末次间冰期—末次冰期可可西里地区气候演化形式  

Climatic changes between the last interglacial age and the last glacial age in Hoh Xil area

作　　者：田庆春[1] 杨太保[2] 石培宏[3] 

机构地区：[1]山西师范大学地理科学学院,临汾041000 [2]兰州大学资源环境学院冰川与生态地理研究所,兰州730000 [3]陕西师范大学旅游与环境学院,西安710119

出　　处：《地理研究》2017年第2期336-344,共9页Geographical Research

基　　金：国家自然科学基金项目(40871057;41401226)

摘　　要：选择青藏高原腹地可可西里地区为研究区,通过对湖泊沉积物色度、磁化率、总有机碳和粒度等分析,对可可西里地区末次间冰期以来的气候演变形式进行了恢复,其演化阶段大致可以与深海氧同位素进行对比。可可西里地区气候变化既表现出与全球气候变化一致的特点,也存在着独特的区域特征。末次间冰期气候波动可以和深海氧同位素相比,也可划分出5个亚段,但两者的波动形式存在差异,深海氧同位素指示5e最暖,而本区气候可能在5a暖湿配置最好;末次冰期气候环境整体较差,只有在间冰阶湖泊水体略有增大,总有机碳也呈小的峰值,色度和磁化率的峰值较高,对应于3c和3a的两个暖期,说明此时段较为温暖,但湿度较差。可能受到构造运动的影响湖泊水体缩小,水动力增大的缘故,相应的沉积条件较差,导致总有机碳含量较低。其他时段各指标均为低值显示气候较为寒冷,只出现一些小的峰值可能与Dansgaard-Oeschger旋回一致。直至1万年以来,各指标呈增大趋势,可能与全新世气候增暖湿有关。In this study, Hoh Xil area, the hinterland of the Tibetan Plateau, was taken as the research area. The climate evolution in Hoh Xil since the last interglacial age was reconstrcted by analyzing colour, magnetic susceptibility, total organic carbon（TOC）, and grain size of lacustrine sediments. Compared with Marine Isotope Stages（MIS）, there was both a good agreement with climate evolution from other areas in the world and unique local characteristics. Similar to MIS5, climate change during the last interglacial age can be classified into five sub- stages, but the phases were not an exact match with each other.According to our results, the warmest period occurred during MIS5 a instead of MIS5 e. Overall,there was no warm and humid climate and environment during the last glacial age unless the interstage of the last glaciation. In this period, low TOC content and high peaks of colour and magnetic susceptibility indicated that lake level rose slightly. So it possibly corresponded to the periods of MIS3 c and 3a with warm and dry climate. Perhaps due to shrinkage of the water body and increased hydrodynamic force as a result of the strong tectonic movement, the deposition conditions deteriorated and TOC content decreased. Low values of proxies during other periods indicated a cold climate. In these periods, the occurrence of some peaks of high values was consistent with the Dansgaard- Oeschger cycle. High values of climate indicators could be attributed to the warmer Holocene since 10,000 years ago.

关 键 词：末次间冰期 末次冰期 可可西里 气候演化 

分 类 号：P532[天文地球—古生物学与地层学]