Comparisons of red ratings (RR) with Fed, Fed/Fet, clay content, and magnetic susceptibility (X) of two loess-paleosol sequences at Luochuan and Lingtai on China's Loess Plateau were conducted to study the possibl...Comparisons of red ratings (RR) with Fed, Fed/Fet, clay content, and magnetic susceptibility (X) of two loess-paleosol sequences at Luochuan and Lingtai on China's Loess Plateau were conducted to study the possible relationship between RR and pedogenic degrees of the two loess-paleosol sequences, and to discuss whether the RR could become new paleo-climatic indicators. Results showed that the RR of the two loess-paleosol sequences had positive, highly significant (P ＜ 0.01)correlations with: 1) citrate-bicarbonate-dithionite (CBD) extracted iron (Fed), 2) ratios of CBD extracted iron to total iron (Fed/Fet), 3) clay (＜ 2 μm), and 4) magnetic susceptibility (X). This suggested that the RR of these loess-paleosol sequences could indicate degrees of loess weathering and pedogenesis and were potential paleo-climatic proxies. The strong correlations of RR to Fed and X also implied that during pedogenic processes, pedogenic hematite in loess and paleosols were closely related to the amount of total secondary iron oxides and pedogenic ferrimagnetic minerals (predominantly maghemite).展开更多
基金Project supported by the National Natural Science Foundation of China (No. 40101013) the Outstanding Overseas Chinese Scholars Fund of the Chinese Academy of Sciences (No. 2003-1-7).
文摘Comparisons of red ratings (RR) with Fed, Fed/Fet, clay content, and magnetic susceptibility (X) of two loess-paleosol sequences at Luochuan and Lingtai on China's Loess Plateau were conducted to study the possible relationship between RR and pedogenic degrees of the two loess-paleosol sequences, and to discuss whether the RR could become new paleo-climatic indicators. Results showed that the RR of the two loess-paleosol sequences had positive, highly significant (P ＜ 0.01)correlations with: 1) citrate-bicarbonate-dithionite (CBD) extracted iron (Fed), 2) ratios of CBD extracted iron to total iron (Fed/Fet), 3) clay (＜ 2 μm), and 4) magnetic susceptibility (X). This suggested that the RR of these loess-paleosol sequences could indicate degrees of loess weathering and pedogenesis and were potential paleo-climatic proxies. The strong correlations of RR to Fed and X also implied that during pedogenic processes, pedogenic hematite in loess and paleosols were closely related to the amount of total secondary iron oxides and pedogenic ferrimagnetic minerals (predominantly maghemite).
