沉积物中生物硅的测定及其古气候意义

BIOGENETIC SILICA IN LAKE SEDIMENTS:DETERMINATION AND PALEOCLIMATE SIGNIFICANCE

生物硅是湖泊沉积物中的重要组分,多数来源于硅藻壳的沉积,其丰度跟湖泊物理化学特征息息相关。生物硅是湖泊生产率变化的重要指标之一。在古气候、古环境变化研究中,生物硅是反映古湖泊生产率的重要指标。评述了生物硅含量提取及测定中存在的一些问题,对非生源硅的校正进行了讨论,并对生物硅在古气候变化研究中的局限性做了阐述。最后,提出了生物硅含量测定及应用需注意的问题。

The biogenetic silica is an important fraction of lake sediments, of which most derives from the deposition of diatoms. The abundance of diatom is closely related to the lake water chemistry and its productivity, which depends upon the local environment around the lake. Recently, biogenetic sili- ca has gradually become an effective mean for investigation of environmental changes internationally. In this paper, we reviewed the factors that influence the production and preservation of biogenetic silica, and discussed the problems existing in the determination of biogenetic silica, and its application in paleoclimate study. Suggestions are made as well for better determination of biogenetic silica.