Science in China Series D: Earth Sciences

, Volume 51, Issue 3, pp 321–330

Molecular fossil and paleovegetation records of paleosol S4 and adjacent loess layers in the Luochuan loess section, NW China

  • Zhang HuCai 
  • Yang MingSheng 
  • Zhang WenXiang 
  • Lei GuoLiang 
  • Chang FengQin 
  • Pu Yang 
  • Fan HongFang 
Article

DOI: 10.1007/s11430-008-0012-9

Cite this article as:
Zhang, H., Yang, M., Zhang, W. et al. Sci. China Ser. D-Earth Sci. (2008) 51: 321. doi:10.1007/s11430-008-0012-9

Abstract

Using gas chromatography-mass spectrometry (GC-MS) technique, a series of biomarkers were identified, including n-alkanes, n-alkane-2-ones, isoprenoid etc. from the loess-paleosol samples collected from the S4 and adjacent L5, L4 of the Luochuan loess section, Northwestern China. Based on these data, especially n-alkanes and high-resolution magnetic susceptibility and grain size data, the paleoenvironment and paleovegetation history during S4 was reconstructed. The CPI (Carbon Predominance Index) and correlation between n-alkanes and magnetic susceptibility and grain size data demonstrated that the molecular fossils in paleosol and loess layers can reflect the vegetation condition during the loess-paleosol formation, if the allochthonous organic inputs could be excluded reasonably. The ACL (average chain length) index is correlated well with paleomagnetic susceptibility and grain size variations, displaying their good synchrony with warm and humid climate. However, it relatively lagged behind the paleomagnetic susceptibility and the grain size variations when the climate began to deteriorate. During the formation period of paleosol, the n-alkanes was dominated by C31 homologue, indicating that the primary organic input originated from herbs. Our study also demonstrated that the herbs were more flourish than wood plants in Loess Plateau, especially in the Luochuan area during the warm and humid phase, and there was no typical forest vegetation developed in the studied period.

Keywords

paleoenvironment Paleosol S4Luochuan loess sectionbiomarkerpaleovegetation

Copyright information

© Science in China Press 2008

Authors and Affiliations

  • Zhang HuCai 
    • 1
    • 2
  • Yang MingSheng 
    • 1
  • Zhang WenXiang 
    • 1
  • Lei GuoLiang 
    • 1
  • Chang FengQin 
    • 1
  • Pu Yang 
    • 2
  • Fan HongFang 
    • 1
  1. 1.Key Laboratory of Western China’s Environmental Systems, Ministry of Education, College of Earth and Environment SciencesLanzhou UniversityLanzhouChina
  2. 2.State Key Laboratory of Lake and Environment Sciences, Nanjing Institute of Geography and LimnologyChinese Academy of SciencesNanjingChina