摘要
As have been determined, the ratios of oxides and the contents of CaCO3 show a tendency to increase from bottom to top in Luochuan loess section, whereas an opposite tendency is observed for the relative values of weathering leaching or accumulation of loess, Moreover, the limits of oxide ratios from less to greater than the average value coincide with the boundary between Wucheng and Lishi loess strata, as well as with the boundary of magnetic polarity reversal. The ratios of oxides and the variations of relative weathering-leaching or accumulation extents are synchronous with the fluctuation of CaCO3 contents. From this investigation, it is shown that the ratios of oxides in the superimposed loees and paleosols from the loess profile are found rhythmically varied. These Characteristics might be explained by the hypothesis of repeated climatic fluctuation from dry (loess) to humid (paleosol) during the Quaternary period.
As have been determined, the ratios of oxides and the contents of CaCO3 show a tendency to increase from bottom to top in Luochuan loess section, whereas an op-posite tendency is observed for the relative values of weathering leaching or accumulation of loess. Moreover, the limits of oxide ratios from less to greater than the average value coincide with the boundary between Wucheng and Lishi loess strata, as well as with the boundary of magnetic polarity reversal. The ratios of oxides and the variations of relative weathering-leaching or accumulation extents are synchronous with the fluctua-tion of CaC03 contents.From this investigation, it is shown that the ratios of oxides in the superimposed loess and paleosols from the loess profile are found rhythmically varied. These chara-cteristics might be explained by the hypothesis of repeated climatic fluctuation from dry (loess) to humid (paleosol) during the Quaternary period.
出处
《地球化学》
CAS
1981年第4期381-387,共7页
Geochimica
