中文摘要：

选择青藏高原南部邛多江盆地湖相沉积物为研究对象，利用AMS14C测年手段，建立邛多江盆地湖相沉积物40kaBP～30kaBP的时间序列。对采自5cm～250cm湖相沉积物中的50件样品进行总有机碳（TOC）含量、总氮（TN），TOC／TN比值和有机碳同位素（δ13C）等环境代用指标的测试分析，将邛多江盆地40kaBP-30kaBP期间的古气候划分为如下几个阶段：气候暖湿期（40．2kaBP～38．5kaBP）、气候温干期（38．5kaBP～35．4kaBP）、气候过渡期（35．4kaBP～32．4kaBP）、气候动荡期（32．4kaBP～31．7kaBP）和气候转干期（31．7kaBP～30．3kaBP）；经频谱分析表明，研究区存在1552a，1187a，961a，602a，538a和492a气候变化的准周期，千年尺度的气候变化可能与太阳活动、大气环流、大洋内部不稳定因素的影响及季风的活动周期有关，识别出的538a周期与太阳活动的530a周期相对应，可能表明太阳活动也是影响藏南邛多江盆地气候变化的原因之一。

英文摘要：

The lacustrine sediments of Qiongduo Basin in the southern Qinghai-Tibet Plateau are studied by using AMS14C dating method,and the time series of 40 ka BP-30 ka BP of Qiongduo- jiang basin sediments is obtained. The TOC content, TN, the TOC/TN ratio and δ13 Corg substi- tute indexes from 50 samples of 5 cm-250 cm Qiongduoliang Basin lacustrine sediments are analyzed,and the paleoclimate change of 40 ka BP-30 ka BP in Qiongduojiang Basin is divided into several stages： the warm humid climate period （40.2 ka BP-38.5 ka BP） ,the warm arid climate period （38.5 ka BP-35.4 ka BP）, the transition climate period （35.4 ka BP-32.4 ka BP） ,the volatility climate period （32.4 ka BP~31.7 ka BP） and shift to arid climate period （31.7 ka BP- 30.3 ka BP）. Spectrum analysis reveals that there are quasi-periodic climate variations of 1 552 a, 1 187 a,961 a,602 a, 538 a and 492 a from 40 ka BP-30 ka BP. Climate change at the millennium scale may be related to the effects of solar activity, atmospheric circulation, oceanic internal instability and monsoon activity. The identified 538 a cycle corresponds to the 530 a cycles of the solar activity, and therefore,the solar activity is also one of the causes of climate change in the Qong- duojiang basin.