Science in China Series D: Earth Sciences

, Volume 44, Supplement 1, pp 261–266 | Cite as

Geochemical indicator of original eolian grain size and implications on winter monsoon evolution



Grain size of eolian deposits from the Loess Plateau in China has been widely used to reconstruct the history of the East Asian winter monsoon. However, the grain size of bulk samples is only partially indicative to the strength of the winter monsoon because post-depositional weathering processes have significantly changed the grain size of original eolian particles. Here, non-weathered loess samples were separated into eight different particle fractions, and major chemical elements were determined in order to establish a geochemical indicator of original eolian grain size. The results show that SiO2 and Al2O3 contents and the SiO2/Al2O3 ratio in different fractions vary regularly with grain size, and that a good linear relation exists between the SiO2/Al2O3 ratio and grain size for the fractions <50 μm. Because Al and Si are among the most stable elements and pedogenic processes in the Loess Plateau cannot affect the SiO2/Al2O3 ratio, this index can be used to reflect the grain size of original eolian particles. Application of this index in the Weinan and Luochuan loess sections of the last climatic cycle shows that SiO2/Al2O3 is in good agreement with median grain size (Md) in the loess units. On the contrary, SiO2/Al2O3 has documented a series of fluctuations in the soil units that are not clearly indicated by the grain-size changes of bulk samples.


SiO2/Al2O3 ratio grain size loess-paleosol sequence winter monsoon 


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. 1.
    Rea, D. K., Snoeckx, H., Joseph, L. H., Late Cenozoic eolian deposition in the North Pacific: Asian drying, Tibetan uplift, and cooling of the Northern Hemisphere, Paleoceanography, 1999, 13(3): 215–224.CrossRefGoogle Scholar
  2. 2.
    Hovan, S. A., Rea, D. K., Pisias, N. G., Late Pleistocene continental climate and Oceanic variability recorded in Northwest Pacific sediments. Paleoceanography, 1991, 6(3): 349–370.CrossRefGoogle Scholar
  3. 3.
    Liu, T. S., Loess and Environment (in Chinese), Beijing: China Ocean Press, 1985, 1–251.Google Scholar
  4. 4.
    An, Z. S., Kukla, G., Porter, S. C., et al., Late Quaternary dust flow on the Chinese Loess Plateau, Catena, 1991, 18: 125–132.CrossRefGoogle Scholar
  5. 5.
    Ding, Z. L., Liu, T. S., Rutter, N. W., et al., Ice-volume forcing of East Asian winter monsson variations in the past 800,000 years, Quaternary Research, 1995, 44: 149–159.CrossRefGoogle Scholar
  6. 6.
    Lu, H. Y., An, Z. S., Paleoclimatic significance of grain size of loess-paleosol deposit in Chinese Loess Plateau, Science in China, Ser. D, 1998, 41(6): 626–631.CrossRefGoogle Scholar
  7. 7.
    Guo, Z. T., Peng, S. Z., Hao, Q. Z., et al., Late Tertiary development of aridification in Northwestern China: Link with the arctic ice-sheet formation and Tibetan uplifts, Quaternary Sciences (in Chinese), 1999, (6): 556–567.Google Scholar
  8. 8.
    Chen, F. H., Feng, Z. D., Zhang, J. W., Loess particle size date indicative of stable winter monsoons during the last interglacial in the western part of the Chinese Loess Plateau, Catena, 2000, 39: 233–244.CrossRefGoogle Scholar
  9. 9.
    Xiao, J. L., Porter, S. C., An, Z. S., et al., Grain size of quartz as a indicator winter monsoon strength on the Loess Plateau of central China during the last 130,000 yr. Quaternary Research, 1995, 43: 22–29.CrossRefGoogle Scholar
  10. 10.
    Gallet, S., Jahn, B. M., Lanoe, B. V. L. et al., Loess geochemistry and implications for particle origin and composition of the upper continental crust, Earth and Planetary Science Letters, 1998, 156: 157–172.CrossRefGoogle Scholar
  11. 11.
    Wen, Q. Z., Geochemistry of the Chinese Loess (in Chinese), Beijing: Science Press, 1989, 36–63.Google Scholar
  12. 12.
    Liu, T. S., Composition and Texture of Loess (in Chinese), Beijing: Science Press, 1966, 46–56.Google Scholar
  13. 13.
    Liu, T. S., Guo, Z. T., Liu, J. Q., et al., Variation of Eastern Asian monsoon over the last 140,000 years. Bulletin de la Société Geologique de France, 1995, 166: 221–229.Google Scholar
  14. 14.
    Guo, Z. T., Liu, T. S., Fedoroff, N., et al., Climate extrenes in loess of China coupled with the strength of deep-water formation in the North Atlantic, Global and Planetary Changes, 1998, 18: 113–128.CrossRefGoogle Scholar
  15. 15.
    Chen, J., Ji, J. F., Qiu, G., et al., Geochemical studies on the intensity of the chemical weathering in Luochuan loess-paleosol sequence, China, Science in China, Ser. D., 1998, 41(3): 235–241.CrossRefGoogle Scholar
  16. 16.
    Gu, Z. Y., Lal, D., Liu, T. S. et al., Weathering histories of Chinese loess deposits based on uranium and thorium series nuclides and cosmogenic10Be, Geochemica et Cosmochimica Acta, 1997, 61: 5221–5231.CrossRefGoogle Scholar
  17. 17.
    Xiao, J. L., Zheng, H. B., Zhao, H., et al., Variation of winter monsoon intensity on the Chinese Loess Plateau, central China during the last 130,000 years: Evidence from grain size distribution, Quaternary Research, 1992, 31: 13–19.CrossRefGoogle Scholar
  18. 18.
    Guo, Z. T., Liu, T. S., An, Z. S., Paleosols of the last 0.15 Ma in the Weinan loess section and their paleoenvironments. Quaternary Sciences (in Chinese) 1994, (3): 256–269.Google Scholar
  19. 19.
    An, Z. S., Kukla, G. J., Porter, S. C., et al., Magnetic susceptibility evidence of monsoon variation on the Loess Plateau of central China during the last 130,000 years, Quaternary Research, 1991, 36: 29–36.CrossRefGoogle Scholar
  20. 20.
    Ding, Z. L., Yang, S. L., Sun, J. M. et al., Re-organization of atmospheric circulation at about 2.6 Ma over Northern China, Quaternary Sciences (in Chinese), 1999, (3): 277–281.Google Scholar

Copyright information

© Science in China Press 2001

Authors and Affiliations

  1. 1.Institute of Geology and GeophysicsChinese Academy of SciencesBeijingChina
  2. 2.Tai’an Teacher’s CollegeTai’anChina

Personalised recommendations