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对山陕峡谷张家湾村蔚汾河阶地上沉积的黄土地层粒度—磁化率进行分析发现:沉积物的粒度—磁化率变化曲线能够很好地反映黄土—古土壤地层序列的变化.粒径小于5μm和大于40μm组份的体积分数曲线分别是夏季风和冬季风的良好替代性指标,通过粒度分析所绘制的各粒级组份体积分数曲线显示,古土壤S2、S1和Sm发育时期,东亚夏季风加强,粒径小于5μm组份的体积分数增大;黄土L2和L1堆积时期,冬季风有所加强,粒径大于40μm组份的体积分数增大.张家湾剖面的黄土记录只能在万年尺度上与深海氧同位素记录进行对比,整体上反映了最近230ka以来山陕峡谷东亚季风的演化过程.
The analysis of the grain size-susceptibility of loess strata deposited on the ground of the Wei-Fen River in the Zhangjiawan Village, Shan Shan Gorge, shows that the grain-to-susceptibility curve of the sediment can well reflect the variation of the sequence of the loess-paleosol strata. The volume fraction curves of the components smaller than 5μm and larger than 40μm are the good alternative indexes of summer monsoon and winter monsoon respectively. The curve of the volume fractions of the fractions by the particle size analysis shows that during the development of S2, S1 and Sm, The East Asian summer monsoon intensified, and the volume fraction of the particles smaller than 5μm increased. The winter monsoon intensified when the loess L2 and L1 accumulate, and the volume fraction of the particles larger than 40μm increased. Which can be compared with the deep-sea oxygen isotope records on a multi-year scale, and reflect the evolution of the East Asian monsoon in the Shan-Shan Gorge since the last 230 ka.