中文摘要：

通过对羌塘地区中部羌D1井长181．6m第四系岩芯的研究，分析湖泊沉积记录的岩相旋回和Fe／Mn和Sr／Ba等微量元素古环境参数的变化，结合样品的热释光（TL）测年数据，讨论晚更新世该区湖泊扩张和湖面升降变化过程。结果表明，晚更新世以来该区湖泊环境的演化，经历了二次湖进过程，二次湖平面上升期之间出现了一次广泛的干化低水位时期。其中15～7万年期间的湖泛事件可以在区域上进行追踪对比，它对应于深海氧同位素的第5阶段，可以作为高原中央气候转型期的标志。

英文摘要：

A lacustrine core 181.6 m long from weii Qiang D1 in the Qiangtang area of the central Tibetan plateau is studied. Lithofacies cycles and paieoenvironmental indices such as Fe/Mn and Sr/Ba ratios are analyzed, and ages of the corse were determined based on TL methods. Lake expansion and level fluctuations in the late Pleistocene are discussed. The lacustrine succession indicates two significant periods of high water levels asso- ciated with an extensive low water level during a dry climatic interval. The second lake expansion event during 150--70 ka can be traced across these regions, which corresponds to the fifth stage of the deep sea oxygen isotope stratigraphic record, and represents a critical period of paieociimatic change in the central Tibetan plateau.