摘要
根据西昆仓山南坡湖盆区古湖相地层的分布和地层变化以及^(14)C 测年资料,阐述了湖泊的演变历史及其原因。指出该区湖泊变化经历了如下几个过程:统一大湖分裂的若干小湖→高湖面期→湖面降低→高潮面期→湖面降低→湖泊大幅度萎缩.其湖泊演化是青藏高原的构造隆升和全球性气候变化二者共同作用的结果。
Based on field investigation and data obtained from more than 100 samples analyses in the laboratory,the characteristics of lacustrine deposit and the distribution,genesis and evolution of lakes on the south slope of the West Kunlun Mountains are discussed from the viewpoint of sedim- entary stratigraphy and stratigraphic chronology. Lakes on the south side of the West Kunlun Mountains are distri- buted in depression basins along a wide east-west tectonic valley.The water source comes from melted ice and snow.The genesis of the lakes is tectonic pattern. By analyzing lacustrine sedimentary stratigraphic features,Tianshui- hai paleolake might have existed since the early Quaternary.Guozha Lake,Aksayqin Lake,Tianshuihai Lake and North Tianshuihai Lake were connected together at that time.The deposit model is an up- accumlation pattern.Up to the late period of the Late Pleistocene,the unified paleolake had been separated and disappeared gradually,several lakes were formed.A period with high lake level existed about 36000yr. B.P.After 30000 yr.B.P.the lake level declined.About 21000 yr.B.P. the lake level rose again.In the western part of North Tianshuihai Lake about 4800m above sea level,there is a lake terrace about 40m higher than today's lake level.On the southeast side of Guozha Lake about 5080m above sea level,there js also a lake terrace 3m above the existing lake level.During the Holocene,lakes shrank by stages,presented byseve- ral cirlular lake terraces or lakeshore traces.
出处
《地理科学》
CSSCI
CSCD
北大核心
1991年第4期306-314,共9页
Scientia Geographica Sinica
关键词
湖相
沉积
湖泊
演化
昆仑山
Lake evolution
Lacustrine deposit
West Kunlun Mountains
