中文摘要：

孢粉浓缩物作为孢粉学研究的基础和前提，其纯度直接影响到孢粉学研究结论的准确性。干旱区湖泊沉积物孢粉浓缩物中残留的不溶矿物颗粒，对孢粉鉴定、分析和测年等造成干扰。明确不溶颗粒的矿物成分，探讨孢粉提取过程中化学反应作用机制，对完善干旱区湖泊沉积物孢粉浓缩物提取方法有重要意义。本文选取石羊河下游终端湖-猪野泽地区沙坑井（SKJ）和九驼梁（JTL）剖面湖泊沉积物及相应层位孢粉浓缩物，进行矿物成分对比研究，结果显示：全样和孢粉浓缩物的矿物成分均以石英和硅酸盐类矿物为主；孢粉浓缩物中矿物组成更为多样，硅酸盐矿物种类与全样差异较大，这可能由于石英与硅酸盐类矿物和氢氟酸反应，在溶液中产生了大量硅酸根、含氟金属络合阳离子和金属阳离子所导致。两种阳离子通过与硅酸根结合，或与原有硅酸盐矿物发生置换反应，使孢粉浓缩物中出现了全样中不存在的硅酸盐或碳酸盐矿物。孢粉浓缩物中较多的矿物种类也可能与样品总量减少有关，因为微量矿物的含量会因其他矿物的大量减少而增加，从而在浓缩物中得以表现。此外，全样矿物与氢氟酸反应后会生成硅凝胶物质，有可能会阻碍酸与样品的进一步反应，使孢粉浓缩物中存在未能完全反应的石英和少量碳酸盐类矿物。因此，干旱区湖泊沉积物孢粉提取过程中，应当慎用氢氟酸，在充分分散样品后，选择适当比重的重液浮选去除大部分石英和硅酸盐类，再使用氢氟酸多次处理，是完善干旱区湖泊沉积物孢粉浓缩物提取方法的有效途径。

英文摘要：

As the basis and premise of palynology research, the purity of pollen concentrates is directly related to the accuracy of palynology research. Insoluble mineral particles in pollen concentrates of lake sediments have caused disturbance in pollen identification, analysis, and dating. To explore mineral composition of insoluble particles and the chemical reaction mechanism in pollen extraction has an important significance on perfection of the pollen extraction method of lake sediments in arid areas. In the eastern Qilian Mountains, the Shiyang River drainage area is roughly at geographical coordinates of 37°02＇- 39°17＇N, 100°57＇- 104°57＇E. Zhuye Lake, the terminal lake of the drainage area, is a tectonic rift basin, belonging to the Qilian Mountains piedmont fault basin. The Quaternary unconsolidated lacustrine and alluvial can reach up to 300meters thick in the basin. In this paper, we chose ten sets of sediment samples from the Shakenjing section （SKJ, 39°00＇N, 103°52＇E; altitude： 1305m; depth： 3.55m） （S1-S10） and 6 from the Jiutuoliang section （JTL, 39° 09＇N,104° 08＇E; altitude： 1308m; depth： 3.00m） （J1- J6）, to conduct a comparative study on the mineral composition. The results revealed that the mineral compositions of lake sediments and pollen concentrates are mainly quartz and silicate minerals. In pollen concentrates samples, mineral composition is more diverse, while silicate mineral types are different from lake sediments. Under the action of hydrofluoric acid, quartz and silicate minerals can produce a large number of silicates, fluoride metal complexing cations and metal cations. These two kinds of cations can combine with silicates, or develop substitution reactions with original silicate minerals. So there are many new kinds of silicate and carbonate minerals in pollen concentrates samples, compared with lake sediments samples. Furthermore, as a result of compensation of diminishing, trace minerals could occur in pollen concentrates samples. Meanwhile, s