博斯腾湖现代沉积特征及其环境意义

在新疆博斯腾湖黄水湾采得27 cm浅钻样品，对其作相应的地球化学指标分析，对比近年来焉耆站的气象资料，认为26～11 cm段（90 a前至1980年左右）较好地记录了当时的气候变化，即博斯腾湖流域首先经历了气候变干、蒸发作用增强的转变，随后逐渐出现气候回暖变湿的信号。11 cm往上（近40 a来）由于人类活动的干扰，外来物源的直接输入和工农业排污引起的富营养化等问题，使影响有机质及碳酸盐同位素组成的主导因素改变，从而扰乱了湖泊沉积物记录气候变化的功能。

Modern Sedimentation and Its Environmental Significance of the Bosten Lake

In this paper,the geochemical indicators of 27-cm shallow core samples collected from the Huangshui area in the Bosten Lake Basin were analyzed,their values were compared with the meteorological data observed by Yanqi Meteorological Station,and the environmental significance of modern sedimentation was discussed.The results show that climate change at that time(from 90 years ago to around 1980) was recorded well by the core samples at depth of 26-11 cm,that is,a dry climate change and an evaporation increase occurred at first,and then it became warmer with precipitation increase.The dominant factors of isotopic composition of organic matter and carbonate were changed due to the disturbance of human activities,input of external material sources and the eutrophication caused by industrial and agricultural sewage drainage in recent 40 years,thus the function of sediments in recording climate change was disrupted.