Abstract:

Carbon isotope of loess through S₀ to S₁₁ at luochuan section in Shaanxi Province were experimented.The curve of δ¹³C compares well to the oxygen isotope curves of deep sea sediments from DSDP607 drill.There is obviously negative peak of δ¹³C within S₅ paleosol where the content of δ¹³C is-16.615‰,that shows the climatic optimum,and the vegetation during the period is likely forest.Comparing with the pollen analysis,the vegetation type of paleosol S₀,S₁,S₄,S₈,S₉ which δ¹³C content is-5.85‰^-10.00‰,is forest-grass.δ¹³C content of paleosol S₂、S₃、S₆、S₇ is-8.72‰～-6.95‰,their vegetation is grass.The loess layer L₁、L₂、L₅、L₆、L₈、L₉ represent the severe cold-dry glacial period with δ¹³C content of-3.7‰～-2.27‰,their vegetation belonging to steppe-desert.

Key words: loess, carbon isotope, paleo-vegetation, spore-pollen