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Zr/Rb比值因不受后期成壤作用影响,在黄土高原黄土堆积中可作为较好的冬季风气候替代性指标。与黄土沉积相比,中国北方沙地的气候变化研究相对较弱,能够敏感反映沙地气候变化的替代性指标仍处于探索阶段。本文选取东亚季风控制区的毛乌素沙地、浑善达克沙地和科尔沁沙地11个典型的风成沉积序列,对Zr/Rb比值及其意义进行了研究。通过全岩样品Zr、Rb元素含量、Zr/Rb比值与平均粒径和>63μm的粗颗粒百分含量对比分析,发现在毛乌素沙地,Zr/Rb比值与粗颗粒百分含量和平均粒径成正相关关系,与黄土高原的变化趋势相似,可作为冬季风强度的替代性指标。而在浑善达克沙地和科尔沁沙地,虽然Rb含量在砂质古土壤层中随着细颗粒物质的增加而增大,与毛乌素沙地的变化相同;但是,Zr含量也表现出增加趋势,导致Zr/Rb比值变化趋势与毛乌素沙地相反。其主要原因可能是沙地所处的构造地貌单元不同,物源区存在差异。因此,Zr/Rb比值作为冬季风的替代性指标在不同沙地应用需要慎重分析。
The ratio of Zr / Rb can be used as an alternative proxy for the winter monsoon climate in the loess accumulation in the Loess Plateau because it is not affected by late soil formation. Compared with loess sediments, the research on climate change in the sandy land of northern China is relatively weak, and alternative indicators that can sensitively reflect the climate change in the sandy land are still under exploration. In this paper, eleven typical aeolian sedimentary sequences from the Mu Us Sandland, Hunshandake Sandy and Horqin Sandy Lands in the East Asian monsoon controlled area are selected to study the Zr / Rb ratio and its significance. By comparing the Zr, Rb and Zr / Rb ratio with the average particle size and the percentage of coarse particles> 63μm in the whole rock samples, it was found that the ratio of Zr / Rb to the percentage of coarse particles and the average particle size Which is similar to that of the Loess Plateau and can be used as an alternative indicator of winter monsoon intensity. However, in Hunshandake and Horqin sandy areas, although the Rb content increased with the increase of fine-grained matter in the sandy paleosol layer, the same with the Mu Us sandy land; however, the Zr content also showed an increase Trend, resulting in the trend of Zr / Rb ratio changes with the Mu Us sand opposite. The main reason for this may be that the tectonic units in the sand are different and the provenance areas are different. Therefore, the Zr / Rb ratio needs to be carefully analyzed in different sandy areas as an alternative indicator of winter monsoon.