【摘要】 磷酸盐氧同位素在古气候重建和地表水富营养化研究中得到了广泛的应用。本文介绍了自20世纪60年代以来磷酸盐中18 O同位素测试的8种方法,并对它们进行了对比和评价,认为最近发展起来的在线高温热解法(HTR-CF-IRMS)和激光技术在我国具有推广应用前景;对使用磷酸盐氧同位素恢复古气候做了详细报道,其优点是P-O键能够抵抗成岩蚀变作用,δ18 OPO4值反映了源的同位素组成,在平衡时水和磷酸盐之间的氧同位素分馏值仅仅是温度的函数,可用于计算古气温;大量资料证实,使用磷酸盐氧同位素可以识别河、湖泊和海洋中磷酸盐来源,指示富营养化程度,研究磷酸盐的生物地球化学演变过程,因此在我国应当使用磷酸盐18 O、硝酸盐15 N和18 O同位素组成大力开展富营养化研究;最后提出5点建议,特别是应当加强磷矿开采、矿山排水、尾矿淋滤扩散及生物地球化学作用中磷酸盐氧同位素的研究,从源头阻断污染源。更多还原

【Abstract】 Phosphate oxygen isotope has been widely used in the study of the paleoclimate reconstruction and eutrophication of surface water.This paper introduces eight methods of phosphate 18O isotope tests since the 1960 s,and carries out comparison and evaluation on them.Newly developed online high temperature pyrolysis(HTR-CF-IRMS)and laser technology have a prospect of popularization and application in our country.The method of using phosphate oxygen isotope to restore paleoclimate is reported in detail,and its advantage is that P-O bond can withstand diagenetic alteration.δ18OPO4values reflect the isotope composition of the source,and oxygen isotope fractionation between water and phosphate is only considered as a function of temperature during the balance,which can be used to calculate paleo-temperature.The eutrophication of surface water is a hot topic attracting much attention from academia in the world.Large amounts of data have confirmed that using phosphate oxygen isotope can identify the source of phosphate in rivers,lakes and oceans,indicate the eutrophication degree,and study the biogeochemical evolution process of phosphate.In our country 18O isotope of phosphate and 15N and 18O isotope of nitrate should be used to develop the research of eutrophication.Finally this paper proposes 5suggestions,in which it is emphasised that we should do more research on phosphate rock mining,mine drainage,tailings leaching diffusion and biogeochemical effects of phosphate oxygen isotope so as to block pollution from the sources.更多还原