作　　者： ; ; ; ; ; ; ;

机构地区： 华南师范大学地理科学学院

出　　处： 《中国沙漠》 2006年第3期341-344,共4页

摘　　要： 萨拉乌苏河流域米浪沟湾剖面末次间冰期层系记录了8．5个有风成的古沙丘砂与河湖相和／或古土壤构成的沉积旋回。该层系Rb、Sr元素含量分布具有明显的规律，主要表现为古沙丘砂中的Rb、Sr含量相对迁移，而在上覆河湖干目和／或古土壤中相对聚集，构成术次问冰期的Rb、Sr含量迁移与聚集的8．5个元素旋回。研究表明，由Rb、Sr含量变化构成的这些旋回主要是由干冷暖湿气候波动所致。该地末次间冰期层系由上至下可划分为5个层段，即MS1～MS5。Rb、Sr含量在MSl、MS3、MS5和MS2、MS4分别呈现明显的峰态和不同程度的低谷，揭示出前者与后者分别是受到暖湿和干冷气候影响向的阶段。据此，可以将MS1、MS2、MS3、MS4和MS5依次在气候性质和阶段上可与GRIP冰芯和Sulu海MIS5a、5b、5c、5d、5e诸亚段进行对比。研究亦表明，河湖相和古土壤Rb／Sr曲线却都不尽是峰态，黄土高原Rb／Sr值的气候意义并不完全适宜说明半干早盆地或洼地的古环境变化。 The Last Interglacial Period strata in the Milanggouwan section in the Salawusu River valley on the Ordos Plateau, China, have 8.5 sedimentary cycles composed alternately of eolian dune sands, fluvio-lacustrine facies and/or paleosols. The distributing regularity of Rb, Sr element content was that they transplanted relatively in the eolian dune sands and accumulating relatively in the fluvio-lacustrine facies and/or paleosols, composing 8.5 cycles of Rb, Sr elements moving and accumulating in the Last Interglacial Period in the study region. The study showed that these cycles were chiefly resulted from dry-cold and warm-humid climate fluctuations. The stratigraphical sequences during the last interglacial period can be further divided into 5 phases from top to bottom, among which the Rb, Sr content showed peaks in MS1, MS3, MS5 influenced by warm-humid climate, and showed low values in MS2, MS4 influenced by dry-cold climate. Hereby, viewed from climate feature and variation phases, MS1, MS2, MS3, MS4 and MS5 might successively correspond to the sub-stages, MISSa, MISSb, MISSc, MIS5d and MISSe in GRIP Ice Core and Sulu Sea. The study also showed that the Rb/Sr curves are not all peaks in fluvio-lacustrine facies and paleosols, so the climate significance of Rb/Sr value on the Loess Plateau can not completely explain the changes of ancient environment evolving in semiarid basin or depression in our country.

关 键 词： 末次间冰期 米浪沟湾 和 盆地及洼地

领　　域： [天文地球] [天文地球]