黄土高原第四纪粉尘沉积速率的时空变化及其意义

本文系统地计算了黄土高原洛川、西峰、宝鸡、西安刘家坡、兰州九洲台、西宁大墩岭黄土剖面的粉尘沉积速率，发现粉尘沉积速率除随冰期、间冰期具有明显波动外，还呈现时间上由老向新的阶段性升高，空间上由西北向东南降低的总体趋势。第四纪以来，黄土高原粉尘沉积速率出现了几次异常增高的时期，它们与青藏高原隆起时段相吻合。距今约70万年，该区冬季风出现重大调整，冬季风风力明显的逐步增强，风向偏转到NW方向。粉尘沉积速率可作为我国冬季风强弱变化的较好指标。

Temporal and Spatial Variations of the Loess Accumulation Rate and Its Significance on the Loess Plateau During Quaternary

The loess accumulation rates of Liujiapo, Luochuan, Xifeng, Baoji, Jiuzhoutai and Dadunling sections on the loess plateau were systematically studied in this paper. It was found that the loess accumulation rates have increased step by step from past to present,and decreased from NW to SE in the same fashion, besides,the variation from glacial to interglacial epoches. There were several periods of extremely high rates of the loess accumulation during Quaternary, which are coincided with the uplift events of the Qinghai-Tibetan Plateau. At about 0. 7 MaBP,the winter monsoon had a remarkable change both in wind direction and intensity. Since then,the intensity of winter monsoon has become stronger and stronger,while the direction of winter monsoon has changed to northwest. This paper proved that the loess accumulation rate can be considered as one of the best indices to indicate the winter monsoon variations of the Loess Plateau.