湖泊沉积物中S、C及其比值的环境意义

S, C AND OC/TS IN LAKE SEDIMENTS AND THEIR ENVIRONMENTAL SIGNIFICANCE

本文以浅淡水湖固城湖和微咸水湖岱海为例,研究沉积物中有机碳、总硫和其比值(OC/TS)的垂向分布规律及其沉积环境(沉积时期的气候冷暖及干湿变化等)、古盐度及环境污染等方面的意义。固城湖沉积物的氧化还原交界面(5cm深处)上硫高碳低,OC/TS突然变小。岱海在高水位年代OC/TS增高,低水位年则降低,分别属于冷湿和冷干气候条件下的沉积特征。论证了OC/TS指标从海洋沉积研究移植到湖泊沉积研究的可用性及其应用前景。

Gucheng Lake, a fresh shallow lake, and Daihai Lake, a brackish lake, are examplified to study the vertical distribution of organic carbon, total sulphur, and their ratio(OC/TS) in lake sediment, and their meanings in lake sedimental environment (climatic change in sedimental periods), palaeosalinity as well as environmental pollution. It is found that OC/TS decreases abruptly on the redox interface (5cm deep) of the sediment in Gucheng Lake, with high content sulphur and low carbon while increases when Daihai Lake was in its high lake level, and decreases in its low lake level corresponding with the sedimentary characteristics under the climate of cold-wet and cold-dry respectively. The index (OC/TS) originally used in oceanic sedimentary research is shown in this paper the possibility of its application in limnological sedimentary research.