摘要
Holocene palaeoweathering conditions and environmental changes of Loulan （楼兰） Stupa Sec-tion were reconstructed by major elements analysis results and optical stimulated luminescence dating results. Major element results show source rock change little, with the composition equivalent to granodiorite. The low R value and high CIA （chemical index of alteration） value indicating the section at primary weathering phases. The muddy silt and silty clay have low R value and high CIA value and total iron content. In contrast, the sandy clay silt and sandy silt have high R value and low CIA and total iron value. Deglaciation time climate was relatively humid. In comparison to previous and posterior hiatus, the Middle-Holocene climate was relatively wet but still displayed high-frequency and high-amplitude fluctuations.
Holocene palaeoweathering conditions and environmental changes of Loulan （楼兰） Stupa Sec-tion were reconstructed by major elements analysis results and optical stimulated luminescence dating results. Major element results show source rock change little, with the composition equivalent to granodiorite. The low R value and high CIA （chemical index of alteration） value indicating the section at primary weathering phases. The muddy silt and silty clay have low R value and high CIA value and total iron content. In contrast, the sandy clay silt and sandy silt have high R value and low CIA and total iron value. Deglaciation time climate was relatively humid. In comparison to previous and posterior hiatus, the Middle-Holocene climate was relatively wet but still displayed high-frequency and high-amplitude fluctuations.
基金
supported by the Key Consultation Project (No. 2008-ZD-05)of Chinese Academy of Engineering
the National Natural Science Foundation of China (Nos. 40472094, 40772212)
National Project (No. NP2010-033)
