西昆仑山南麓湖泊和水系的近期变化

西昆仑山南麓湖泊50 000年来曾经过多次扩张和收缩,其中高湖面出现在46 000 a B.P.前后和39 000—24 000、22 000—18 500、16 000—13 000、11 000—9 000 a B.P.。本区曾经是一个统一大湖,因气候变干、水面下降而分割成目前的湖泊。高湖面出现的时间与间冰段相当,但10 000年来由于气候不断变干而未出现全新世南湖面。据沿岸多级砂砾堤推算,9 000年来的气候变化具有400a和800a的周期。本区河流原属喀拉喀什河上游,因地壳上升和气候变干而分割成目前郭扎错、阿克赛钦湖和苦水湖三个封闭水系。

THE RECENT CHANGES OF LAKES AND DRAINAGE SYSTEMS IN THE SOUTH PIEDMONT OF WEST KUNLUN MTS., CHINA

West Kunlun Mts. is one of the centers of present-day glaciers in China. Glaciers, lakes, and drainage system in the region have changed greatly since the middle late-Pleistocene as the global climate changing and the Qinghai-Xizang Plateau rising. Radiocarbon dates of lacustrine sediments and geomorphological survey of the ancient lake shorelines show that the lakes in the south piedment of West Kunlun Mts. have suffered strong drops of water level and separated into a number of small ones in the past 50 000 a. However, these lake level drops were fluctuating, and high level status in the following time periods, around 46 000, 39 000—24 000, 22 000—18 500, 16 000—13 000, 11 000—9 000, 6 000 and 4 500-3 500 a B.P. are identified.Streams in the piedmont region were parts of the upper reach of the Kalakashew River, a side river of the Hetian River in the early time, then changed into interior rivers as Kunlun Mts. rising and climate becoming drier.