西伯利亚黄土环境磁学机制探讨

中国黄土 环境磁学 西伯利亚黄土 古气候变化 磁化率
刘秀铭 2008-01 项目
【英文摘要】Research in Chinese loess has achieved a great success in East Asian Monsoon and global climatic change, it has also revealed a positive relationship between magnetic susceptibility of loess paleosol sequences and paleoclimatic warm and humidity (paleosol pedogenic development). The magnetic susceptibility now has became a regular parameter widely used by Quaternary scientists, but at the same time following quite a few questions reported. However in Siberia, Kurtak loess stratigraphy exhibits a negative relation, providing a excellent profile for comparison. In order to correctly recognise and reconstruct paleoclimate, this research is going to measure various climatic proxy from sections in Siberia for the last interglacial cycle for searching mechanism of the location responding to westley and winter monsoon and its relationship with the Loess Plateau. In addition, by comparing magnetic properties of loess and soils in both Siberia and Loess Plateau, the main aim is to exam the mechanism of the susceptibility as a proxy of summer monsoon, in order to find out the reason why magnetic susceptibility corresponding to pedogenic developement shows completely different in these two locations. This study is going to research suitable ranges for positive, negative and no relations, its results will guide the susceptibility users how to correctly apply this parameter as a climatic proxy - - one of most basic scientific problems within paleoclimatic environmental research over the world.
【中文摘要】中国黄土在东亚季风和全球变化研究方面取得了极大成就,也揭示了中国黄土地层磁化率与成土古气候温湿程度(古土壤成土强度)基本成正比例关系,如今磁化率已成为一个常规指示参数广为应用,同时也有不少问题的报道。而在西伯利亚Kurtak 地区黄土地层中,这个关系却呈反比,提供了绝好的对比剖面。本研究拟对西伯利亚末次间冰期旋回黄土剖面各气候代用指标进行详细测量,以求正确认识和重建古气候环境,探讨当地对西风和冬季风的响应机制以及与中国黄土高原的关系。除此以外,通过比较中国和西伯利亚黄土-古土壤的磁学性质,还要重点检验磁化率作为黄土古气候夏季风代用指标的机理,以求找出两地磁化率与古土壤发育对应关系完全不同的原因。试图确立两者的正相关,负相关以至不相关的应用范围,并以本研究的结果来指导在第四纪研究中正确地应用磁化率代用指标——一个在世界范围内古气候环境研究中具有普遍意义的科学问题。