云南高原典型湖泊现代过程及环境演变研究进展

A STUDY REVIEW ON THE MODERN PROCESSES AND ENVIRONMENTAL EVOLUTION OF THE TYPICAL LAKES IN YUNNAN

对云南省境内从南到北、由低至高分布的7个典型湖泊进行钻探取样,共钻取岩芯140m,同时对部分湖泊采集了表泥样品。对湖区古湖岸阶地、层状地貌和相关地层考察研究表明:主要存在着2～3次明显的高湖岸,高湖岸已受构造作用的强烈影响发生变形;杞麓湖、拉市海、文海等分布着高于落水洞时代很新的多层贝壳层,蛇山组沉积结束于末次冰期晚期及其它相关证据说明,该区现代水系可能是最近几万年才最终形成。

This paper shows the primary results of the systematic investigations and sediment core collecting and sampling on 7 carefully chosen typical lakes , which distributed from south to North Yunnan, ranging from the low latitudes to the high latitudes during the field work season lasting from April to May, 2004. About 140 m long cores totally have been collected from drilled on 7 lakes. At the same time, the lake top samples have also been collected from some of the lakes. The investigation results on the paleaoterraces, stepped landforms and related landscapes reveal that there exist 2 to 3 high lake terraces in the study areas; typically there exist at least 3 high lake level stands, which had been strongly influenced by the neo-tectonics, around Qilu Lake in Tonghai. The Xingyun Lake naturally connected with Fuxian Lake during the high water level stages; The modern lake situation of the Lashihai has been controlled by the neotectonics and its connection with the Wenhai Lake, which situated at the higher altitudethan Lashilake, and the lower altitude river, Lijiang through the under ground river is mostly a recent event. It can be deduced that the drainage systems in the study area just came to exist since late Pleistocene.