萨拉乌苏河流域微量元素揭示的气候变化

Climate Change Indicated by Trace Elements in Salawusu River Basin

根据毛乌素沙漠东南缘萨拉乌苏河流域滴哨沟湾削面中更新世晚期以来风成砂与河湖相互为叠覆的沉积记录，利用SPSS软件对P、V、Cr等16种微量元素及Rb／Sr和Sr／Ba比值进行了聚类和相关分析。结果表明：除Sr、Ba、Rb／Sr和Sr／Ba之外的P、V、Cr等14中微量元素反映的气候变化规律较好，其含量的峰值段对应河湖相沉积，而谷值段对应风成砂沉积。根据微量元素含量变化特征及其与地层的对应关系，将萨拉乌苏河流域中更新世晚期以来的气候变化划分为5个阶段：223～196kaBP，气候温暖湿润，相当于黄土高原S2古土壤发育期；196～148kaBP，气候干冷，相当于黄上高原L2黄土发育期，属倒数第二次冰期；148～75kaBP，气候温暖湿润，对应末次间冰期；75～10kaBP，气候干冷，对应末次冰期；10kaBP以来，气候以温湿为主。各个阶段还有气候冷暖干湿波动变化。通过与深海氧同位素阶段，冰芯记录变化对比，发现本区气候变化与全球变化具有较好的一致性。

Salawusu river basin is in the southeast of the Mu Us Desert, and lies between desert and the Loess plateau and is sensitive to climate changes. Firstly, there are analyses of Hierarchical cluster and correlation of 16 trace elements（P.V,Cr.Mn.Co. Ni.Cu.Zn,Pb,As,Rb.Y,Zr.Sr.Ba and Nb） and Rb/Sr and Sr/Ba in Dishaogouwan section. As a result, climate change that Sr.Ba,Rb/Sr and Sr/Ba explain is not well. So the papers analyzes the climate changes according to the content of trace elements（P.V,Cr.Mn,Co,Ni.Cu,Zn,Pb.As,Rb.Y.Zr and Nb） . According to the content and variation of trace elements, the climate change can be divided into 5 stages： （223- 196）ka BP, warm and humid, and in the pace with palaeosol S2 ;（ 196- 148）ka BP, cold and arid, and in the pace with Loess L2 and belonging to Last Second Glacial ; （ 148- 75 ） ka BP, warm and humid , and in the pace with Last Interglacial; （75-10）ka BP, cold and arid, and corresponding of Last Glacial and 10 ka BP to present, warm and humid, but the climate is ariding. The papers also makes contrast between the variation of trace elements of different time and oxygen isotope phases of deep sea and mainland ice cores. The result shows that the climate change in the Salawusu River area is consistent with the global change.