论文部分内容阅读
沉积物的化学成分无疑取决于来源物质的成分和沉积后的化学作用。对来自于甘肃灵台7MaBP以来风成沉积序列的红粘土、黄土和古土壤样品的化学分析表明，风成沉积物化学成分的演化主要由沉积前所经历的各种地表作用（尤其是风化作用）所决定，当地成壤作用对化学成分的影响叠加在106a演化趋势上5反映风化程度的化学指标Na／Al值和Fe2+／Fe3+值总体均呈逐步增加的趋势，基本一致于上新世以来全球气候变化的趋势，这可能与青藏高原隆升和北半球冰盖发育加速粉尘物质源区侵蚀同时降低化学风化程度有关。
The chemical composition of the sediment undoubtedly depends on the composition of the source material and the chemical effect after deposition. The chemical analysis of red clay, loess and paleosol samples from the depositional sequence of the Aeolian deposits since 7MaBP in Gansu indicates that the evolution of the chemical composition of the aeolian sediments is mainly caused by various surface processes (especially weathering) It is determined that the influence of local pedogenesis on the chemical composition superimposed on the evolution trend of 106a. The chemical indicators Na / Al and Fe2 + / Fe3 +, which reflect the degree of weathering, all show a gradual increase trend, basically consistent with the global The trend of climate change may be related to the uplift of the Qinghai-Tibet Plateau and the development of ice sheets in the Northern Hemisphere to accelerate the erosion of dust source areas and to reduce the degree of chemical weathering.