中文摘要：

本文对罗布泊深220cm的DHX剖面沉积物元素、粒度、TOC （总有机碳）、C/N （总有机碳/总有机氮）分析。利用AMS 14C测年结果建立年代框架，探讨了晚冰期至中全新世环境演变特征及气候快速变化事件。结果显示气候环境经历了5个演变阶段：1）晚冰期（12.8～11.4cal.ka B.P.）罗布泊地区以物理风化为主，气低温，流水携带外来有机质少，湖泊水动力小。这可能是太阳辐射低、热带辐合带（ITCZ）纬度位置较低形成的。2）全新世11.4～9.6cal.ka B.P.期间，罗布泊地区以化学风化为主，流水携带外来有机质增加，气温升高，气候暖湿。这可能是夏季太阳辐射高，冬季太阳辐射低，热带辐合带位置北移，导致全年冰雪融水或山地降水增加、蒸发少，全年水分盈余，气候湿润。3）9.6～8.2cal.ka B.P.期间以化学风化为主，流水携带外来有机质减少，各指标指示湖泊水位波动明显，这可能是热带辐合带位置波动的结果。4）8.2～6.7cal.ka B.P.期间气候暖湿，以化学风化为主，此时段热带辐合带北移，季风仍较强，罗布泊源区昆仑山受其影响降水多，罗布泊来水增加气候相对湿润。5）6.7～5.5cal.ka B.P.期间水动力增加，气候逐渐变干，这可能是热带辐合带南移，夏季太阳辐射降低，冰雪融水量减少，冬季太阳辐射增强蒸发量增加引起的。其中，罗布泊大约在11.0cal.ka B.P.、10.0cal.ka B.P.、9.3cal.ka B.P.、8.4cal.ka B.P.、7.0cal.ka B.P.和5.8～5.5cal.ka B.P.期间出现了一系列气候干旱事件。罗布泊DHX剖面记录的这些气候事件在本区及其他地区也被广泛记录，并与格陵兰冰芯及北大西洋地区降温、热带辐合带南移、季风减弱一致，反映了此区在响应全球变化过程中既有区域特点，也有广泛的一致性特征。说明罗布泊地区对全球环境变化非常敏感并受控于全球变化。

英文摘要：

Lop Nur is located in the northeastern area of the Tarim Basin, Xinjiang Uygur Autonomous Region, Northwestern China. A 2.2-m-deep trench profile has been taken in the center of the Lop Nur and named DHX（40°07＇40.18″N, 90°28＇51.77″E）. The chronology of the section was determined based on AMS 14C dating. Element, grain size, total organic matter（TOC）, C/N（total organic matter/total organic nitrogen）were used to reconstruct the environmental sequence and climate events from the Late Glacial to Middle Holocene. The environmental changes in the Lop Nur region can be divided into five stages based on significant changes in the multi-proxy assemblages. During Late Glacial（12.8～11.4cal.ka B.P.）the values of grain size components Md, C1, C2 and C3 were low which demonstrate a low water dynamistic. The low TOC and C/N values indicate a little amount of organic material from sediment basin. The highest Rb/Sr value show physical weathering dominates this stage. The high Fe/Mn values together with low Mg/Ca indicate cold climate and low lake level. The multi-proxy indicates dry climate dominates this stage. May be the ITCZ（intertropical convergence zone）location more south and low insolation triggered low snow and ice melt or precipitation in the mountains. From 11.4cal.ka B.P. to 9.6cal.ka B.P., the Rb/Sr value decrease which demonstrates the chemical weathering dominates this stage. TOC and C/N values increase show more organic material from sediment basin. The low Fe/Mn values together with high Mg/Ca show temperatures increasing and wet climate appear in Early Holocene. This warm wet stage may caused by insolation values high in summer and low in winter and the ITCZ move north induced deglaciation. During 9.6～8.2cal.ka B.P. the obviously fluctuation of Fe/Mn, Mg/Ca and TOC values may be triggered by fluctuation of the ITCZ position. Between 8.2～6.7cal.ka B.P. warm wet climate appear. Chemical weathering still dominates this stage. May be the warm wet climate controlled by strengthening