中文摘要：

研究了西藏色卡执盐湖一个670cm厚的钻孔SZK剖面中微体古生物包含的古环境信息,探讨湖区近22ka以来环境气候的演变。SZK孔剖面含有丰富的介形类,但分异度较低,计有4属8种。据其在地层中的分布特征,将其划分为8个组合。根据这些组合及生态特征,结合U系和14C测年,发现色卡执湖区在近22ka以来经历了几次较大的气候和环境变动：①22060～15070aB.P.,湖水浅、水温低、气候较冷湿;②15070～12425aB.P.,湖面扩大抬升,水温回升,气候转暖湿;③12425～10010aB.P.,湖面下降,水温低,气候寒冷,其中10600～10010aB.P.期间,气候突然变冷,为全球新仙女木寒冷事件在本区的反应;④10010～7550aB.P.,湖盆水量增加,气候冷湿;⑤7550～6730aB.P.,湖水温度继续回升,气候转暖湿;⑥6730～5760aB.P.,湖面下降,气候趋于干冷;⑦5760～4750aB.P.,湖盆发育晚期、气候干冷。

英文摘要：

The paper deals with the climatic evolution since 22 ka BP in the Sêkazhig Lake area,Tibet.By studying a 670 cm thick section of hole SZK,a great deal of paleoenvironmental information has been obtained based on the microfossil record there.The section contains plenty of ostracod fossils,but their diversity is comparatively low.The fossils comprise 8 species in 4 genera and are grouped into 8 assemblages according to their distribution in strata.Their ecological features,combined with U-series and 14C dating,reveal that the lake area has undergone several great changes in climate and environment since nearly 22 ka BP：① 22,060~15,070 a BP：the lake was shallow with low water temperatures,and the climate was cold and wet;② 15,070~12,425 a B.P.：the climate got warm and wet,and the lake was enlarged and uplifted with rising water temperatures;③ 12,425~10,010 a BP：the lake water table went down with low water temperatures again,and the climate was cold,and during the period of 11,585~10,920 a BP the climate became cold suddenly in response to the Younger Dryas cold event;④ 10,010~7550 a BP：the climate was cold and wet,and the lake was enlarged again;⑤ 7550~6730 a BP：the climate turned warm and wet,and the water temperatures kept rising;⑥ 6730～5760 a BP：the water level lowered and the climate tended to be cold and dry;⑦ 5760~4750 a BP：the climate kept cold and dry,and the lake was in the late stage of its development.