the Huanghe River sediments and loess deposits.The content changes of amphibole could largely influence the REE content fluctuations in the whole rock.Little difference in trace element content between the new and the abandoned Huanghe River samples possibly indicates the same provenance.Trace elements of amphibole population are significantly different in the three rivers,indicated by more than 20% of relative deviation in terms of some indexes.Some indicators can be used as typomorphic chemical characteristics of amphibole to trace sediments,such as trace elements of Ba,Li,Rb,Cs,Ta,Tl,Pb,La,Ce,Pr,Nd, element ratios of c(La)/c(Y),c(Sr)/c(Rb),c(Zn)/c(Cu),c(Gd)/c(Cd),c(Li)/c(Be),c(Rb)/c(Cs),c(Sr)/ c(Ba),c(Hf)/c(Ta),c(Pb)/c(Bi),and distinguished value of∑c(REE),∑c(LREE),∑c(HREE),∑c(LREE)/ ∑c(HREE),[c(La)/c(Lu)]N,[c(La)/c(Yb)]N,[c(La)/c(Sm)]N.更多还原