摘要
中国的陆相黄土地层连续地记录了第四纪以来的古气候变化。基于中国黄土磁化率曲线与深海氧同位素记录具有可比性这一事实，磁化率作为一种气候替代性指标在黄土研究中得到广泛的应用。但是，磁化率的物理意义仍不清楚。本文作者对陕西榆林蔡家沟剖面末次间冰期以来的风成沉积作了研究，指出黄土、古土壤的磁化率差异不仅与前人提出的碳酸盐淋失、空隙度变化、＂就地＂新生成磁性矿物等作用有关，而且还可能与有机质有重要关系。有机质中的铁细菌可能对磁化率有重要贡献。
Chinese loess deposits continuously documents the Quaternary climatic changes. Because the loess magnetic susceptibility curve can be correlated with the marine oxygen isotope records very well. it has been considered as one of the climatic proxy data and widely used in the study of Chinese loess. The physical mechanism of the magnetic susceptibility, however, remains as an enigma. Here, based on the study of the magnetic susceptibility and organic matter content of the eolian sediments over the last climatic cycle from Caijiagou profile, the authors suggest that the variations of susceptibility in loess-palaeosol sequences are not only influenced by pedogenic process. but also affected by the organic material. The iron bacterium, especially the magnetotactic bacterium prob make substantial contributions to the increasing of the magnetic susceptibility.
出处
《地球物理学进展》
CSCD
1995年第4期88-93,共6页
Progress in Geophysics
基金
国家自然科学基金
