大气环境变化的泥炭地质档案

Atmospheric Environmental Changes Records from Peat Bogs:a Review

雨养泥炭沼泽是一种重要的泥炭沼泽类型,具有全球广泛分布的特点,其养分补给主要源于大气降水(包括雨、雪和空气尘埃)。它是一个记录大气环境变化的积极的信息储备系统,记录有大气输入的海盐气溶胶、沙尘颗粒、酸沉降、重金属和有机污染物等信息。采用地质定年技术将泥炭深度剖面转化到年代坐标上,并结合泥炭生物地球化学指标检测分析,提取反映这些信息的代用指标,是重建大气环境的变化历史的有效方法。本文讨论了泥炭沉积地球化学行为对沼泽定年和地质记录研究的意义,综述了泥炭沼泽常用的定年方法,总结了大量利用泥炭地质档案反演海洋、岩石—土壤及人类社会对大气环境变化的影响历史的研究,并在此基础上展望了大气环境变化的泥炭档案研究。

An ombrotrophic peat bog is a domed peatland in which the surface peat layers are hydrologically isolated from the influence of local ground and surface water,and are fed exclusively by atmospheric deposition consisting of both soild particles and mineral substances dissolved in rain water.It has proven to be a good continental geochemical archive,and has the unique advantage of a wide global distribution.It preserves intact atmospheric environmental changes＇ signatures including sea-salt aerosol,soil-dust,acid deposition,heavy metals,and organic pollutants. An efficient method to reconstruct a history of atmospheric environmental variation includes a chronological framework using geological dating techniques followed by biogeochemical analysis of a wide range of proxies. This paper reviews the approaches used to establish depth—age relationships in peat chronologies,and summarizes a large number of informed studies relative to deducing historical influence of ocean,rock—soil and human society on atmosphere. Finally,the slightly insufficient parts as well as the prospect of peat bog archives towards atmospheric variations are put forward.