岱海湖泊沉积物频率磁化率对历史时期环境变化的反映

IMPLICATION OF MAGNETIC FREQUENCY DEPENDENT SUSCEPTIBILITY ON ENVIRONMENTAL VARIATION FROM LACUSTRINE SEDIMENT IN DAIHAI LAKE

在探讨封闭湖泊沉积物频率磁化率的环境意义的基础上，根据岱海ＤＨ３２孔湖泊沉积物磁化率的测量结果，结合粒度、孢粉、历史资料和硅藻分析结果，对岱海历史时期的环境变化进行了探讨。研究认为：历史时期内陆封闭湖泊沉积物频率磁化率高值段指示气候偏湿阶段；低值段指示气候干旱阶段；ＤＨ３２孔湖泊沉积物频率磁化率反映的近３００年来岱海气候变化可划分七个阶段，并与粒度、孢粉、硅藻和历史资料的分析结果基本一致。湖泊沉积物频率磁化率是恢复历史时期环境变化的重要环境指标之一。

On the basis of discissing the environmental significance of magnetic susceptibility of lake sediment, the historical environmental variations have been studied from Daihai DH 32 Core with the analysis of granulomtry, sporo pollen, historical data and diatom determination. It is believed that during the historical periods the higher value of magnetic frequency dependent susceptibility in lake sediments coincided with the wet climate, and the lower value related with the dry climate. The climate change in the past 300 years implicated by magnetic frequency dependent susceptibility from DH32 Core can be divided into seven periods which mostly coresponded with the analysis of granulomtry, sporo pollen, historical data and diatom determination. The magnetic frequency dependent susceptibility of lacustrine sediment is one of the main environmental indexes for reconstructing historical environmental variations.