基于粒度建立1.2 Ma长武黄土剖面高分辨率时间标尺

Establishment of the Changwu Loess Section Stacked 1.2Ma High Precision Timescale Based on Grain Size

中国黄土-古土壤堆积作为研究全球古气候古环境变化的三大支柱之一,清晰地记录了第四纪时期气候的干冷与暖湿变化.若对其所蕴含的全球变化信息进行更精确地研究,需要高分辨的时间标尺作为研究基础.本文以长武黄土-古土壤剖面为研究对象,通过将黄土-古土壤磁化率变化曲线与深海氧同位素变化曲线对比获得年龄控制点,以其>32μm颗粒含量作为变量,利用粒度内插方法建立黄土时间标尺.并利用两种方法加以验证,获得了一条可靠的高分辨率的黄土-古土壤时间序列.

As one of the important pillar of the global paleoclimatic change research,loess-paleosol deposit in China had a clear record of winter and summer monsoon during Quaternary. A high precision,high resolution timescale of loess in China is the basis of research of paleoenvironmental chang. In this paper,a high precision timescale based on 〉32 μm size fraction of Changwu loess section is established by grain size model. Positions and time of time control points is obtained by contrasting with LR04 δ18 O. Two methods are both used to verify accuracy of this timescale. The result shows that the timescale which Established by the method is reliable.